View source for Glyphosate

{{short description|Systemic herbicide and crop desiccant}}
{{about|the chemical alone|herbicides based on it|Glyphosate-based herbicides|the brand-name formulation developed by Monsanto|Roundup (herbicide)}}
{{Distinguish|Glufosinate}}
{{pp|small=yes}}
{{Use mdy dates|date=March 2016}}
{{Use American English|date=May 2018}}
{{chembox
| Verifiedfields = changed
| Watchedfields = changed
| verifiedrevid = 443847907
| Name = Glyphosate
| pronounce = {{IPAc-en|ˈ|ɡ|l|ɪ|f|ə|s|eɪ|t|,_|ˈ|ɡ|l|aɪ|f|ə|-}},<ref>{{cite Merriam-Webster|glyphosate|access-date=June 28, 2020}}</ref> {{IPAc-en|ɡ|l|aɪ|ˈ|f|ɒ|s|eɪ|t}}<ref>{{cite Dictionary.com|glyphosate|access-date=June 28, 2020}}</ref><ref>{{cite American Heritage Dictionary|glyphosate|access-date=June 28, 2020}}</ref>
| ImageFile1 = Glyphosate.svg
| ImageCaption1 = Idealised [[skeletal formula]] of the uncharged molecule
| ImageFile2 = Glyphosate-from-xtal-view-2-3D-bs-17.png
| ImageCaption2 = [[Ball-and-stick model]] of the [[zwitterion]] (charged form), based on the [[crystal structure]]<ref name="PHOGLY05">{{ cite journal | url = https://doi.org/10.5517/ccdc.csd.cc2dmhvd | title = CSD Entry: PHOGLY05 | website = [[Cambridge Structural Database]]: Access Structures | year = 2022 | publisher = [[Cambridge Crystallographic Data Centre]] | doi = 10.5517/ccdc.csd.cc2dmhvd | access-date = 2023-11-04 | last1 = Wilson | first1 = C. J. G. | last2 = Wood | first2 = P. A. | last3 = Parsons | first3 = S. }}</ref><ref>{{ cite journal | first1 = Cameron J. G. | last1 = Wilson | first2 = Peter A. | last2 = Wood | first3 = Simon | last3 = Parsons | title = Discerning subtle high-pressure phase transitions in glyphosate | journal = [[CrystEngComm]] | year = 2023 | volume = 25 | issue = 6 | pages = 988–997 | doi = 10.1039/D2CE01616H | doi-access = free | hdl = 20.500.11820/e81bbc4f-a6d1-4e16-a288-6eb9ff626485 | hdl-access = free }}</ref>
| IUPACName = ''N''-(Phosphonomethyl)glycine
| SystematicName = [(Phosphonomethyl)amino]acetic acid
| OtherNames = 
|Section1={{Chembox Identifiers
| CASNo = 1071-83-6
| CASNo_Ref = {{cascite|correct|CAS}}
| CASNo_Comment = (free acid)
| CASNo1_Ref = {{cascite|changed|CAS}}
| CASNo1 = 38641-94-0
| CASNo1_Comment = (isopropylammonium salt)
| CASNo2_Ref = {{cascite|changed|CAS}}
| CASNo2 = 70393-85-0
| CASNo2_Comment = (sesquisodium salt)
| CASNo3_Ref = {{cascite|changed|CAS}}
| CASNo3 = 81591-81-3
| CASNo3_Comment = ([[trimethylsulfonium]] salt)<!-- 38641-94-0 also verified at CAS Common Chemistry, 70393-85-0 and 81591-81-3 verified at ESIS -->
| Beilstein = 2045054
| ChEBI_Ref = {{ebicite|correct|EBI}}
| ChEBI = 27744
| ChEMBL_Ref = {{ebicite|correct|EBI}}
| ChEMBL = 95764
| DrugBank = DB04539
| EC_number = 213-997-4 <!-- 254-056-8 for isopropylammonium salt, 274-591-0 for sesquisodium salt -->
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 3376
| Gmelin = 279222
| KEGG_Ref = {{keggcite|correct|kegg}}
| KEGG = C01705
| PubChem = 3496
| RTECS = MC1075000
| UNNumber = 3077 2783
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = 4632WW1X5A
| InChI = 1/C3H8NO5P/c5-3(6)1-4-2-10(7,8)9/h4H,1-2H2,(H,5,6)(H2,7,8,9)
| InChIKey = XDDAORKBJWWYJS-UHFFFAOYAE
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/C3H8NO5P/c5-3(6)1-4-2-10(7,8)9/h4H,1-2H2,(H,5,6)(H2,7,8,9)
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = XDDAORKBJWWYJS-UHFFFAOYSA-N
| SMILES = O=C(O)CNCP(=O)(O)O
}}
|Section2 = {{Chembox Properties
| Properties_ref = <ref name="EHC">{{EHC-ref|number=159|name=Glyphosate|date=1994|isbn=92-4-157159-4}}</ref>
| C=3 | H=8 | N=1 | O=5 | P=1
| Appearance = white crystalline powder
| Density = 1.704 (20&nbsp;°C)
| MeltingPtC = 184.5
| BoilingPt_notes= decomposes
| BoilingPtC = 187
| Solubility = 1.01 g/100 mL (20&nbsp;°C)
| LogP = −2.8
| pKa = <2, 2.6, 5.6, 10.6
  }}
|Section7={{Chembox Hazards
| Hazards_ref = <ref name="EHC"/><ref>{{CLP Regulation|index=607-315-00-8|pages=570, 1100}}</ref>
| ExternalSDS = [http://www.inchem.org/documents/icsc/icsc/eics0160.htm InChem MSDS]
| GHSPictograms = {{GHS05|Eye Dam. 1}}{{GHS09|Aquatic Chronic 2}}
| GHSSignalWord = DANGER
| HPhrases = {{H-phrases|318|411}}
| PPhrases = {{P-phrases|273|280|305+351+338|310|501}}
| FlashPt = Non-flammable
  }}
}}

'''Glyphosate''' ([[IUPAC name]]: '''''N''-(phosphonomethyl)glycine''') is a broad-spectrum [[systemic herbicide]] and [[crop desiccant]]. It is an organophosphorus compound, specifically a [[phosphonate]], which acts by [[EPSP inhibitor|inhibiting the plant enzyme 5-enolpyruvylshikimate-3-phosphate synthase]] (EPSP). It is used to kill [[weed]]s, especially annual [[Forbs|broadleaf weeds]] and grasses that compete with [[crop]]s. Its herbicidal effectiveness was discovered by [[Monsanto]] chemist [[John E. Franz]] in 1970. Monsanto brought it to market for agricultural use in 1974 under the trade name [[Roundup (herbicide)|Roundup]]. Monsanto's last commercially relevant United States [[patent]] expired in 2000.

Farmers quickly adopted glyphosate for agricultural weed control, especially after Monsanto introduced glyphosate-resistant [[Roundup Ready crops]], enabling farmers to kill weeds without killing their crops. In 2007, glyphosate was the most used herbicide in the United States' agricultural sector and the second-most used (after [[2,4-Dichlorophenoxyacetic acid|2,4-D]]) in home and garden, government and industry, and commercial applications.<ref name="EPAusage">{{cite web | title=2006-2007 Pesticide Market Estimates: Usage (Page 2) - Pesticides - US EPA | website=epa.gov | date=2011-02-18 | url=https://www.epa.gov/opp00001/pestsales/07pestsales/usage2007_2.htm#3_6 | archive-url=https://web.archive.org/web/20150626092432/https://www.epa.gov/opp00001/pestsales/07pestsales/usage2007_2.htm#3_6 | archive-date=2015-06-26 | url-status=dead | access-date=2021-11-30}}</ref> From the late 1970s to 2016, there was a 100-fold increase in the frequency and volume of application of [[glyphosate-based herbicides]] (GBHs) worldwide, with further increases expected in the future.

Glyphosate is absorbed through foliage, and minimally through roots, and from there translocated to growing points. It inhibits [[EPSP synthase]], a plant enzyme involved in the synthesis of three [[aromatic amino acid]]s: [[tyrosine]], [[tryptophan]], and [[phenylalanine]]. It is therefore effective only on actively growing plants and is not effective as a [[preemergent herbicides|pre-emergence herbicide]]. Crops have been [[genetic engineering|genetically engineered]] to be tolerant of glyphosate (e.g. [[Roundup Ready soybean]], the first Roundup Ready crop, also created by Monsanto), which allows farmers to use glyphosate as a post-emergence herbicide against weeds.

While glyphosate and formulations such as Roundup have been approved by regulatory bodies worldwide, concerns about their effects on humans and the environment have persisted.<ref name="biomedcentral_2016">{{cite journal | title=Concerns over use of glyphosate-based herbicides and risks associated with exposures: a consensus statement | journal=[[Environmental Health (journal)|Environmental Health]]| date=February 17, 2016 |first1=John Peterson |last1=Myers |first2=Michael N. |last2=Antoniou |first3=Bruce |last3=Blumberg |first4=Lynn |last4=Carroll |first5=Theo |last5=Colborn |first6=Lorne G. |last6=Everett |first7=Michael |last7=Hansen |first8=Philip J. |last8=Landrigan |first9=Bruce P. |last9=Lanphear |first10=Robin |last10=Mesnage |first11=Laura N. |last11=Vandenberg |first12=Frederick S. |last12=vom Saal |first13=Wade V. |last13=Welshons |first14=Charles M. |last14=Benbroo | name-list-style = vanc | pages=13 |doi=10.1186/s12940-016-0117-0 | pmid=26883814 |pmc = 4756530|volume=15 |number=19| bibcode=2016EnvHe..15...19M| doi-access=free}}</ref><ref name=NatureonWHO2015/> A number of regulatory and scholarly reviews have evaluated the relative toxicity of glyphosate as an herbicide. The WHO and [[Food and Agriculture Organization|FAO]] Joint committee on pesticide residues issued a report in 2016 stating the use of glyphosate formulations does not necessarily constitute a health risk, and giving an [[acceptable daily intake]] limit of 1 milligram per kilogram of body weight per day for chronic toxicity.<ref>{{Cite web|url=https://www.who.int/foodsafety/jmprsummary2016.pdf|title=Report of the Joint Committee on Pesticide Residues, WHO/FAO, Geneva, 16 May, 2016}}</ref>

The [[scientific consensus|consensus]] among national pesticide regulatory agencies and scientific organizations is that labeled uses of glyphosate have demonstrated no evidence of human carcinogenicity.<ref name=Tarazona>{{cite journal |last1=Tarazona |first1=Jose V. |last2=Court-Marques |first2=Daniele |last3=Tiramani |first3=Manuela |last4=Reich |first4=Hermine |last5=Pfeil |first5=Rudolf |last6=Istace |first6=Frederique |last7=Crivellente |first7=Federica |title=Glyphosate toxicity and carcinogenicity: a review of the scientific basis of the European Union assessment and its differences with IARC |journal=[[Archives of Toxicology]]|date=3 April 2017 |volume=91 |issue=8 |pages=2723–43 |doi=10.1007/s00204-017-1962-5 |pmid=28374158 |pmc=5515989 |bibcode=2017ArTox..91.2723T }}</ref> In March 2015, the [[World Health Organization]]'s [[International Agency for Research on Cancer]] (IARC) classified glyphosate as "probably carcinogenic in humans" ([[List of IARC Group 2A carcinogens|category 2A]]) based on epidemiological studies, animal studies, and ''[[in vitro]]'' studies.<ref name="NatureonWHO2015" /><ref name="Lancet20March2015">{{cite journal | vauthors = Guyton KZ, Loomis D, Grosse Y, El Ghissassi F, Benbrahim-Tallaa L, Guha N, Scoccianti C, Mattock H, Straif K | title = Carcinogenicity of tetrachlorvinphos, parathion, malathion, diazinon, and glyphosate | journal =[[The Lancet Oncology]]| volume = 16 | issue = 5 | pages = 490–91 | date = May 2015 | pmid = 25801782 | doi = 10.1016/S1470-2045(15)70134-8 }}</ref><ref name="IARC20March2015" /><ref name="iarcmono">{{cite journal | url = https://monographs.iarc.fr/wp-content/uploads/2018/06/mono112-10.pdf | title = Glyphosate | journal = IARC Monographs on the Evaluation of Carcinogenic Risks to Humans | volume = 112 | date = 11 August 2016 | publisher = [[International Agency for Research on Cancer]] | access-date = July 31, 2019 | archive-date = July 30, 2019 | archive-url = https://web.archive.org/web/20190730162330/https://monographs.iarc.fr/wp-content/uploads/2018/06/mono112-10.pdf | url-status = dead }}</ref>  In contrast, the [[European Food Safety Authority]] concluded in November 2015 that "the substance is unlikely to be [[Genotoxicity|genotoxic]] (i.e. damaging to [[DNA]]) or to pose a [[carcinogen]]ic threat to humans", later clarifying that while carcinogenic glyphosate-containing formulations may exist, studies that "look solely at the active substance glyphosate do not show this effect".<ref>{{Cite web|url=https://www.efsa.europa.eu/sites/default/files/corporate_publications/files/efsaexplainsglyphosate151112en.pdf|title=European Food Safety Authority – Glyphosate report|website=[[EFSA]]|access-date=May 23, 2016}}</ref><ref>{{Cite web|url=http://www.efsa.europa.eu/en/press/news/151112|title=Glyphosate: EFSA updates toxicological profile|website=[[European Food Safety Authority]] |access-date=2016-05-23|date=November 12, 2015}}</ref> In 2017, the [[European Chemicals Agency]] (ECHA) classified glyphosate as causing serious eye damage and as toxic to aquatic life but did not find evidence implicating it as a carcinogen, a mutagen, toxic to reproduction, nor toxic to specific organs.<ref>{{cite web|url=https://echa.europa.eu/-/glyphosate-not-classified-as-a-carcinogen-by-echa|title=Glyphosate not classified as a carcinogen by ECHA|date=15 March 2017 |publisher=ECHA}}</ref>

==Discovery==
Glyphosate was first synthesized in 1950 by Swiss chemist Henry Martin, who worked for the Swiss company [[Cilag]]. The work was never published.<ref name=Dill>{{cite book | editor-last1 = Nandula | editor-first1 = Vijay K. | title = Glyphosate Resistance in Crops and Weeds: History, Development, and Management | first1 = Gerald M. | last1 = Dill | first2 = R. Douglas | last2 = Sammons | first3 = Paul C. | last3 = Feng | first4 = Frank | last4 = Kohn | first5 = Keith | last5 = Kretzmer | first6 = Akbar | last6 = Mehrsheikh | first7 = Marion | last7 = Bleeke | first8 = Joy L. | last8 = Honegger | first9 = Donna | last9 = Farmer | first10 = Dan | last10 = Wright | first11 = Eric A. | last11 = Haupfear | name-list-style = vanc | chapter = Glyphosate: Discovery, Development, Applications, and Properties | chapter-url = http://media.johnwiley.com.au/product_data/excerpt/10/04704103/0470410310.pdf | date = 2010 | publisher =[[John Wiley & Sons, Inc.]]| location =[[Hoboken, NJ]]| isbn = 978-0-470-41031-8 }}</ref>{{rp|1}} Early studies found it to be a weak chemical [[Chelation|chelating agent]].<ref name="Casida-2017" /><ref>{{cite journal|title=Comments for Mertens et al. (2018), Glyphosate, a chelating agent—relevant for ecological risk assessment?|first1=John T.|last1=Swarthout|first2=Marian S.|last2=Bleeke|first3=John L.|last3=Vicini|journal=Environmental Science and Pollution Research International|date=June 16, 2018|volume=25|issue=27|pages=27662–3|doi=10.1007/s11356-018-2506-0|pmc=6132386|pmid=29907899|bibcode=2018ESPR...2527662S }}</ref>

Somewhat later, glyphosate was independently discovered in the [[United States]] at Monsanto in 1970. [[Monsanto]] chemists had synthesized about 100 [[Derivative (chemistry)|derivatives]] of [[aminomethylphosphonic acid]] as potential [[Water softening|water-softening]] agents. Two were found to have weak herbicidal activity, and [[John E. Franz]], a chemist at Monsanto, was asked to try to make analogs with stronger herbicidal activity. Glyphosate was the third analog he made.<ref name=Dill/>{{rp|1–2}}<ref name="pmid11248008">{{cite journal | vauthors = Alibhai MF, Stallings WC | title = Closing down on glyphosate inhibition&nbsp;– with a new structure for drug discovery | journal =[[Proceedings of the National Academy of Sciences of the United States of America]]| volume = 98 | issue = 6 | pages = 2944–46 | date = Mar 2001 | pmid = 11248008 | pmc = 33334 | doi = 10.1073/pnas.061025898 | bibcode = 2001PNAS...98.2944A | jstor = 3055165 | doi-access = free }}</ref><ref>{{cite journal|title=Monsanto's John E. Franz Wins 1990 Perkin Medal|journal=[[Chemical & Engineering News]]|date=12 March 1990|volume=68|issue=11|pages=29–30|doi=10.1021/cen-v068n011.p029 }}</ref> Franz received the [[National Medal of Technology]] of the United States in 1987 and the [[Perkin Medal]] for Applied Chemistry in 1990 for his discoveries.<ref name="urlThe National Medal of Technology and Innovation Recipients – 1987">{{cite web | url = http://www.uspto.gov/about/nmti/recipients/1987.jsp | title = The National Medal of Technology and Innovation Recipients – 1987 | publisher = The [[United States Patent and Trademark Office]]| access-date = 2012-11-29 }}</ref><ref>{{cite journal | title = People: Monsanto Scientist John E. Franz Wins 1990 Perkin Medal For Applied Chemistry | journal =[[The Scientist (magazine)|The Scientist]]| vauthors = Stong C | date = May 1990 | volume = 4 | issue = 10 | pages = 28 | url = http://classic.the-scientist.com/?articles.view/articleNo/11141/|archive-url=https://web.archive.org/web/20140416133120/http://classic.the-scientist.com/?articles.view/articleNo/11141/title/People--Monsanto-Scientist-John-E--Franz-Wins-1990-Perkin-Medal-For-Applied-Chemistry/|url-status=dead|archive-date=2014-04-16 }}</ref><ref name="SCI Perkin Medal">{{cite web|title=SCI Perkin Medal|url=https://www.sciencehistory.org/sci-perkin-medal|website=[[Science History Institute]]|access-date=24 March 2018|date=May 31, 2016}}</ref>

Monsanto developed and patented the use of glyphosate to kill weeds in the early 1970s and first brought it to market in 1974, under the Roundup brandname.<ref name="Duke" /><ref name="monsantofaq">{{cite web | url=https://monsanto.com/app/uploads/2017/06/back_history.pdf | title=History of Monsanto's Glyphosate Herbicides | publisher=[[Monsanto]]| access-date=20 December 2015 | archive-date=August 7, 2018 | archive-url=https://web.archive.org/web/20180807095908/https://monsanto.com/app/uploads/2017/06/back_history.pdf | url-status=dead }}</ref> While its initial patent<ref>{{cite patent| country = US| number = 3799758 | status = application| title = N-phosphonomethyl-glycine phytotoxicant compositions | pubdate = 1974-03-26| fdate = 1971-08-09| pridate = 1971-08-09| invent1 = John E. Franz| assign1 = Monsanto Company}}</ref> expired in 1991, Monsanto retained exclusive rights in the United States until its patent<ref>{{cite patent| country = US| number = 4405531 | status = application| title = Salts of N-phosphonomethylglycine| pubdate = 1983-09-20| fdate = 1982-03-08| pridate = 1975-11-10| invent1 = John E. Franz| assign1 = Monsanto Company}}</ref> on the isopropylamine salt expired in September 2000.<ref>{{cite web |url=http://www.frost.com/prod/servlet/market-insight-print.pag?docid=JEVS-5N2CZG |title=The Glyphosate Market: A 'Roundup' |last1=Fernandez |first1=Ivan |date=2002-05-15 |website=[[Frost & Sullivan]]|access-date=2015-03-10 |archive-url=https://web.archive.org/web/20160304085158/http://www.frost.com/prod/servlet/market-insight-print.pag?docid=JEVS-5N2CZG |archive-date=2016-03-04}}</ref>

In 2008, United States Department of Agriculture [[Agricultural Research Service]] (USDA ARS) scientist Stephen O. Duke and Stephen B. Powles – an Australian weed expert – described glyphosate as a "virtually ideal" herbicide.<ref name=Duke>{{citation |first1=Stephen O. |last1=Duke |first2=Stephen B. |last2=Powles |name-list-style=vanc |date=2008 |url=http://naldc.nal.usda.gov/download/17918/PDF |format=PDF |title=Glyphosate: a once-in-a-century herbicide: Mini-review |journal=[[Pest Management Science]]|volume=64 |issue=4 |pages=319–25 |doi=10.1002/ps.1518 |pmid=18273882 |access-date=April 13, 2014 |archive-date=July 2, 2019 |archive-url=https://web.archive.org/web/20190702211642/https://naldc.nal.usda.gov/download/17918/PDF |url-status=dead }}</ref> In 2010 Powles stated: "glyphosate is a one in a 100-year discovery that is as important for reliable global food production as penicillin is for battling disease."<ref name="PNAS_2010_Powles">{{cite journal | vauthors = Powles SB | title = Gene amplification delivers glyphosate-resistant weed evolution | journal =[[Proceedings of the National Academy of Sciences of the United States of America]]| volume = 107 | issue = 3 | pages = 955–56 | date = January 2010 | pmid = 20080659 | pmc = 2824278 | doi = 10.1073/pnas.0913433107| bibcode = 2010PNAS..107..955P | doi-access = free }}</ref>

As of April 2017, the Canadian government stated that glyphosate was "the most widely used herbicide in Canada",<ref name=pmrare/> at which date the product labels were revised to ensure a limit of 20% [[Polyethoxylated tallow amine|POEA]] by weight.<ref name=pmrare>{{cite web|url=https://www.canada.ca/en/health-canada/services/consumer-product-safety/reports-publications/pesticides-pest-management/fact-sheets-other-resources/request-special-review-glyphosate-herbicides-containing-polyethoxylated-tallowamine/frequently-asked-questions.html|title=Frequently Asked Questions on the Re-evaluation of Glyphosate|publisher=[[Pest Management Regulatory Agency of Canada]]|date=28 Apr 2017|access-date=10 May 2018}}</ref>{{failed verification|date=October 2020}} [[Health Canada]]'s [[Pest Management Regulatory Agency]] found no risk to humans or the environment at that 20% limit, and that all products registered in [[Canada]] at that time were at or below that limit.

==Chemistry==
[[File:Glyphosate Dissociation V.1.svg|thumb|upright|Ionic states]]
Glyphosate is an aminophosphonic analogue of the natural amino acid [[glycine]] and, like all amino acids, exists in different ionic states depending on [[pH]]. Both the [[phosphonic acid]] and [[carboxylic acid]] moieties can be ionised and the [[amine]] group can be protonated and the substance exists as a series of [[zwitterion]]s. Glyphosate is soluble in water to 12&nbsp;g/L at room temperature. The original synthetic approach to glyphosate involved the reaction of [[phosphorus trichloride]] with [[formaldehyde]] followed by [[hydrolysis]] to yield a [[phosphonate]]. Glycine is then reacted with this phosphonate to yield glyphosate, and its name is taken as a contraction of the compounds used in this synthesis step, namely '''gly'''cine and a '''phos'''phon'''ate'''.<ref name = Chenier>{{cite book|url = https://books.google.com/books?id=gbHeBwAAQBAJ&q=industrial+synthesis+glyphosate&pg=PA384|title = Survey of Industrial Chemistry|author = Chenier, Philip J.|page = 384|year = 2012|publisher = [[Springer Science+Business Media]]|edition = 3rd|isbn = 978-1461506034}}</ref>

* PCl<sub>3</sub> + H<sub>2</sub>CO → Cl<sub>2</sub>P(=O)−CH<sub>2</sub>Cl
* Cl<sub>2</sub>P(=O)−CH<sub>2</sub>Cl + 2&nbsp;H<sub>2</sub>O → (HO)<sub>2</sub>P(=O)−CH<sub>2</sub>Cl + 2&nbsp;HCl
* (HO)<sub>2</sub>P(=O)−CH<sub>2</sub>Cl + H<sub>2</sub>N−CH<sub>2</sub>−COOH → (HO)<sub>2</sub>P(=O)−CH<sub>2</sub>−NH−CH<sub>2</sub>−COOH + HCl

The main deactivation path for glyphosate is hydrolysis to [[aminomethylphosphonic acid]].<ref name="urlwww.cdpr.ca.gov">{{cite web | url = http://www.cdpr.ca.gov/docs/emon/pubs/fatememo/glyphos.pdf | title = Environmental Fate of Glyphosate | vauthors = Schuette J | publisher = Department of Pesticide Regulation, State of California | access-date = June 4, 2012 | archive-url = https://web.archive.org/web/20120420013222/http://www.cdpr.ca.gov/docs/emon/pubs/fatememo/glyphos.pdf | archive-date = April 20, 2012 | url-status = dead }}</ref>

===Synthesis===
Two main approaches are used to synthesize glyphosate industrially, both of which proceed via the [[Kabachnik–Fields reaction]]. The first is to react [[iminodiacetic acid]] and [[formaldehyde]] with [[phosphorous acid]] (sometimes formed ''in situ'' from [[phosphorus trichloride]] using the water generated by the [[Mannich reaction]] of the first two reagents). [[Decarboxylation]] of the [[hydrophosphonylation]] product gives the desired glyphosate product. Iminodiacetic acid is usually prepared on-site by various methods depending on reagent availability.<ref name = Dill />

[[File:Glyphosate synthesis from iminodiacetic acid.svg|frameless|upright=3|[[Iminodiacetic acid]] approach to glyphosate synthesis]]

The second uses [[glycine]] in place of iminodiacetic acid. This avoids the need for decarboxylation but requires more careful control of [[stoichiometry]], as the  primary amine can react with any excess formaldehyde to form bishydroxymethylglycine, which must be hydrolysed during the [[Work-up (chemistry)|work-up]] to give the desired product.<ref name = Dill />

[[File:Glyphosate synthesis from dimethyl phosphite.svg|frameless|upright=2|Glyphosate synthesis from dimethyl phosphite]]

This synthetic approach is responsible for a substantial portion of the production of glyphosate in China, with considerable work having gone into recycling the triethylamine and methanol solvents.<ref name = Dill /> Progress has also been made in attempting to eliminate the need for triethylamine altogether.<ref>{{cite journal|title = Study on a New Synthesis Approach of Glyphosate | vauthors = Zhou J, Li J, An R, Yuan H, Yu F | journal = [[J. Agric. Food Chem.]]|year = 2012|volume = 60|issue = 25|pages = 6279–85|doi = 10.1021/jf301025p| pmid = 22676441 }}</ref>

===Impurities===
Technical grade glyphosate is a white powder which, according to [[FAO]] specification, should contain not less than 95% glyphosate. [[Formaldehyde]], classified as a known human carcinogen,
<ref name="IARC2006">{{cite book |last1=International Agency for Research on Cancer |title=IARC Monographs on the Evaluation of Carcinogenic Risks to Humans Volume 88: Formaldehyde, 2-Butoxyethanol and 1-''tert''-Butoxypropan-2-ol. |date=2006 |publisher=IARC/WHO |location=Lyon |url=http://monographs.iarc.fr/ENG/Monographs/vol88/index.phpExit|isbn=978-9283212881 }}</ref>
<ref name="NTP2011">{{cite book |last1=National Toxicology Program |title=Report on Carcinogens |date=June 2011 |publisher=Department of Health and Human Services, Public Health Service, National Toxicology Program |edition=  12th }}</ref> 
and [[N-Nitrosoglyphosate|''N''-nitrosoglyphosate]], have been identified as toxicologically relevant impurities.<ref name="ImpuritiesFAO2014">{{cite book |last1=FAO |title=FAO specifications and evaluations for agricultural pesticides: glyphosate |date=2014 |publisher=. Food and Agriculture Organization of the United Nations |page=5 |url=http://www.fao.org/fileadmin/templates/agphome/documents/Pests_Pesticides/Specs/Glypho_2014.pdf}}</ref> The FAO specification limits the formaldehyde concentration to a maximum of 1.3 g/kg glyphosate. ''N''-Nitrosoglyphosate, "belonging to a group of impurities of particular concern as they can be activated to genotoxic carcinogens",<ref name="ESFApeerRev2015">{{cite journal |last1=European Food Safety Authority |title=Conclusion on the peer review of the pesticide risk assessment of the active substance glyphosate |journal= EFSA Journal|date=2015 |volume=13 |issue=11:4302 |page=10 |doi=10.2903/j.efsa.2015.4302 |doi-access=free }}</ref> should not exceed 1 ppm.<ref name = "ImpuritiesFAO2014"/>

==Formulations==
{{Main|Glyphosate-based herbicides}}
[[File:Roundup herbicide logo.jpg|thumb|upright|Monsanto's [[Roundup (herbicide)|Roundup]] is the earliest formulation]]
<!-- proprietary? {{Expand section|1=examples of formulations of glyphosate – what are other surfactants and adjuvants? what are their qualities? Which are best for various purposes of farmers? What are the risks of those chemicals? |date=September 2012}} -->Glyphosate is marketed in the United States and worldwide by many [[agrochemical]] companies, in different solution strengths and with various [[Agricultural spray adjuvant|adjuvants]], under dozens of tradenames.<ref>Farm Chemicals International [http://www.farmchemicalsinternational.com/crop-protection-database/#//product/brief/203900 Glyphosate entry in Crop Protection Database]</ref><ref name=AlbertaQuick2015/><ref name="urlISU Weed Science Online – Glyphosate – A Review">{{cite web | url = http://www.weeds.iastate.edu/mgmt/2001/glyphosate%20review.htm#Glyphosate%20Products | series = ISU Weed Science Online | title = Glyphosate: a Review | last1 = Hartzler | first1 = Bob | publisher =[[Iowa State University Extension]]| access-date = August 26, 2012 | archive-url = https://web.archive.org/web/20180518051215/http://www.weeds.iastate.edu/mgmt/2001/glyphosate%20review.htm#Glyphosate%20Products | archive-date = May 18, 2018 | url-status = dead }}</ref><ref name="Weed Handbook Glyphosate">{{cite web | url = http://www.invasive.org/gist/products/handbook/14.Glyphosate.pdf | title = Glyphosate | vauthors = Tu M, Hurd C, Robison R, Randall JM | date = November 1, 2001| work = Weed Control Methods Handbook | publisher = The Nature Conservancy }}</ref> As of 2010, more than 750 glyphosate products were on the market.<ref>National Pesticide Information Center. Last updated September 2010 [http://npic.orst.edu/factsheets/glyphogen.html Glyphosate General Fact Sheet]</ref> In 2012, about half of the total global consumption of glyphosate by volume was for agricultural crops,<ref name=ReuterMarkets2014/> with [[forestry]] comprising another important market.<ref>[https://www.monsanto.ca/products/Documents/vision_label_en.pdf monsanto.ca: "Vision Silviculture Herbicide"] {{Webarchive|url=https://web.archive.org/web/20160407094242/http://www.monsanto.ca/products/Documents/vision_label_en.pdf |date=April 7, 2016 }}, 03-FEB-2011</ref> Asia and the Pacific was the largest and fastest growing regional market.<ref name="ReuterMarkets2014">{{cite news|url=https://www.reuters.com/article/2014/04/30/research-and-markets-idUSnBw306202a+100+BSW20140430|title=Press Release: Research and Markets: Global Glyphosate Market for Genetically Modified and Conventional Crops 2013–2019|date=30 April 2014|work=Reuters|url-status=dead|archive-url=https://web.archive.org/web/20150924200327/https://www.reuters.com/article/2014/04/30/research-and-markets-idUSnBw306202a+100+BSW20140430|archive-date=September 24, 2015|df=mdy-all}}</ref> As of 2014, Chinese manufacturers collectively are the world's largest producers of glyphosate and its precursors<ref>China Research & Intelligence, June 5, 2013. [http://www.shcri.com/agricultural-chemicals/14-research-report-on-global-and-china-glyphosate-industry-2013-2017.html Research Report on Global and China Glyphosate Industry, 2013–2017] {{Webarchive|url=https://web.archive.org/web/20160303222042/http://www.shcri.com/agricultural-chemicals/14-research-report-on-global-and-china-glyphosate-industry-2013-2017.html |date=March 3, 2016 }}</ref> and account for about 30% of global exports.<ref name=ReuterMarkets2014/> Key manufacturers include Anhui Huaxing Chemical Industry Company, [[BASF]], [[Bayer CropScience]] (which also acquired the maker of glyphosate, [[Monsanto]]), [[Dow AgroSciences]], [[DuPont]], Jiangsu Good Harvest-Weien Agrochemical Company, Nantong Jiangshan Agrochemical & Chemicals Co., [[Nufarm]], SinoHarvest, [[Syngenta]], and Zhejiang Xinan Chemical Industrial Group Company.<ref name=ReuterMarkets2014/>

Glyphosate is an acid molecule, so it is formulated as a [[salt (chemistry)|salt]] for packaging and handling. Various salt formulations include isopropylamine, diammonium, monoammonium, or potassium as the [[counterion]]. The [[active ingredient]] of the Monsanto herbicides is the [[isopropylamine]] [[Salt (chemistry)|salt]] of glyphosate. Another important ingredient in some formulations is the [[surfactant]] [[polyethoxylated tallow amine|polyethoxylated tallow amine (POEA)]]. Some brands include more than one salt. Some companies report their product as acid equivalent (ae) of glyphosate acid, or some report it as active ingredient (ai) of glyphosate plus the salt, and others report both. To compare performance of different formulations, knowledge of how the products were formulated is needed. Given that different salts have different weights, the acid equivalent is a more accurate method of expressing and comparing concentrations.

Adjuvant loading refers to the amount of adjuvant<ref name="Tu_Randall_2003">{{cite web | url = http://www.invasive.org/gist/products/handbook/14.Glyphosate.pdf | title = Glyphosate | vauthors = Tu M, Randall JM | date = 2003-06-01 | work = Weed Control Methods Handbook | publisher = The Nature Conservancy }}</ref><ref name="urlCrops and Soils – Penn State Extension">{{cite web | url = http://extension.psu.edu/pests/weeds/control/adjuvants-for-enhancing-herbicide-performance | title = Adjuvants for Enhancing Herbicide Performance | vauthors = Curran WS, McGlamery MD, Liebl RA, Lingenfelter DD | year = 1999 | publisher =Penn State Extension }}</ref> already added to the glyphosate product. Fully loaded products contain all the necessary adjuvants, including [[surfactant]]; some contain no adjuvant system, while other products contain only a limited amount of adjuvant (minimal or partial loading) and additional surfactants must be added to the spray tank before application.<ref name=UDelFormulations>{{cite web | url = http://agdev.anr.udel.edu/weeklycropupdate/?p=96 | title = Glyphosate Formulations | vauthors = VanGessel M | work = Control Methods Handbook, Chapter 8, Adjuvants: Weekly Crop Update | publisher = University of Delaware Cooperative Extension | access-date = August 27, 2012 | archive-url = https://web.archive.org/web/20100613014135/http://agdev.anr.udel.edu/weeklycropupdate/?p=96 | archive-date = June 13, 2010 | url-status = dead }}</ref>

Products are supplied most commonly in formulations of 120, 240, 360, 480, and 680&nbsp;g/L of active ingredient. The most common formulation in agriculture is 360&nbsp;g/L, either alone or with added [[cationic surfactant]]s.<ref name=AlbertaQuick2015>Alberta Agriculture and Rural Development. April 26, 2006. [http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/faq8069 Quick Guide to Glyphosate Products – Frequently Asked Questions] {{Webarchive|url=https://web.archive.org/web/20170726123020/http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/faq8069 |date=July 26, 2017 }}</ref>

For {{Convert|360|g/L}} formulations, European regulations allow applications of up to {{Convert|12|L/ha}} for control of perennial weeds such as [[Elytrigia repens|couch grass]]. More commonly, rates of {{Convert|3|L/ha}} are practiced for control of annual weeds between crops.<ref>{{cite web|url=http://e-phy.agriculture.gouv.fr/|title=e-phy|website=e-phy.agriculture.gouv.fr}}</ref>

==Mode of action==
Glyphosate interferes with the [[shikimate pathway]], which produces the [[aromatic amino acids]] [[phenylalanine]], [[tyrosine]] and [[tryptophan]] in plants and microorganisms<ref name="Funke_2006">{{cite journal | vauthors = Funke T, Han H, Healy-Fried ML, Fischer M, Schönbrunn E | title = Molecular basis for the herbicide resistance of Roundup Ready crops | journal =[[Proceedings of the National Academy of Sciences of the United States of America]]| volume = 103 | issue = 35 | pages = 13010–15 | date = Aug 2006 | pmid = 16916934 | pmc = 1559744 | doi = 10.1073/pnas.0603638103 | bibcode = 2006PNAS..10313010F| jstor = 30050705 | doi-access = free }}</ref> – but does not exist in the genome of animals, including humans.<ref name="pmid22554242">{{cite journal | vauthors = Maeda H, Dudareva N | title = The shikimate pathway and aromatic amino Acid biosynthesis in plants | journal =[[Annual Review of Plant Biology]]| volume = 63 | pages = 73–105 | year = 2012 | issue = 1 | pmid = 22554242 | doi = 10.1146/annurev-arplant-042811-105439 | quote = The AAA pathways consist of the shikimate pathway (the prechorismate pathway) and individual postchorismate pathways leading to Trp, Phe, and Tyr.... These pathways are found in bacteria, fungi, plants, and some protists, but are absent in animals. Therefore, AAAs and some of their derivatives (vitamins) are essential nutrients in the human diet, although in animals Tyr can be synthesized from Phe by Phe hydroxylase....The absence of the AAA pathways in animals also makes these pathways attractive targets for antimicrobial agents and herbicides. }}</ref><ref name="Casida-2017">{{cite journal | last=Casida | first=John E. | title=Organophosphorus Xenobiotic Toxicology | journal=[[Annual Review of Pharmacology and Toxicology]] | publisher=[[Annual Reviews (publisher)|Annual Reviews]] | volume=57 | issue=1 | date=2017-01-06 | issn=0362-1642 | doi=10.1146/annurev-pharmtox-010716-104926 | pages=309–327| pmid=28061690 | doi-access=free }}</ref> It blocks this pathway by inhibiting the enzyme [[EPSP synthase|5-enolpyruvylshikimate-3-phosphate synthase]] (EPSPS), which [[Catalysis|catalyzes]] the reaction of [[shikimate]]-3-phosphate (S3P) and [[phosphoenolpyruvate]] to form 5-enolpyruvyl-shikimate-3-phosphate (EPSP).<ref name="pmid7396959">{{cite journal | vauthors = Steinrücken HC, Amrhein N | title = The herbicide glyphosate is a potent inhibitor of 5-enolpyruvyl-shikimic acid-3-phosphate synthase | journal =[[Biochemical and Biophysical Research Communications]]| volume = 94 | issue = 4 | pages = 1207–12 | date = Jun 1980 | pmid = 7396959 | doi = 10.1016/0006-291X(80)90547-1 }}</ref> Glyphosate is absorbed through foliage and minimally through roots, meaning that it is only effective on actively growing plants and cannot prevent seeds from germinating.<ref name="NPIC Data Sheet"/><ref name=moneuro/> After application, glyphosate is readily transported around the plant to growing roots and leaves and this [[Herbicide#Mechanism of action|systemic]] activity is important for its effectiveness.<ref name=Duke/><ref name=Dill/> Inhibiting the enzyme causes shikimate to accumulate in plant tissues and diverts energy and resources away from other processes, eventually killing the plant. While growth stops within hours of application, it takes several days for the leaves to begin [[chlorosis|turning yellow]].<ref name=hock04>{{cite book | first1 = Bertold | last1 = Hock | first2 = Erich F. | last2 = Elstner | name-list-style = vanc | title = Plant Toxicology, Fourth Edition | url = https://books.google.com/books?id=pWqBJpWnK4EC&pg=PA292 | year= 2004 | publisher=CRC Press | isbn = 978-0-203-02388-4 | pages = 292–96 }}</ref> Glyphosate may chelate [[Co2+|Co{{sup|2+}}]] which contributes to its mode of action.<ref name="Shick-Dunlap-2002">{{cite journal | last1=Shick | first1=J. Malcolm | last2=Dunlap | first2=Walter C. | title=Mycosporine-Like Amino Acids and Related Gadusols: Biosynthesis, Accumulation, and UV-Protective Functions in Aquatic Organisms | journal=[[Annual Review of Physiology]] | publisher=[[Annual Reviews (publisher)|Annual Reviews]] | volume=64 | issue=1 | year=2002 | issn=0066-4278 | doi=10.1146/annurev.physiol.64.081501.155802 | pages=223–262| pmid=11826269 }}</ref><ref name="Kishore-Shah-1988">{{cite journal | last1=Kishore | first1=Ganesh M. | last2=Shah | first2=Dilip M. | title=Amino Acid Biosynthesis Inhibitors as Herbicides | journal=[[Annual Review of Biochemistry]] | publisher=[[Annual Reviews (publisher)|Annual Reviews]] | volume=57 | issue=1 | year=1988 | issn=0066-4154 | doi=10.1146/annurev.bi.57.070188.003211 | pages=627–663| pmid=3052285 }}</ref><ref name="Bentley-Haslam-1990">{{cite journal | last1=Bentley | first1=Ronald | last2=Haslam | first2=E. | title=The Shikimate Pathway — A Metabolic Tree with Many Branches | journal=[[Critical Reviews in Biochemistry and Molecular Biology]] | publisher=[[Taylor & Francis]] | volume=25 | issue=5 | year=1990 | issn=1040-9238 | doi=10.3109/10409239009090615 | pages=307–384 | pmid=2279393 | s2cid=1667907}}</ref>

[[File:EPSPreactionII.svg|frameless|upright=3]]

Under normal circumstances, EPSP is [[dephosphorylation|dephosphorylated]] to [[chorismate]], an essential precursor for the amino acids mentioned above.<ref>Purdue University, Department of Horticulture and Landscape Architecture, Metabolic Plant Physiology Lecture notes, [http://www.hort.purdue.edu/rhodcv/hort640c/aromat/ar00007.htm Aromatic amino acid biosynthesis, The shikimate pathway – synthesis of chorismate] {{Webarchive|url=https://web.archive.org/web/20071219165155/http://www.hort.purdue.edu/rhodcv/hort640c/aromat/ar00007.htm |date=December 19, 2007 }}.</ref> These amino acids are used in protein synthesis and to produce secondary metabolites such as [[folate]]s, [[ubiquinone]]s, and [[naphthoquinones|naphthoquinone]].

[[x-ray crystallography|X-ray crystallographic]] studies of glyphosate and EPSPS show that glyphosate functions by occupying the binding site of the phosphoenolpyruvate, mimicking an intermediate state of the ternary enzyme–substrate complex.<ref name="pmid11171958">{{cite journal | vauthors = Schönbrunn E, Eschenburg S, Shuttleworth WA, Schloss JV, Amrhein N, Evans JN, Kabsch W | title = Interaction of the herbicide glyphosate with its target enzyme 5-enolpyruvylshikimate 3-phosphate synthase in atomic detail | journal =[[Proceedings of the National Academy of Sciences of the United States of America]]| volume = 98 | issue = 4 | pages = 1376–80 | date = Feb 2001 | pmid = 11171958 | pmc = 29264 | doi = 10.1073/pnas.98.4.1376 | bibcode = 2001PNAS...98.1376S | doi-access = free }}</ref><ref>[http://www.ebi.ac.uk/pdbe-srv/PDBeXplore/ligand/?ligand=GPJ Glyphosate bound to proteins] in the Protein Data Bank</ref> Glyphosate inhibits the EPSPS enzymes of different species of plants and microbes at different rates.<ref>{{cite journal | last1 = Schulz | first1 = A. | last2 = Krüper | first2 = A. | last3 = Amrhein | first3 = N. | name-list-style = vanc | year = 1985 | title = Differential sensitivity of bacterial 5-enolpyruvylshikimate-3-phosphate synthases to the herbicide glyphosate | journal =[[FEMS Microbiology Letters]]| volume = 28 | issue = 3| pages = 297–301 | doi=10.1111/j.1574-6968.1985.tb00809.x| doi-access = free }}</ref><ref name="Pollegioni_2011">{{cite journal | vauthors = Pollegioni L, Schonbrunn E, Siehl D | title = Molecular basis of glyphosate resistance-different approaches through protein engineering | journal = The FEBS Journal| volume = 278 | issue = 16 | pages = 2753–66 | date = Aug 2011 | pmid = 21668647 | pmc = 3145815 | doi = 10.1111/j.1742-4658.2011.08214.x }}</ref>

==Uses==
[[File:Glyphosate USA 2019.png|thumb|upright=1.5|Second graph is global|alt=Estimated use in the US in 2019 and estimated total use from 1992 to 2019]]
Glyphosate is effective in killing a wide variety of plants, including [[grass]]es and [[Broadleaf weeds|broadleaf]] and [[woody plant]]s. By volume, it is one of the most widely used herbicides.<ref name="NPIC Data Sheet">{{cite web|url=http://npic.orst.edu/factsheets/glyphotech.html|publisher=National Pesticide Information Center|title=Glyphosate technical fact sheet (revised June 2015)|year=2010|access-date=September 1, 2015|archive-url=https://web.archive.org/web/20150828151524/http://npic.orst.edu/factsheets/glyphotech.html|archive-date=August 28, 2015|url-status=bot: unknown}}</ref> In 2007, glyphosate was the most used herbicide in the United States agricultural sector, with 180 to 185 million pounds ({{convert|180000000|to|185000000|lb|t|abbr=off|disp=output only}}) applied, the second-most used in home and garden with 5 to 8 million pounds ({{convert|5000000|to|8000000|lb|t|abbr=off|disp=output only}}) and 13 to 15 million pounds ({{convert|13000000|to|15000000|lb|t|abbr=off|disp=output only}}) in non-agricultural settings.<ref name="EPAusage"/> It is commonly used for [[agriculture]], [[horticulture]], [[viticulture]], and [[silviculture]] purposes, as well as garden maintenance (including home use). It has a relatively small effect on some clover species and [[morning glory]].<ref>{{cite web | first1 = Stevan Z. | last1 = Knezevic | name-list-style = vanc | publisher =[[University of Nebraska Extension]] Integrated Weed Management Specialist | date = February 2010 | url = http://elkhorn.unl.edu/epublic/live/g1484/build/ | archive-url = https://archive.today/20100615033810/http://elkhorn.unl.edu/epublic/live/g1484/build/ | archive-date=June 15, 2010| url-status = dead | title = Use of Herbicide-Tolerant Crops as Part of an Integrated Weed Management Program}}</ref>

[[File:Roundup-in-apple-orchard.jpg|thumb|upright|left|Glyphosate used as an alternative to mowing in an apple orchard in Ciardes, Italy]]
Glyphosate and related herbicides are often used in [[invasive species]] eradication and [[habitat restoration]], especially to enhance [[native plant]] establishment in [[prairie]] ecosystems. The controlled application is usually combined with a selective herbicide and traditional methods of weed eradication such as [[mulch]]ing to achieve an optimal effect.<ref>{{ cite journal | first1 = Priscilla A. | last1 = Nyamai | first2 = Timothy S. | last2 = Prather | first3 =John M. | last3 = Wallace | name-list-style = vanc | year = 2011 | title = Evaluating Restoration Methods across a Range of Plant Communities Dominated by Invasive Annual Grasses to Native Perennial Grasses | journal =[[Invasive Plant Science and Management]]| volume = 4 | issue = 3 | pages = 306–16 | doi = 10.1614/IPSM-D-09-00048.1 | s2cid = 84696972 }}</ref>

In many cities, glyphosate is sprayed along the sidewalks and streets, as well as crevices in between pavement where weeds often grow. However, up to 24% of glyphosate applied to hard surfaces can be run off by water.<ref>{{cite journal |vauthors=Luijendijk CD, Beltman WH, Smidt RA, van der Pas LJ, Kempenaar C | url = http://www.wageningenur.nl/upload_mm/f/d/9/042e8dca-ba43-4687-99f0-fa082db417f1_Nota_353_totaal.pdf | title = Measures to reduce glyphosate runoff from hard surfaces | journal =[[Plant Research International B.V.]]| location = Wageningen | date = May 2005}}</ref> Glyphosate contamination of surface water is attributed to urban and agricultural use.<ref name="pmid19482331">{{cite journal | vauthors = Botta F, Lavison G, Couturier G, Alliot F, Moreau-Guigon E, Fauchon N, Guery B, Chevreuil M, Blanchoud H | title = Transfer of glyphosate and its degradate AMPA to surface waters through urban sewerage systems | journal =[[Chemosphere]]| volume = 77 | issue = 1 | pages = 133–39 | date = Sep 2009 | pmid = 19482331 | doi = 10.1016/j.chemosphere.2009.05.008 | bibcode = 2009Chmsp..77..133B }}</ref> Glyphosate is used to clear [[railroad track]]s and get rid of unwanted aquatic vegetation.<ref name=moneuro/> Since 1994, glyphosate has been used in aerial spraying in Colombia in [[coca eradication]] programs; Colombia announced in May 2015 that by October, it would cease using glyphosate in these programs due to concerns about human toxicity of the chemical.<ref name = BBCColumbia>[[BBC]]. May 10, 2015. [https://www.bbc.com/news/world-latin-america-32677411 Colombia to ban coca spraying herbicide glyphosate]</ref>

Glyphosate is also used for [[crop desiccation]] to increase harvest yield and uniformity.<ref name=moneuro>{{cite web | url = https://monsanto.com/app/uploads/2017/06/agronomic-benefits-of-glyphosate-in-europe.pdf | title = The agronomic benefits of glyphosate in Europe | publisher = [[Monsanto]] Europe SA | date = February 2010 | access-date = 2013-06-02 | archive-date = September 4, 2017 | archive-url = https://web.archive.org/web/20170904155703/https://monsanto.com/app/uploads/2017/06/agronomic-benefits-of-glyphosate-in-europe.pdf | url-status = dead }}</ref> Glyphosate itself is not a chemical [[desiccant]]; rather crop desiccants are so named because application just before harvest kills the crop plants so that the food crop dries from normal environmental conditions ("dry-down") more quickly and evenly.<ref>{{cite web |last1=MacLean |first1=Amy-Jean |title=Desiccant vs. Glyphosate: know your goals |url=https://www.portageonline.com/ag/desiccant-vs-glyphosate-know-your-goals |website=PortageOnline.com |publisher=[[Golden West Broadcasting|Golden West]]|access-date=19 August 2016 |archive-url=https://web.archive.org/web/20190731205820/https://www.portageonline.com/ag/desiccant-vs-glyphosate-know-your-goals |archive-date=31 July 2019 |language=en}}</ref>{{refn|In agriculture, the term desiccant is applied to an agent that promotes dry down. "True desiccants" are not chemical desiccants either, rather the distinction is whether an agent is a contact herbicide such as [[Diquat]] and [[sodium chlorate]] that rapidly kill the above-ground portion of the plant as it dries out over a few days,<ref>{{cite web |title=Crop Desiccation |url=https://saifood.ca/crop-desiccation/ |website=Sustainable Agricultural Innovations & Food |publisher=[[University of Saskatchewan]]|access-date=31 July 2019 |archive-url=https://web.archive.org/web/20190731214944/https://saifood.ca/crop-desiccation/ |archive-date=31 July 2019 |language=en-CA |date=25 October 2016}}</ref> or an agent such as glyphosate that is absorbed systemically and translocated to the root, a process that can take days to weeks.}} Because glyphosate is systemic, excess residue levels can persist in plants due to incorrect application and this may render the crop unfit for sale.<ref>{{cite web|last1=Sprague|first1=Christy|title=Preharvest herbicide applications are an important part of direct-harvest dry bean production| url=http://msue.anr.msu.edu/news/preharvest_herbicide_applications_are_an_important_part_of_direct_harvest_d|website=[[Michigan State University]]|date=August 20, 2015 |publisher=[[Michigan State University Extension]], Department of Plant, Soil and Microbial Sciences|access-date=20 August 2015}}</ref> When applied appropriately, it can promote useful effects.  In sugarcane, for example, glyphosate application increases sucrose concentration before harvest.<ref name="LSUAgExt">{{cite web |last1=Gravois |first1=Kenneth |title=Sugarcane Ripener Recommendations |url=https://www.lsuagcenter.com/topics/crops/sugarcane/harvesting_and_processing/sugarcane-ripener-recommendations--glyphosate |website=[[LSU AgCenter]]|publisher=Louisiana State University, College of Agriculture |archive-url=https://web.archive.org/web/20180920175015/https://www.lsuagcenter.com/topics/crops/sugarcane/harvesting_and_processing/sugarcane-ripener-recommendations--glyphosate |archive-date=20 September 2018 |date=14 August 2017}}</ref> In grain crops (wheat, barley, oats), uniformly dried crops do not have to be [[windrow]]ed (swathed and dried) prior to harvest, but can easily be straight-cut and harvested. This saves the farmer time and money, which is important in northern regions where the growing season is short, and it enhances grain storage when the grain has a lower and more uniform moisture content.<ref name=moneuro/><ref>{{cite web |title=Pre-harvest Management of Small Grains |url=https://blog-crop-news.extension.umn.edu/2017/07/pre-harvest-management-of-small-grains.html |website=Minnesota Crop News |publisher=[[University of Minnesota Extension]]|archive-url=https://web.archive.org/web/20190527142012/https://blog-crop-news.extension.umn.edu/2017/07/pre-harvest-management-of-small-grains.html |archive-date=27 May 2019 |language=en |date=18 July 2017}}</ref><ref>{{cite web |last1=Fowler |first1=D.B. |title=Harvesting, Grain Drying and Storage – Chapter 23 |url=https://www.usask.ca/agriculture/plantsci/winter_cereals/winter-wheat-production-manual/chapter-23.php |website=Winter Wheat Production Manual |publisher=[[University of Saskatchewan]]|archive-url=https://web.archive.org/web/20181209105427/https://www.usask.ca/agriculture/plantsci/winter_cereals/winter-wheat-production-manual/chapter-23.php |archive-date=9 December 2018|language=en|access-date=2017-05-03}}</ref>

===Genetically modified crops===
{{Main|Genetically modified crops|Genetically modified organism|Genetically modified food|Genetically modified food controversies}}
Some micro-organisms have a version of [[5-enolpyruvoyl-shikimate-3-phosphate synthetase]] (EPSPS) resistant to glyphosate inhibition. A version of the enzyme that was both resistant to glyphosate and that was still efficient enough to drive adequate plant growth was identified by Monsanto scientists after much trial and error in an ''[[Agrobacterium]]'' strain called CP4, which was found surviving in a waste-fed column at a glyphosate production facility.<ref name="Pollegioni_2011"/><ref name="Green_2011">{{cite journal | vauthors = Green JM, Owen MD | title = Herbicide-resistant crops: utilities and limitations for herbicide-resistant weed management | journal =[[Journal of Agricultural and Food Chemistry]]| volume = 59 | issue = 11 | pages = 5819–29 | date = Jun 2011 | pmid = 20586458 | pmc = 3105486 | doi = 10.1021/jf101286h }}</ref><ref>{{cite book | vauthors = Rashid A | title = Introduction to Genetic Engineering of Crop Plants: Aims and Achievements | year = 2009 | publisher = I K International | isbn = 978-93-80026-16-9 | pages = 259 }}</ref>{{rp|56}} This ''CP4'' EPSPS gene was [[Molecular cloning|cloned]] and [[Transfection|transfected]] into soybeans. In 1996, genetically modified soybeans were made commercially available.<ref name="urlMonsanto | Company History">{{cite web | url = https://monsanto.com/company/history/ | title = Company History | work = Web Site | publisher = Monsanto Company | access-date = June 27, 2017 | archive-date = November 5, 2018 | archive-url = https://web.archive.org/web/20181105125639/https://monsanto.com/company/history/ | url-status = dead }}</ref> Current glyphosate-resistant crops include soy, [[maize]] (corn), [[canola]], [[alfalfa]], [[sugar beets]], and [[cotton]], with [[wheat]] still under development.

In 2023, 91% of corn, 95% of soybeans, and 94% of cotton produced in the United States were from strains that were genetically modified to be tolerant to multiple herbicides, including [[dicamba]], [[glufosinate]], and glyphosate.<ref name=USDA1>{{cite web|title=Adoption of Genetically Engineered Crops in the U.S.|url=http://www.ers.usda.gov/data-products/adoption-of-genetically-engineered-crops-in-the-us/recent-trends-in-ge-adoption.aspx|website=[[Economic Research Service]]|publisher=USDA|access-date =26 March 2024}}</ref>

==Environmental fate==
[[File:Landscape company Oklahoma.jpg|thumb|[[Landscaping]] company in [[Oklahoma]] applying a weed control product that contains glyphosate]]
Glyphosate has four ionizable sites, with [[pKa]] values of 2.0, 2.6, 5.6 and 10.6.<ref>P. Sprankle, W. F. Meggitt, D. Penner: ''Adsorption, mobility, and microbial degradation of glyphosate in the soil''. In: ''Weed Sci.'' 23(3), p.&nbsp;229–234, as cited in [https://www.inchem.org/documents/ehc/ehc/ehc159.htm Environmental Health Criteria 159].</ref> Therefore, it is a zwitterion in aqueous solutions and is expected to exist almost entirely in zwitterionic forms in the environment. Zwitterions generally adsorb more strongly to soils containing organic carbon and clay than their neutral counterparts.<ref>{{cite web |title = PubChem Compound Summary for CID 3496, Glyphosate | publisher = National Center for Biotechnology Information | access-date = June 16, 2022 | url = https://pubchem.ncbi.nlm.nih.gov/compound/Glyphosate}}</ref> Glyphosate strongly [[Sorption|sorbs]] onto [[soil]] minerals, and, with the exception of [[colloid-facilitated transport]], its soluble residues are expected to be poorly mobile in the free porewater of soils. The spatial extent of [[Groundwater|ground]] and [[surface water]] pollution is therefore considered to be relatively limited.<ref name = "Borggaard_2008" /> Glyphosate is readily degraded by soil microbes to [[aminomethylphosphonic acid]] (AMPA, which like glyphosate strongly adsorbs to soil solids and is thus unlikely to leach to groundwater). Though both glyphosate and AMPA are commonly detected in water bodies, a portion of the AMPA detected may actually be the result of degradation of detergents and other [[aminophosphonate]]s rather than degradation of glyphosate.<ref>{{cite journal | vauthors = Botta F, Lavisonb G, Couturier G, Alliot F, Moreau-Guigon E, Fauchon N, Guery B, Chevreuil M, Blanchoud H | year = 2009 | title = Transfer of glyphosate and its degradate AMPA to surface waters through urban sewerage systems | journal = Chemosphere | volume = 77 | issue = 1| pages = 133–139 | doi=10.1016/j.chemosphere.2009.05.008 | pmid=19482331| bibcode = 2009Chmsp..77..133B}}</ref> The proportion of AMPA from non-glyphosate sources is claimed to be higher in Europe compared to USA.<ref name="u859">{{cite journal | last=Schwientek | first=M. | last2=Rügner | first2=H. | last3=Haderlein | first3=S.B. | last4=Schulz | first4=W. | last5=Wimmer | first5=B. | last6=Engelbart | first6=L. | last7=Bieger | first7=S. | last8=Huhn | first8=C. | title=Glyphosate contamination in European rivers not from herbicide application? | journal=Water Research | volume=263 | date=2024 | doi=10.1016/j.watres.2024.122140 | page=122140}}</ref> Glyphosate does have the potential to contaminate surface waters due to its aquatic use patterns and through erosion, as it adsorbs to [[colloid]]al soil particles suspended in [[Surface runoff|runoff]]. Detection in surface waters (particularly downstream from agricultural uses) has been reported as both broad and frequent by the [[United States Geological Survey]] (USGS) researchers,<ref>{{cite journal |last1=Battaglin |first1=W.A. |last2=Meyer |first2=M.T. |last3=Kuivila |first3=K.M. |last4=Dietze |first4=J.E. |title=Glyphosate and Its Degradation Product AMPA Occur Frequently and Widely in U.S. Soils, Surface Water, Groundwater, and Precipitation |journal=JAWRA Journal of the American Water Resources Association |date=April 2014 |volume=50 |issue=2 |pages=275–90 |doi=10.1111/jawr.12159|bibcode=2014JAWRA..50..275B |s2cid=15865832 }}</ref> although other similar research found equal frequencies of detection in urban-dominated small streams.<ref>{{cite journal |last1=Mahler |first1=Barbara J. |last2=Van Metre |first2=Peter C. |last3=Burley |first3=Thomas E. |last4=Loftin |first4=Keith A. |last5=Meyer |first5=Michael T. |last6=Nowell |first6=Lisa H. |title=Similarities and differences in occurrence and temporal fluctuations in glyphosate and atrazine in small Midwestern streams (USA) during the 2013 growing season |journal=Science of the Total Environment |date=February 2017 |volume=579 |pages=149–58 |doi=10.1016/j.scitotenv.2016.10.236|pmid=27863869 |bibcode=2017ScTEn.579..149M |doi-access=free }}</ref> Rain events can trigger dissolved glyphosate loss in transport-prone soils.<ref>{{cite journal |last1=Richards |first1=Brian K. |last2=Pacenka |first2=Steven |last3=Meyer |first3=Michael T. |last4=Dietze |first4=Julie E. |last5=Schatz |first5=Anna L. |last6=Teuffer |first6=Karin |last7=Aristilde |first7=Ludmilla |last8=Steenhuis |first8=Tammo S. |title=Antecedent and Post-Application Rain Events Trigger Glyphosate Transport from Runoff-Prone Soils |journal=Environmental Science & Technology Letters |date=23 April 2018 |volume=5 |issue=5 |pages=249–54 |doi=10.1021/acs.estlett.8b00085|bibcode=2018EnSTL...5..249R }}</ref> The mechanism of glyphosate sorption to soil is similar to that of [[phosphate]] fertilizers, the presence of which can reduce glyphosate sorption.<ref>{{cite journal | vauthors = Muniraa S, Farenhorsta A, Flatena D, Grant C | year = 2016 | title = Phosphate fertilizer impacts on glyphosate sorption by soil | journal = Chemosphere | volume = 153 | pages = 471–77 | doi=10.1016/j.chemosphere.2016.03.028| pmid = 27035384 | bibcode = 2016Chmsp.153..471M| hdl = 1993/31877 | hdl-access = free }}</ref> Phosphate fertilizers are subject to release from sediments into water bodies under [[:wikt:anaerobic|anaerobic]] conditions, and similar release can also occur with glyphosate, though significant impact of glyphosate release from sediments has not been established.<ref>{{cite journal | vauthors = Kanissery RG, Welsh A, Sims GK | s2cid = 31227173 | year = 2014 | title = Effect of soil aeration and phosphate addition on the microbial bioavailability of 14C-glyphosate | journal = Journal of Environmental Quality| volume = 44 | issue = 1| pages = 137–44 | doi = 10.2134/jeq2014.08.0331 | pmid = 25602328 }}</ref> Limited leaching can occur after high rainfall after application. If glyphosate reaches surface water, it is not broken down readily by water or sunlight.<ref name="epa_reds"/><ref name = "Borggaard_2008">{{cite journal | vauthors = Borggaard OK, Gimsing AL | title = Fate of glyphosate in soil and the possibility of leaching to ground and surface waters: a review | journal = Pest Management Science | volume = 64 | issue = 4 | pages = 441–56 | date = Apr 2008 | doi = 10.1002/ps.1512 | pmid = 18161065 | doi-access = free }}</ref>

The [[half-life]] of glyphosate in soil ranges between 2 and 197 days; a typical field half-life of 47 days has been suggested. Soil and climate conditions affect glyphosate's persistence in soil. The median half-life of glyphosate in water varies from a few to 91 days.<ref name="NPIC Data Sheet"/> At a site in Texas, half-life was as little as three days. A site in Iowa had a half-life of 141.9 days.<ref name=Giesy2000 /> The glyphosate metabolite AMPA has been found in Swedish forest soils up to two years after a glyphosate application. In this case, the persistence of AMPA was attributed to the soil being frozen for most of the year.<ref name="pmid2806176">{{cite journal | vauthors = Torstensson NT, Lundgren LN, Stenström J | title = Influence of climatic and edaphic factors on persistence of glyphosate and 2,4-D in forest soils | journal = Ecotoxicology and Environmental Safety | volume = 18 | issue = 2 | pages = 230–39 | date = Oct 1989 | pmid = 2806176 | doi = 10.1016/0147-6513(89)90084-5 | bibcode = 1989EcoES..18..230T }}</ref> Glyphosate adsorption to soil, and later release from soil, varies depending on the kind of soil.<ref name="pmid19447533">{{cite journal | vauthors = Albers CN, Banta GT, Hansen PE, Jacobsen OS | title = The influence of organic matter on sorption and fate of glyphosate in soil--comparing different soils and humic substances | journal = Environmental Pollution | volume = 157 | issue = 10 | pages = 2865–70 | date = Oct 2009 | pmid = 19447533 | doi = 10.1016/j.envpol.2009.04.004 | bibcode = 2009EPoll.157.2865A }}</ref><ref>{{cite journal | url = http://www.academyjournal.net/asj/index.php/TSPN/article/viewArticle/193 | title = Does phosphate affect soil sorption and degradation of glyphosate? – A review | vauthors = Ole K, Borggaard OK | journal = Trends in Soil Science and Plant Nutrition | volume = 2 | issue = 1 | year = 2011 | pages = 17–27 }}{{Dead link|date=December 2019 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> Glyphosate is generally less persistent in water than in soil, with 12- to 60-day persistence observed in Canadian ponds, although persistence of over a year has been recorded in the sediments of American ponds.<ref name="epa_reds"/> The half-life of glyphosate in water is between 12 days and 10 weeks.<ref name="Sparling">{{cite journal | vauthors = Sparling DW, Matson C, Bickham J, Doelling-Brown P | year = 2006 | title = Toxicity of glyphosate as Glypro® and LI700 to red-eared slider (''Trachemys scripta elegans'') embryos and early hatchlings | journal = Environmental Toxicology and Chemistry | volume = 25 | issue = 10 | pages = 2768–74 | doi = 10.1897/05-152.1 | pmid = 17022419 | s2cid = 12954689 }}</ref>

===Residues in food products===
According to the [[National Pesticide Information Center]] fact sheet, glyphosate is not included in compounds tested for by the Food and Drug Administration's Pesticide Residue Monitoring Program, nor in the United States Department of Agriculture's Pesticide Data Program.<ref name="NPIC Data Sheet"/> The U.S. has determined the [[acceptable daily intake]] of glyphosate at 1.75 milligrams per kilogram of body weight per day (mg/kg/bw/day) while the European Union has set it at 0.5.<ref>{{cite web | last = European Commission| date = 2017 | url = http://ec.europa.eu/food/plant/pesticides/eu-pesticides-database/public/?event=activesubstance.detail&language=EN&selectedID=1438 | title = EU Pesticides database: Glyphosate| access-date = 29 August 2018}}</ref>

Pesticide residue controls carried out by EU Member States in 2016 analysed 6,761 samples of food products for glyphosate residues. 3.6% of the samples contained [[limit of quantification|quantifiable]] glyphosate residue levels with 19 samples (0.28%) exceeding the European [[Maximum residue limit|maximum residue levels]] (MRLs), which included six samples of honey and other apicultural products (MRL = 0.05&nbsp;mg/kg) and eleven samples of buckwheat and other pseudo‐cereals (MRL = 0.1&nbsp;mg/kg). Glyphosate residues below the European MRLs were most frequently found in dry lentils, linseeds, soya beans, dry peas, tea, buckwheat, barley, wheat and rye.<ref name="ESFA2018residues">{{cite journal |last1=European Food Safety Authority |title=The 2016 European Union report on pesticide residues in food |journal= EFSA Journal|date=July 2018 |volume=16 |issue=7 |page=67 |doi=10.2903/j.efsa.2018.5348 |pmid=32625983 |pmc=7009629 |doi-access=free }}</ref> In Canada, a survey of 7,955 samples of food found that 42.3% contained detectable quantities of glyphosate and only 0.6% contained a level higher than the Canadian MRL of 0.1&nbsp;mg/kg for most foods and 4&nbsp;mg/kg for beans and chickpeas. Of the products that exceeded MRLs, one third were organic products. [[Health Canada]] concluded based on the analysis "that there was no long-term health risk to Canadian consumers from exposure to the levels of glyphosate".<ref>{{cite journal |last1=Kolakowski |first1=Beata M. |last2=Miller |first2=Leigh |last3=Murray |first3=Angela |last4=Leclair |first4=Andrea |last5=Bietlot |first5=Henri |last6=van de Riet |first6=Jeffrey M. |title=Analysis of Glyphosate Residues in Foods from the Canadian Retail Markets between 2015 and 2017 |journal=Journal of Agricultural and Food Chemistry |date=6 May 2020 |volume=68 |issue=18 |pages=5201–5211 |doi=10.1021/acs.jafc.9b07819|pmid=32267686 |doi-access=free }}</ref>

==Toxicity==
Glyphosate is the active ingredient in herbicide formulations containing it. However, in addition to glyphosate salts, commercial formulations of glyphosate contain additives (known as adjuvants) such as [[surfactant]]s, which vary in nature and concentration. Surfactants such as [[polyethoxylated tallow amine]] (POEA) are added to glyphosate to enable it to wet the leaves and penetrate the [[plant cuticle|cuticle]] of the plants.

===Glyphosate alone===
====Humans====
The acute oral toxicity for mammals is low,<ref name="pmid29117584">{{cite journal | vauthors = Van Bruggen AC, He MM, Shin K, Mai V, Jeong KC, Finckh MR, Morris JG | title = Environmental and health effects of the herbicide glyphosate | journal = Sci. Total Environ. | volume = 616–17 | pages = 255–68 | date = March 2018 | pmid = 29117584 | doi = 10.1016/j.scitotenv.2017.10.309 | bibcode = 2018ScTEn.616..255V }}</ref> but death has been reported after deliberate overdose of [[Dose–response relationship|concentrated]] formulations.<ref name="pmid22835958">{{cite journal |vauthors= Sribanditmongkol P, Jutavijittum P, Pongraveevongsa P, Wunnapuk K, Durongkadech P |title= Pathological and toxicological findings in glyphosate-surfactant herbicide fatality: a case report |journal= The American Journal of Forensic Medicine and Pathology |volume= 33 |issue=3 |pages= 234–37 |date= Sep 2012 |doi= 10.1097/PAF.0b013e31824b936c |pmid= 22835958 |s2cid= 3457850 }}</ref> The surfactants in glyphosate formulations can increase the relative acute toxicity of the formulation.<ref name="Bradberry_2004">{{cite journal |vauthors= Bradberry SM, Proudfoot AT, Vale JA |s2cid= 5636017 |title= Glyphosate poisoning |journal = Toxicological Reviews |volume= 23 |issue=3 |pages= 159–67 |year= 2004 |pmid= 15862083 |doi= 10.2165/00139709-200423030-00003}}</ref><ref name=SERA2003>{{Citation| title = Glyphosate: Human Health and Ecological Risk Assessment | publisher= Syracuse Environmental Research Associates, Inc.(SERA) |access-date = 2018-08-20| url = https://www.fs.fed.us/r5/hfqlg/publications/herbicide_info/2003_glyphosate.pdf}}</ref> Glyphosate is less toxic than 94% of herbicides, and is also less toxic than household chemicals such as [[table salt]] or [[vinegar]].<ref name="PennStateExt">{{cite web |last1=Wallace |first1=John |last2=Lingenfelter |first2=Dwight |title=Glyphosate (Roundup): Understanding Risks to Human Health |url=https://extension.psu.edu/glyphosate-roundup-understanding-risks-to-human-health |website=extension.psu.edu |publisher=Pennsylvania State University Extension |access-date=12 July 2024 |language=en}}</ref>

In a 2017 risk assessment, the European Chemicals Agency (ECHA) wrote: "There is very limited information on skin irritation in humans. Where skin irritation has been reported, it is unclear whether it is related to glyphosate or co-formulants in glyphosate-containing herbicide formulations." The ECHA concluded that available human data was insufficient to support classification for skin corrosion or irritation.<ref>{{Cite web|url=https://echa.europa.eu/documents/10162/2f8b5c7f-030f-5d3a-e87e-0262fb392f38|title=Committee of Risk Assessment Opinion proposing harmonised classification and labelling at EU level of glyphosate (ISO); N-(phosphonomethyl)glycine}}</ref> Inhalation is a minor route of exposure, but spray mist may cause oral or nasal discomfort, an unpleasant taste in the mouth, or tingling and irritation in the throat. Eye exposure may lead to mild conjunctivitis. Superficial corneal injury is possible if irrigation is delayed or inadequate.<ref name="Bradberry_2004"/>

====Cancer====
The [[scientific consensus|consensus]] among national pesticide regulatory agencies and scientific organizations is that labeled uses of glyphosate have demonstrated no evidence of human carcinogenicity.<ref name=Tarazona/> The Joint FAO/WHO Meeting on Pesticide Residues (JMPR),<ref name="JMPR2016">{{cite book |last1=Boobis |first1=Alan R. |title=Pesticide residues in food 2016, Joint FAO/WHO Meeting on Pesticide Residues, 9–13 May 2016 |date=2016 |publisher=WHO/FAO |location=Rome |isbn=978-92-5-109246-0 |pages=19–28 |url=https://www.who.int/foodsafety/areas_work/chemical-risks/JMPR_2016_Report_May.pdf}}</ref> the [[European Commission]], the Canadian [[Pest Management Regulatory Agency]], the [[Australian Pesticides and Veterinary Medicines Authority]]<ref>{{Cite book| publisher = SAGE Publications, Inc.| isbn = 978-1-4129-6987-1| last1 = Guston| first1 = David| last2 = Ludlow| first2 = Karinne| title = Encyclopedia of Nanoscience and Society| chapter = Australian Pesticides and Veterinary Medicines Authority| location =  Thousand Oaks, CA| date = 2010| chapter-url = http://sk.sagepub.com/reference/nanoscience/n22.xml}}</ref> and the German [[Federal Institute for Risk Assessment]]<ref>{{Cite web| title = The BfR has finalised its draft report for the re-evaluation of glyphosate – BfR| access-date = 2018-08-18| url = https://www.bfr.bund.de/en/the_bfr_has_finalised_its_draft_report_for_the_re_evaluation_of_glyphosate-188632.html}}</ref> have concluded that there is no evidence that glyphosate poses a carcinogenic or [[genotoxic]] risk to humans. The [[United States Environmental Protection Agency]] (EPA) has classified glyphosate as "not likely to be carcinogenic to humans."<ref>{{Cite web| last = US EPA| first = OCSPP| title = EPA Releases Draft Risk Assessments for Glyphosate| work = US EPA| format = Announcements and Schedules| access-date = 2018-08-18| date = 2017-12-18| url = https://www.epa.gov/pesticides/epa-releases-draft-risk-assessments-glyphosate}}</ref><ref name="CARC2015">{{cite book |last1=Cancer Assessment Review Committee, HED, Office of Pesticides Program, US EPA |title=Evaluation of the Carcinogenic potential of Glyphosate, Final Report |date=October 1, 2015 |publisher=US EPA |location=Washington |pages=77–78 |url=http://src.bna.com/eAi}}</ref> One international scientific organization, the [[International Agency for Research on Cancer]], classified glyphosate in [[List of IARC Group 2A carcinogens|Group 2A]], "probably carcinogenic to humans" in 2015.<ref name="iarcmono"/><ref name="Lancet20March2015"/>

{{As of|2020}}, the evidence for long-term exposure to glyphosate increasing the risk of human cancer remains inconclusive.<ref>{{cite journal|vauthors = Agostini LP, Dettogni RS, Dos Reis RS, Stur E, Dos Santos E, Ventorim DP, Garcia FM, Cardoso RC, Graceli JB, Louro ID|title= Effects of glyphosate exposure on human health: Insights from epidemiological and in vitro studies|url=https://pubmed.ncbi.nlm.nih.gov/31972943/|journal=Sci Total Environ|volume=705|page=135808|date=2020|doi= 10.1016/j.scitotenv.2019.135808|pmid= 31972943|bibcode= 2020ScTEn.70535808A|s2cid= 210883035}}</ref> There is weak evidence human cancer risk might increase as a result of occupational exposure to large amounts of glyphosate, such as in agricultural work, but no good evidence of such a risk from home use, such as in domestic gardening.<ref name=cruk>{{cite web |publisher=Cancer Research UK| title=Food Controversies&nbsp;– Pesticides and organic foods|url=http://www.cancerresearchuk.org/about-cancer/causes-of-cancer/diet-and-cancer/food-controversies#food_controversies4 |date=2016 |access-date=28 November 2017}}</ref><ref>{{cite journal|vauthors=Donato F, Pira E, Ciocan C, Boffetta P|title=Exposure to glyphosate and risk of non-Hodgkin lymphoma and multiple myeloma: an updated meta-analysis|journal=Med Lav|volume=111|pages=63–73|date=2020|issue=1|pmid=32096774|pmc=7809965}}</ref>

Although some small studies have suggested an association between glyphosate and [[non-hodgkin lymphoma]], subsequent work confirmed the likelihood this work suffered from bias, and the association could not be demonstrated in more robust studies.<ref name=boff>{{cite journal |vauthors=Boffetta P, Ciocan C, Zunarelli C, Pira E |title=Exposure to glyphosate and risk of non-Hodgkin lymphoma: an updated meta-analysis |journal=Med Lav |volume=112 |issue=3 |pages=194–199 |date=June 2021 |pmid=34142676 |pmc=8223940 |doi=10.23749/mdl.v112i3.11123 |type=Meta-analysis}}</ref><ref name="EFSA2023">{{cite journal |vauthors=Álvarez F, Arena M, Auteri D, Binaglia M, Castoldi AF, Chiusolo A, Crivellente F, Egsmose M, Fait G, Ferilli F, Gouliarmou V, Nogareda LH, Ippolito A, Istace F, Jarrah S, Kardassi D, Kienzler A, Lanzoni A, Lava R, Linguadoca A, Lythgo C, Mangas I, Padovani L, Panzarea M, Parra Morte JM, Rizzuto S, Romac A, Rortais A, Serafimova R, Sharp R, Szentes C, Terron A, Theobald A, Tiramani M, Vianello G, Villamar-Bouza L |title=Peer review of the pesticide risk assessment of the active substance glyphosate |journal=EFSA J |volume=21 |issue=7 |pages=e08164 |date=July 2023 |pmid=37502013 |pmc=10369247 |doi=10.2903/j.efsa.2023.8164 |type=Review |display-authors=5}}</ref><ref>{{Cite web |date=2023-08-25 |orig-date= |title=Peer Review Report on Glyphosate (AIR V) Part 3 of 6: Report of Pesticide Peer Review TC 80 |url=https://open.efsa.europa.eu/study-inventory/EFSA-Q-2020-00140 |archive-format= |access-date=2023-11-16 |pages=59–78 |language=en |publication-place=EFSA|quote= The available epidemiological studies currently do not provide sufficient indication that glyphosate exposure is associated with any cancer-related health effect.}}</ref>

====Other mammals====
Amongst mammals, glyphosate is considered to have "low to very low toxicity". The [[LD50|LD<sub>50</sub>]] of glyphosate is 5,000&nbsp;mg/kg for rats, 10,000&nbsp;mg/kg in mice and 3,530&nbsp;mg/kg in goats. The acute dermal LD<sub>50</sub> in rabbits is greater than 2,000&nbsp;mg/kg. Indications of glyphosate toxicity in animals typically appear within 30 to 120 minutes following ingestion of a large enough dose, and include initial excitability and [[tachycardia]], [[ataxia]], depression, and [[bradycardia]], although severe toxicity can develop into collapse and convulsions.<ref name="NPIC Data Sheet"/>

A review of unpublished short-term rabbit-feeding studies reported severe toxicity effects at 150&nbsp;mg/kg/day and "[[NOAEL|no observed adverse effect level]]" doses ranging from 50 to 200&nbsp;mg/kg/day.<ref name="pmid23286529">{{cite journal | vauthors = Kimmel GL, Kimmel CA, Williams AL, DeSesso JM | title = Evaluation of developmental toxicity studies of glyphosate with attention to cardiovascular development | journal = Critical Reviews in Toxicology | volume = 43 | issue = 2 | pages = 79–95 | year = 2013 | pmid = 23286529 | pmc = 3581053 | doi = 10.3109/10408444.2012.749834 }}</ref> Glyphosate can have carcinogenic effects in nonhuman mammals. These include the induction of positive trends in the incidence of [[Kidney cancer|renal tubule carcinoma]] and [[haemangiosarcoma]] in male mice, and increased [[Pancreatic cancer|pancreatic islet-cell adenoma]] in male rats.<ref name="Lancet20March2015" /> In reproductive toxicity studies performed in rats and rabbits, no adverse maternal or offspring effects were seen at doses below 175–293&nbsp;mg/kg/day.<ref name="NPIC Data Sheet"/>

Large quantities of glyphosate-based herbicides may cause life-threatening [[arrhythmia]]s in mammals. Evidence also shows that such herbicides cause direct electrophysiological changes in the cardiovascular systems of rats and rabbits.<ref>{{cite journal | vauthors = Gress S, Lemoine S, Séralini GE, Puddu PE | s2cid = 17936407 | title = Glyphosate-based herbicides potently affect cardiovascular system in mammals: review of the literature | journal = Cardiovascular Toxicology | volume = 15 | issue = 2 | pages = 117–26 | date = April 2015 | pmid = 25245870 | doi = 10.1007/s12012-014-9282-y }}</ref>

====Aquatic fauna====
In many freshwater invertebrates, glyphosate has a 48-hour [[LC50|LC<sub>50</sub>]] ranging from 55 to 780 ppm. The 96-hour LC<sub>50</sub> is 281 ppm for [[grass shrimp]] (''Palaemonetas vulgaris'') and 934 ppm for [[fiddler crabs]] (''Uca pagilator''). These values make glyphosate "slightly toxic to practically non-toxic".<ref name="NPIC Data Sheet"/>

====Antimicrobial activity====
The [[antimicrobial]] activity of glyphosate has been described in the microbiology literature since its discovery in 1970 and the description of glyphosate's mechanism of action in 1972. Efficacy was described for numerous bacteria and fungi.<ref>Abraham William Wildwood. [http://www.patentbuddy.com/Patent/7771736 Glyphosate formulations and their use for inhibition of 5-enolpyrovylshikimate-3-phosphate synthase], US Patent 7, 771, 736 B2; 2010</ref> Glyphosate can control the growth of [[apicomplexa]]n parasites, such as ''[[Toxoplasma gondii]]'', ''[[Plasmodium falciparum]]'' (malaria), and ''[[Cryptosporidium parvum]]'', and has been considered an antimicrobial agent in mammals.<ref name="pmid11865437">{{cite journal | vauthors = Roberts CW, Roberts F, Lyons RE, Kirisits MJ, Mui EJ, Finnerty J, Johnson JJ, Ferguson DJ, Coggins JR, Krell T, Coombs GH, Milhous WK, Kyle DE, Tzipori S, Barnwell J, Dame JB, Carlton J, McLeod R | title = The shikimate pathway and its branches in apicomplexan parasites | journal = The Journal of Infectious Diseases | volume = 185 | issue = Suppl 1 | pages = S25–36 | date = Feb 2002 | pmid = 11865437 | doi = 10.1086/338004 | doi-access = free }}</ref> Inhibition can occur with some [[Rhizobium]] species important for soybean nitrogen fixation, especially under moisture stress.<ref name="pmid15224916">{{cite journal | vauthors = Zablotowicz RM, Reddy KN | title = Impact of glyphosate on the Bradyrhizobium japonicum symbiosis with glyphosate-resistant transgenic soybean: a minireview | journal = Journal of Environmental Quality | volume = 33 | issue = 3 | pages = 825–31 | year = 2004 | pmid = 15224916 | doi = 10.2134/jeq2004.0825 | bibcode = 2004JEnvQ..33..825Z }}</ref>

====Soil biota====
[[File:Glyphosate degradation.svg|thumb|upright=1.5|Degradation pathway of glyphosate in the ground<ref name=Giesy2000/>]]
When glyphosate comes into contact with the soil, it can be bound to [[soil texture|soil particles]], thereby slowing its degradation.<ref name="epa_reds"/><ref name=Andrea>{{cite journal | title = Influence of repeated applications of glyphosate on its persistence and soil bioactivity | year = 2003 | vauthors = Andréa MM, Peres TB, Luchini LC, Bazarin S, Papini S, Matallo MB, Savoy VL | journal = Pesquisa Agropecuária Brasileira | volume = 38 | issue = 11 | pages = 1329–35 | doi = 10.1590/S0100-204X2003001100012 | doi-access = free }}</ref> Glyphosate and its degradation product, [[aminomethylphosphonic acid]] are considered to be much more benign toxicologically and environmentally than most of the herbicides replaced by glyphosate.<ref>{{cite journal | vauthors = Cerdeira AL, Duke SO | title = Effects of glyphosate-resistant crop cultivation on soil and water quality | journal = GM Crops | volume = 1 | issue = 1 | pages = 16–24 | date = January 2010 | pmid = 21912208 | doi = 10.4161/gmcr.1.1.9404 | s2cid = 38119904 | url = http://ainfo.cnptia.embrapa.br/digital/bitstream/item/47350/1/2010AP03-2.pdf }}</ref> A 2016 meta-analysis concluded that at typical application rates glyphosate had no effect on soil microbial biomass or respiration.<ref name="NguyenRose2016">{{cite journal | last1 = Nguyen | first1 = Duy B. | last2 = Rose | first2 = Michael T. | last3 = Rose | first3 = Terry J. | last4 = Morris | first4 = Stephen G. | last5 = van Zwieten | first5 = Lukas | name-list-style = vanc | title = Impact of glyphosate on soil microbial biomass and respiration: A meta-analysis | journal = Soil Biology and Biochemistry | volume = 92 | year = 2016| pages = 50–57 | issn = 0038-0717 | doi = 10.1016/j.soilbio.2015.09.014 | bibcode = 2016SBiBi..92...50N }}</ref> A 2016 review noted that contrasting effects of glyphosate on earthworms have been found in different experiments with some species unaffected, but others losing weight or avoiding treated soil. Further research is required to determine the impact of glyphosate on earthworms in complex ecosystems.<ref name="RoseCavagnaro2016">{{cite book |last1=Rose|first1=Michael T. |last2=Cavagnaro |first2=Timothy R. |last3=Scanlan |first3=Craig A. |last4=Rose |first4=Terry J.|last5=Vancov |first5=Tony |last6=Kimber |first6=Stephen |last7=Kennedy |first7=Ivan R. |last8=Kookana |first8=Rai S. |last9=Van Zwieten |first9=Lukas |series=Advances in Agronomy | name-list-style = vanc |title=Impact of Herbicides on Soil Biology and Function |volume=136 |year=2016 |pages=168 |doi=10.1016/bs.agron.2015.11.005 |hdl=2440/110451 |isbn=978-0128046814}}</ref>

====Endocrine disruption====
In 2007, the EPA selected glyphosate for further screening through its Endocrine Disruptor Screening Program (EDSP). Selection for this program is based on a compound's prevalence of use and does not imply particular suspicion of [[endocrine]] activity.<ref>{{cite journal | author = United States Environmental Protection Agency | journal = Federal Register | volume = 72 | issue = 116 | pages = 33486–503 | date = 18 June 2007 | title = Draft List of Initial Pesticide Active Ingredients and Pesticide Inerts to be Considered for Screening under the Federal Food, Drug, and Cosmetic Act | url = http://www.epa.gov/endo/pubs/draft_list_frn_061807.pdf }}</ref> On June 29, 2015, the EPA released the Weight of Evidence Conclusions of the EDSP Tier 1 screening for glyphosate, recommending that glyphosate not be considered for Tier 2 testing. The Weight of Evidence conclusion stated "...there was no convincing evidence of potential interaction with the [[estrogen]], [[androgen]] or [[thyroid]] pathways."<ref>{{cite web |author= United States Environmental Protection Agency |title= Memorandum: EDSP Weight of Evidence Conclusions on the Tier 1 Screening Assays for the List 1 Chemicals |url= http://www2.epa.gov/sites/production/files/2015-06/documents/glyphosate-417300_2015-06-29_txr0057175.pdf |archive-url= https://web.archive.org/web/20160116111524/http://www.epa.gov/sites/production/files/2015-06/documents/glyphosate-417300_2015-06-29_txr0057175.pdf |archive-date= 16 January 2016 |date= 29 June 2015 }}</ref> A review of the evidence by the European Food Safety Authority published in September 2017 showed conclusions similar to those of the EPA report.<ref>{{cite journal |title=Peer review of the pesticide risk assessment of the potential endocrine disrupting properties of glyphosate |journal= EFSA Journal|date=September 2017 |volume=15 |issue=9 |doi=10.2903/j.efsa.2017.4979|pmid= 32625644|doi-access=free |author1= European Food Safety Authority |pages= e04979|pmc= 7010201}}</ref>

====Effect on plant health====
Some studies have found causal relationships between glyphosate and increased or decreased disease resistance.<ref>{{cite book |doi=10.1007/978-1-4020-5799-1_15 |chapter=Interactions of Synthetic Herbicides with Plant Disease and Microbial Herbicides |title=Novel Biotechnologies for Biocontrol Agent Enhancement and Management |series=NATO Security through Science Series |year=2007 | vauthors = Duke SO, Wedge DE, Cerdeira AL, Matallo MB | isbn = 978-1-4020-5797-7 | pages = 277–96 |publisher=Springer |location=Dordrecht | editor1-first = Maurizio | editor1-last = Vurro | editor2-first = Jonathan | editor2-last = Gressel }}</ref> Exposure to glyphosate has been shown to change the species composition of [[Endophyte|endophytic bacteria]] in plant hosts, which is highly variable.<ref>{{cite journal | vauthors = Rosenblueth M, Martínez-Romero E | title = Bacterial endophytes and their interactions with hosts | journal = Molecular Plant-Microbe Interactions | volume = 19 | issue = 8 | pages = 827–37 | date = Aug 2006 | pmid = 16903349 | doi = 10.1094/MPMI-19-0827 | doi-access = free }}</ref>

===Glyphosate-based formulations===
Glyphosate-based formulations may contain a number of [[Agricultural spray adjuvant|adjuvants]], the identities of which may be proprietary.<ref name="www2.epa.gov">{{cite web |url=http://www2.epa.gov/pesticide-registration/pesticide-registration-manual |title=Pesticide Registration Manual &#124; Pesticide Registration &#124; US EPA |date=March 4, 2013 |access-date=March 7, 2014 |archive-date=April 14, 2016 |archive-url=https://web.archive.org/web/20160414065403/https://www.epa.gov/pesticide-registration/pesticide-registration-manual |url-status=dead }}</ref> Surfactants are used in herbicide formulations as [[wetting]] agents, to maximize coverage and aid penetration of the herbicide(s) through plant leaves. As agricultural spray adjuvants, surfactants may be pre-mixed into commercial formulations or they may be purchased separately and mixed on-site.<ref>{{cite web |title=Adjuvants for Enhancing Herbicide Performance |url=https://extension.psu.edu/adjuvants-for-enhancing-herbicide-performance |website=extension.psu.edu |publisher=Penn State Extension |access-date=15 August 2018 |language=en}}</ref>

[[Polyethoxylated tallow amine]] (POEA) is a surfactant used in the original Roundup formulation and was commonly used in 2015.<ref name=usgs.glyphosate.poea>{{cite web|title=Measuring POEA, a Surfactant Mixture in Herbicide Formulations|url=http://toxics.usgs.gov/highlights/glyphosate_poea.html|publisher=U.S. Geological Survey|access-date=May 29, 2015|archive-date=October 7, 2015|archive-url=https://web.archive.org/web/20151007051906/http://toxics.usgs.gov/highlights/glyphosate_poea.html|url-status=dead}}</ref> Different versions of Roundup have included different percentages of POEA. A 1997 US government report said that Roundup is 15% POEA while Roundup Pro is 14.5%.<ref name="fs.fed.us"/> Since POEA is more toxic to fish and amphibians than glyphosate alone, POEA is not allowed in aquatic formulations.<ref name="Langeland"/><ref name="fs.fed.us">Gary L. Diamond and Patrick R. Durkin February 6, 1997, under contract from the United States Department of Agriculture. [http://www.fs.fed.us/foresthealth/pesticide/pdfs/Surfactants.pdf Effects of Surfactants on the Toxicity of Glyphosate, with Specific Reference to RODEO]</ref><ref name=Mann/> A 2000 review of the ecotoxicological data on Roundup shows at least 58 studies exist on the effects of Roundup on a range of organisms.<ref name=Giesy2000>{{cite book |doi=10.1007/978-1-4612-1156-3_2 |year=2000 | vauthors = Giesy JP, Dobson S, Solomon KR |chapter=Ecotoxicological Risk Assessment for Roundup® Herbicide | isbn = 978-0-387-95102-7 | volume = 167 | pages = 35–120 | chapter-url = https://books.google.com/books?id=7iTdm5ii4NYC&pg=PA35|title=Reviews of Environmental Contamination and Toxicology |publisher=Springer |location=New York, NY }}</ref> This review concluded that "...for terrestrial uses of Roundup minimal acute and chronic risk was predicted for potentially exposed non-target organisms".<ref>{{cite web |title=Ecotoxicological Risk Assessment for Roundup Herbicide |url=https://www.usask.ca/toxicology/jgiesy/pdf/publications/JA-228.pdf |access-date=May 9, 2019 |archive-date=August 7, 2019 |archive-url=https://web.archive.org/web/20190807140955/https://www.usask.ca/toxicology/jgiesy/pdf/publications/JA-228.pdf |url-status=dead }}</ref>

====Human====

Overall, there is no conclusive evidence on glyphosate's effect on human health.<ref>{{cite journal |vauthors=Gillezeau C, van Gerwen M, Shaffer RM, Rana I, Zhang L, Sheppard L, Taioli E |title=The evidence of human exposure to glyphosate: a review |journal=Environ Health |volume=18 |issue=1 |pages=2 |date=January 2019 |pmid=30612564 |pmc=6322310 |doi=10.1186/s12940-018-0435-5 |bibcode=2019EnvHe..18....2G |type=Review |doi-access=free }}</ref><ref>{{cite journal |vauthors=Peillex C, Pelletier M |title=The impact and toxicity of glyphosate and glyphosate-based herbicides on health and immunity |journal=J Immunotoxicol |volume=17 |issue=1 |pages=163–174 |date=December 2020 |pmid=32897110 |doi=10.1080/1547691X.2020.1804492 |s2cid=221541734 |url=|doi-access=free |hdl=20.500.11794/66510 |hdl-access=free }}</ref>

[[Acute toxicity]] and [[chronic toxicity]] are dose-related. Skin exposure to ready-to-use concentrated glyphosate formulations can cause irritation, and [[Contact dermatitis#Photocontact dermatitis|photocontact dermatitis]] has been occasionally reported. These effects are probably due to the preservative [[benzisothiazolin-3-one]]. Severe skin burns are very rare.<ref name="Bradberry_2004" /> Inhalation is a minor route of exposure, but spray mist may cause oral or nasal discomfort, an unpleasant taste in the mouth, or tingling and irritation in the throat. Eye exposure may lead to mild conjunctivitis. Superficial corneal injury is possible if irrigation is delayed or inadequate.<ref name="Bradberry_2004" /> Death has been reported after deliberate overdose.<ref name="Bradberry_2004"/><ref name="pmid22835958"/> Ingestion of Roundup ranging from 85 to 200 ml (of 41% solution) has resulted in death within hours of ingestion, although it has also been ingested in quantities as large as 500 ml with only mild or moderate symptoms.<ref name="pmid1673618">{{cite journal | vauthors = Talbot AR, Shiaw MH, Huang JS, Yang SF, Goo TS, Wang SH, Chen CL, Sanford TR | s2cid = 8028945 | title = Acute poisoning with a glyphosate-surfactant herbicide ('Roundup'): a review of 93 cases | journal = Human & Experimental Toxicology | volume = 10 | issue = 1 | pages = 1–8 | date = January 1991 | pmid = 1673618 | doi = 10.1177/096032719101000101 | bibcode = 1991HETox..10....1T }}</ref> Adult consumption of more than 85 ml of concentrated product can lead to corrosive esophageal burns and kidney or liver damage. More severe cases cause "respiratory distress, impaired consciousness, [[pulmonary edema]], [[Pulmonary infiltrate|infiltration]] on chest X-ray, shock, arrhythmias, renal failure requiring haemodialysis, metabolic acidosis, and hyperkalaemia" and death is often preceded by [[bradycardia]] and [[ventricular arrhythmia]]s.<ref name="Bradberry_2004" /> While the surfactants in formulations generally do not increase the toxicity of glyphosate itself, it is likely that they contribute to its acute toxicity.<ref name="Bradberry_2004"/>

====Aquatic fauna====
Glyphosate products for aquatic use generally do not use surfactants, and aquatic formulations do not use POEA due to aquatic organism toxicity.<ref name="Langeland">{{cite web |title=SS-AGR-104 Safe Use of Glyphosate-Containing Products in Aquatic and Upland Natural Areas |url=https://edis.ifas.ufl.edu/pdffiles/AG/AG24800.pdf |publisher=University of Florida |access-date=13 August 2018 |archive-date=March 8, 2021 |archive-url=https://web.archive.org/web/20210308112508/https://edis.ifas.ufl.edu/pdffiles/AG/AG24800.pdf |url-status=dead }}</ref> Due to the presence of POEA, such glyphosate formulations only allowed for terrestrial use are more toxic for amphibians and fish than glyphosate alone.<ref name="Langeland"/><ref name="fs.fed.us"/><ref name=Mann>{{cite journal|vauthors=Mann RM, Hyne RV, Choung CB, Wilson SP|title=Amphibians and agricultural chemicals: Review of the risks in a complex environment|journal=Environmental Pollution|year=2009|volume=157|issue=11|pages=2903–27|doi=10.1016/j.envpol.2009.05.015|pmid=19500891|bibcode=2009EPoll.157.2903M |url=http://hdl.cqu.edu.au/10018/35613}}{{Dead link|date=December 2023 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> The half-life of POEA (21–42 days) is longer than that for glyphosate (7–14 days) in aquatic environments.<ref name="Mesnage">{{cite journal | vauthors = Mesnage R, Defarge N, Spiroux de Vendômois J, Séralini GE | title = Potential toxic effects of glyphosate and its commercial formulations below regulatory limits | journal = Food Chem. Toxicol. | volume = 84 | pages = 133–53 | year = 2015 | pmid = 26282372 | doi = 10.1016/j.fct.2015.08.012 | s2cid = 12725778 | author-link4 = Gilles-Éric Séralini | url = https://kclpure.kcl.ac.uk/portal/en/publications/potential-toxic-effects-of-glyphosate-and-its-commercial-formulations-below-regulatory-limits(e185bac2-4db2-4568-b1d2-f258ed2fe7f3).html }}</ref> Aquatic organism exposure risk to terrestrial formulations with POEA is limited to drift or temporary water pockets where concentrations would be much lower than label rates.<ref name="Langeland"/>

Some researchers have suggested the toxicity effects of pesticides on amphibians may be different from those of other aquatic fauna because of their lifestyle; amphibians may be more susceptible to the toxic effects of pesticides because they often prefer to breed in shallow, [[lentic]], or ephemeral pools. These habitats do not necessarily constitute formal water-bodies and can contain higher concentrations of pesticide compared to larger water-bodies.<ref name="Mann" /><ref name="Govindarajulu">{{cite journal | vauthors= Govindarajulu PP | year = 2008 | title = Literature Review of Impacts of Glyphosate Herbicide on Amphibians: What Risks can the Silvicultural Use of this Herbicide Pose for Amphibians in BC?|publisher=British Columbia, Ecosystems Branch, Ministry of Environment| citeseerx = 10.1.1.314.3577 }}</ref> Studies in a variety of amphibians have shown the toxicity of GBFs containing POEA to amphibian larvae. These effects include interference with gill morphology and mortality from either the loss of osmotic stability or [[asphyxiation]]. At sub-lethal concentrations, exposure to POEA or glyphosate/POEA formulations have been associated with delayed development, accelerated development, reduced size at [[metamorphosis]], developmental malformations of the tail, mouth, eye and head, histological indications of intersex and symptoms of oxidative stress.<ref name="Mann" /> Glyphosate-based formulations can cause [[oxidative stress]] in bullfrog tadpoles.<ref name=iarcmono/>

A 2003 study of various formulations of glyphosate found, "[the] risk assessments based on estimated and measured concentrations of glyphosate that would result from its use for the control of undesirable plants in wetlands and over-water situations showed that the risk to aquatic organisms is negligible or small at application rates less than 4 kg/ha and only slightly greater at application rates of 8 kg/ha."<ref name=Solomon>{{cite journal | vauthors = Solomon KR, Thompson DG | title = Ecological risk assessment for aquatic organisms from over-water uses of glyphosate | journal = Journal of Toxicology and Environmental Health, Part B | volume = 6 | issue = 3 | pages = 289–324 | year = 2003 | pmid = 12746143 | doi = 10.1080/10937400306468 | bibcode = 2003JTEHB...6..289S | s2cid = 42770586 }}</ref>

A 2013 [[meta-analysis]] reviewed the available data related to potential impacts of glyphosate-based herbicides on amphibians. According to the authors, the use of glyphosate-based pesticides cannot be considered the major cause of amphibian decline, the bulk of which occurred prior to the widespread use of glyphosate or in pristine tropical areas with minimal glyphosate exposure. The authors recommended further study of per-species and per-development-stage chronic toxicity, of environmental glyphosate levels, and ongoing analysis of data relevant to determining what if any role glyphosate might be playing in worldwide amphibian decline, and suggest including amphibians in standardized test batteries.<ref name="ReferenceA">{{cite journal | vauthors = Wagner N, Reichenbecher W, Teichmann H, Tappeser B, Lötters S | title = Questions concerning the potential impact of glyphosate-based herbicides on amphibians | journal = Environmental Toxicology and Chemistry | volume = 32 | issue = 8 | pages = 1688–700 | date = Aug 2013 | pmid = 23637092 | doi = 10.1002/etc.2268 | s2cid = 36417341 }}</ref>

====Genetic damage====
Several studies have not found [[mutagen|mutagenic effects]],<ref>ToxNet. [http://toxnet.nlm.nih.gov/cgi-bin/sis/search/a?dbs+hsdb:@term+@DOCNO+3432 Glyposate]. National Library of Medicine.</ref> so glyphosate has not been listed in the [[United States Environmental Protection Agency]] or the [[International Agency for Research on Cancer]] databases.{{Citation needed|date=December 2019|reason=removed citation to predatory publisher content}}  Various other studies suggest glyphosate may be mutagenic.{{Citation needed|date=December 2019|reason=removed citation to predatory publisher content}}  The IARC monograph noted that glyphosate-based formulations can cause DNA strand breaks in various [[Class (biology)|taxa]] of animals ''in vitro''.<ref name=iarcmono/>

===Government and organization positions===
====European Food Safety Authority====
A 2013 systematic review by the [[Federal Institute for Risk Assessment|German Institute for Risk Assessment]] (BfR) examined more than 1000<ref>{{cite web|url=http://www.bfr.bund.de/en/press_information/2014/03/glyphosate__no_more_poisonous_than_previously_assumed__although_a_critical_view_should_be_taken_of_certain_co_formulants-188898.html|title=Glyphosate: no more poisonous than previously assumed, although a critical view should be taken of certain co-formulants – BfR|website=Bfr.bund.de}}</ref> [[epidemiological]] studies, animal studies, and ''[[in vitro]]'' studies. It found that "no classification and labelling for carcinogenicity is warranted" and did not recommend a carcinogen classification of either 1A or 1B.<ref name=BFR2014/>{{rp|34–37, 139}} It provided the review to [[EFSA]] in January 2014 which published it in December 2014.<ref name=BFR2014>Renewal Assessment Report: Glyphosate. Volume 1. Report and Proposed Decision. December 18, 2013. German Institute for Risk Assessment, page 65. Downloaded from http://dar.efsa.europa.eu/dar-web/provision {{Webarchive|url=https://web.archive.org/web/20090130105523/http://dar.efsa.europa.eu/dar-web/provision |date=January 30, 2009 }} (registration required)</ref><ref name="Renewal Assessment Report">{{cite web | url=https://www.scribd.com/doc/238082730/Glyphosate-RAR-01-Volume-1-2013-12-18-San#scribd | title=Glyphosate RAR 01 Volume 1 2013-12-18 San | publisher=Hungry4Pesticides | work=Renewal Assessment Report | date=18 December 2013 | access-date=27 March 2015}}</ref><ref>{{cite web|archive-url=https://web.archive.org/web/20151014145339/http://www.bfr.bund.de/cm/349/frequently-asked-questions-on-the-health-assessment-of-glyphosate.pdf|archive-date=October 14, 2015|publisher=Bundesinstitut für Risikobewertung|date=15 January 2014|url=http://www.bfr.bund.de/cm/349/frequently-asked-questions-on-the-health-assessment-of-glyphosate.pdf|title=Frequently asked questions on the health assessment of glyphosate|url-status=dead|df=mdy-all}}</ref>
In November 2015, EFSA published its conclusion in the Renewal Assessment Report (RAR), stating it was "unlikely to pose a carcinogenic hazard to humans".<ref>{{cite journal | year = 2015 | title = Conclusion on the peer review of the pesticide risk assessment of the active substance glyphosate | journal =  EFSA Journal| volume = 13 | issue = 11| page = 4302 | doi = 10.2903/j.efsa.2015.4302 | doi-access = free | author1 = European Food Safety Authority (EFSA) }}</ref> The [[EU]] was largely informed by this report when it made its decision on the use of glyphosate in November 2017.<ref name="theguardian.com">{{cite news|last1=Nelson|first1=Arthur|title=EU report on weedkiller safety copied text from Monsanto study|url=https://www.theguardian.com/environment/2017/sep/15/eu-report-on-weedkiller-safety-copied-text-from-monsanto-study|newspaper=The Guardian|access-date=September 30, 2017|date=September 14, 2017}}</ref>

EFSA's decision and the BfR report were criticized in an [[open letter]] published by 96 scientists in November 2015 saying that the BfR report failed to adhere to accepted scientific principles of open and transparent procedures.<ref>{{cite news |url=http://www.dw.com/en/independent-scientists-warn-over-monsanto-herbicide/a-18886833 | title=Independent scientists warn over Monsanto herbicide| publisher=[[Deutsche Welle|DW]]| date=December 1, 2015| access-date=December 9, 2015}}</ref><ref name=portier>{{cite letter |recipient=Vytenis Andriukaitis | url = http://db.zs-intern.de/uploads/1448884347-151127_Portier_et_al_EFSA-Glyphosate-Letter.pdf | last = Portier | first = Christopher J. | display-authors=et al | subject=Open letter: Review of the Carcinogenicity of Glyphosate by EFSA and BfR | date = November 27, 2015 | access-date = December 9, 2015 }}</ref> The BfR report included unpublished data, lacked authorship, omitted references, and did not disclose conflict-of-interest information.<ref name=portier/>

In July 2023, EFSA re-evaluated after three years of assessment the putative impact of glyphosate on the health of humans, animals and the environment. As a result, no critical areas of concern were identified that would otherwise prevent glyphosate's registration renewal in the [[EU]].<ref>{{cite journal |last1=Alvarez |first1=Frenando |last2=Arena |first2=Maria |display-authors=1|title=Peer review of the pesticide risk assessment of the active substance glyphosate |journal=EFSA Journal |date=July 2023 |volume=7 |issue=21 |pages=e08164 |doi=10.2903/j.efsa.2023.8164|pmid=37502013 |pmc=10369247 }}</ref><ref>{{Cite web |date=2023-07-06 |title=Glyphosate: no critical areas of concern; data gaps identified {{!}} EFSA |url=https://www.efsa.europa.eu/en/news/glyphosate-no-critical-areas-concern-data-gaps-identified |access-date=2023-07-06 |website=www.efsa.europa.eu |language=en}}</ref><ref name="Open EFSA m798">{{cite web | title=Supporting documents for EFSA-Q-2020-00140 | website=Open EFSA | url=https://open.efsa.europa.eu/study-inventory/EFSA-Q-2020-00140 | access-date=25 August 2023}}</ref>

====International Agency for Research on Cancer====
In March 2015, the [[International Agency for Research on Cancer]] (IARC), an intergovernmental agency forming part of the [[World Health Organization]] of the [[United Nations]], published a summary of their forthcoming monograph on glyphosate, and classified glyphosate as "probably&nbsp;carcinogenic&nbsp;in humans" (category 2A) based on epidemiological studies, animal studies, and ''in vitro'' studies. It noted that there was "limited evidence" of carcinogenicity in humans for [[non-Hodgkin lymphoma]].<ref name=NatureonWHO2015/><ref name=Lancet20March2015/><ref name=IARC20March2015>{{cite web | title = Press release: IARC Monographs Volume 112: evaluation of five organophosphate insecticides and herbicides | date = March 20, 2015 | url = http://www.iarc.fr/en/media-centre/iarcnews/pdf/MonographVolume112.pdf | publisher = International Agency for Research on Cancer, World Health Organization}}</ref><ref name=iarcmono/><ref>{{cite web | first1 = Michael | last1 = Specter | name-list-style = vanc | work = New Yorker | date = 10 April 2015 | url = http://www.newyorker.com/news/daily-comment/roundup-and-risk-assessment | title = Roundup and Risk Assessment | quote = 'Probable' means that there was enough evidence to say it is more than possible, but not enough evidence to say it is a carcinogen," Aaron Blair, a lead researcher on the IARC's study, said. Blair, a scientist emeritus at the National Cancer Institute, has studied the effects of pesticides for years. "It means you ought to be a little concerned about" glyphosate, he said.}}</ref> The IARC classifies substances for their carcinogenic potential, and "a few positive findings can be enough to declare a hazard, even if there are negative studies, as well." Unlike the BfR, it does not conduct a [[risk assessment]], weighing benefits against risk.<ref>{{cite web | url = https://www.nytimes.com/2015/03/28/business/energy-environment/decades-after-monsantos-roundup-gets-an-all-clear-a-cancer-agency-raises-concerns.html | title = Weed Killer, Long Cleared, Is Doubted | first = Andrew | last = Pollack | name-list-style = vanc | date = 27 March 2015 | work = [[New York Times]]}}</ref>

The BfR responded that IARC reviewed only a selection of what they{{who|date=October 2020}} had reviewed earlier, and argued that other studies, including a cohort study called ''Agricultural Health Study'', do not support the classification.<ref>{{cite web | url = http://www.bfr.bund.de/cm/343/loest-glyphosat-krebs-aus.pdf | title = Löst Glyphosat Krebs aus? (announcement 007/2015)|date=23 March 2015|publisher=[[German Institute for Risk Assessment]] | language = de}}</ref> The IARC report did not include unpublished studies, including one completed by the IARC panel leader.<ref>{{Cite news|url=https://www.motherjones.com/environment/2017/06/monsanto-roundup-glyphosate-cancer-who/|title=A scientist didn't disclose important data – and let everyone believe a popular weedkiller causes cancer | last = Butler | first = Kiera | name-list-style = vanc |date=June 15, 2017|work=[[Mother Jones (magazine)|Mother Jones]]|access-date=2017-06-19|language=en-US}}</ref> The agency's international protocol dictates that only published studies be used in classifications of carcinogenicity,<ref>{{cite web | url = http://monographs.iarc.fr/ENG/Preamble/index.php | title = Preamble to the IARC Monographs | year = 2006 | publisher =[[International Agency for Research on Cancer]]}}</ref> since national regulatory agencies including the EPA have allowed agrochemical corporations to conduct their own unpublished research, which may be biased in support of their profit motives.<ref>{{cite web | first1 = Sharon | last1 = Lerner| name-list-style = vanc | url = https://theintercept.com/2015/11/03/epa-used-monsanto-funded-research/| title = EPA used Monsanto's Research to Give Roundup A Pass | date=3 November 2015 | website=[[The Intercept]]|language=en-US}}</ref>

===== Reviews of the EFSA and IARC reports =====
A 2017 review done by personnel from EFSA and BfR argued that the differences between the IARC's and EFSA's conclusions regarding glyphosate and cancer were due to differences in their evaluation of the available evidence. The review concluded that "Two complementary exposure assessments ... suggests that actual exposure levels are below" the reference values identified by the EFSA "and do not represent a public concern."<ref name=Tarazona/>

In contrast, a 2016 analysis by Christopher Portier, a scientist advising the IARC in the assessment of glyphosate and advocate for its classification as possibly carcinogenic, concluded that in the EFSA's ''Renewal Assessment Report'', "almost no weight is given to studies from the published literature and there is an over-reliance on non-publicly available industry-provided studies using a limited set of assays that define the minimum data necessary for the marketing of a pesticide", arguing that the IARC's evaluation of ''probably carcinogenic to humans'' "accurately reflects the results of published scientific literature on glyphosate".<ref>{{cite journal | vauthors = Portier CJ, Armstrong BK, Baguley BC, Baur X, Belyaev I, Bellé R, Belpoggi F, Biggeri A, Bosland MC, Bruzzi P, Budnik LT, Bugge MD, Burns K, Calaf GM, Carpenter DO, Carpenter HM, López-Carrillo L, Clapp R, Cocco P, Consonni D, Comba P, Craft E, Dalvie MA, Davis D, Demers PA, De Roos AJ, DeWitt J, Forastiere F, Freedman JH, Fritschi L, Gaus C, Gohlke JM, Goldberg M, Greiser E, Hansen J, Hardell L, Hauptmann M, Huang W, Huff J, James MO, Jameson CW, Kortenkamp A, Kopp-Schneider A, Kromhout H, Larramendy ML, Landrigan PJ, Lash LH, Leszczynski D, Lynch CF, Magnani C, Mandrioli D, Martin FL, Merler E, Michelozzi P, Miligi L, Miller AB, Mirabelli D, Mirer FE, Naidoo S, Perry MJ, Petronio MG, Pirastu R, Portier RJ, Ramos KS, Robertson LW, Rodriguez T, Röösli M, Ross MK, Roy D, Rusyn I, Saldiva P, Sass J, Savolainen K, Scheepers PT, Sergi C, Silbergeld EK, Smith MT, Stewart BW, Sutton P, Tateo F, Terracini B, Thielmann HW, Thomas DB, Vainio H, Vena JE, Vineis P, Weiderpass E, Weisenburger DD, Woodruff TJ, Yorifuji T, Yu IJ, Zambon P, Zeeb H, Zhou SF | display-authors = 1 | title = Differences in the carcinogenic evaluation of glyphosate between the International Agency for Research on Cancer (IARC) and the European Food Safety Authority (EFSA) | journal = Journal of Epidemiology and Community Health | volume = 70 | issue = 8 | pages = 741–45 | date = August 2016 | pmid = 26941213 | pmc = 4975799 | doi = 10.1136/jech-2015-207005 }}</ref>

In October 2017, an article in ''The Times'' revealed that Portier had received consulting contracts with two law firm associations representing alleged glyphosate cancer victims that included a payment of US$160,000 to Portier.<ref>{{Cite news|url=https://www.faz.net/1.5248763|title=Herbizid: Der dramatische Kampf um die Deutungshoheit von Glyphosat|last=Grossarth|first=Jan|work=FAZ.NET|access-date=2019-01-06|language=de|issn=0174-4909}}</ref><ref>{{Cite news|url=https://www.thetimes.co.uk/article/weedkiller-scientist-was-paid-120-000-by-cancer-lawyers-v0qggbrk6|title=Weedkiller scientist was paid £120,000 by cancer lawyers|last=Webster|first=Ben |date=2017-10-18|work=The Times|access-date=2019-01-06|language=en|issn=0140-0460}}</ref> The IARC final report was also found to have changed compared to an interim report, through the removal of text saying certain studies had found glyphosate was not carcinogenic in that study's context, and through strengthening a conclusion of "limited evidence of animal carcinogenicity," to "sufficient evidence of animal carcinogenicity".<ref>{{Cite news|url=https://www.reuters.com/investigates/special-report/who-iarc-glyphosate/|title=Glyphosate: WHO cancer agency edited out|last=Kelland|first=Kate|website=Reuters|language=en|access-date=2019-01-06}}</ref>

====US Environmental Protection Agency====
In a 1993 review, the [[EPA]], considered glyphosate to be [[carcinogenic|noncarcinogenic]] and relatively low in [[dermal]] and oral acute toxicity.<ref name="epa_reds">{{cite web | url = https://www3.epa.gov/pesticides/chem_search/reg_actions/reregistration/fs_PC-417300_1-Sep-93.pdf | title = Registration Decision Fact Sheet for Glyphosate (EPA-738-F-93-011) | year = 1993 | work = R.E.D. FACTS | publisher = United States Environmental Protection Agency }}</ref>  The EPA considered a "worst case" dietary risk model of an individual eating a lifetime of food derived entirely from glyphosate-sprayed fields with residues at their maximum levels. This model indicated that no adverse health effects would be expected under such conditions.<ref name="epa_reds" /> In 2015, the EPA initiated a review of glyphosate's toxicity and in 2016 reported that glyphosate is likely not carcinogenic.<ref name=NatureonWHO2015>{{cite journal | first1 = Daniel | last1 = Cressey | name-list-style = vanc | url = http://www.nature.com/news/widely-used-herbicide-linked-to-cancer-1.17181 | title = Widely used herbicide linked to cancer | journal = Nature | date = March 25, 2015 | doi = 10.1038/nature.2015.17181 | s2cid = 131732731 | doi-access = free }}</ref><ref>{{cite news |last=Charles|first=Dan | name-list-style = vanc |date=17 September 2016|title=EPA Weighs In On Glyphosate, Says It Doesn't Cause Cancer|url=https://www.npr.org/sections/thesalt/2016/09/17/494301343/epa-weighs-in-on-glyphosate-says-it-doesnt-cause-cancer|newspaper=[[NPR]]|access-date=19 September 2016}}</ref> In August 2019, the [[United States Environmental Protection Agency|EPA]] announced that it no longer allowed labels claiming glyphosate is a carcinogen, as those claims would "not meet the labeling requirements of the [[Federal Insecticide, Fungicide, and Rodenticide Act]]" and misinform the public.<ref name="auto">{{cite web |title=EPA Takes Action to Provide Accurate Risk Information to Consumers, Stop False Labeling on Products |url=https://www.epa.gov/newsreleases/epa-takes-action-provide-accurate-risk-information-consumers-stop-false-labeling |publisher=US EPA |access-date=28 October 2019 |language=en |date=8 August 2019}}</ref>

In 2017, evidence collected in a lawsuit brought against Monsanto by cancer patients revealed company emails which appeared to show a friendly relationship with a senior EPA official.<ref>{{cite web |last1=Charles |first1=Dan |title=Emails Reveal Monsanto's Tactics To Defend Glyphosate Against Cancer Fears |url=https://www.npr.org/sections/thesalt/2017/03/15/520250505/emails-reveal-monsantos-tactics-to-defend-glyphosate-against-cancer-fears |website=NPR |date=March 15, 2017 |access-date=May 14, 2019}}</ref>
===== Monsanto response and campaign =====
Monsanto called the IARC report biased and said it wanted the report to be retracted.<ref>{{cite web|url=https://www.reuters.com/article/us-monsanto-herbicide-idUSKBN0MK2GF20150324#TWrEqcrkJiYtdXgJ.97|title=Monsanto seeks retraction for report linking herbicide to cancer|last1=Gillam|first1=Carey|date=24 March 2015|work=Reuters|name-list-style=vanc}}</ref> In 2017, internal documents from Monsanto were made public by lawyers pursuing litigation against the company,<ref>{{Cite web|url=http://baumhedlundlaw.com/pdf/monsanto-documents/72-Document-Details-Monsantos-Goals-After-IARC-Report.pdf|title=Glyphosate: IARC (Monsanto shared document)|date=February 23, 2015|website=Baum Hedlund Law|access-date=2018-06-03}}</ref> who used the term "Monsanto papers" to describe the documents.<ref>{{cite web|url=https://www.baumhedlundlaw.com/toxic-tort-law/monsanto-roundup-lawsuit/monsanto-secret-documents/|title=Monsanto Papers: Secret Documents|publisher=Baum, Hedlund, Aristei & Goldman, PC|access-date=2019-10-31}}</ref> This term was later used also by [[Leemon McHenry]]<ref>{{Cite journal|last=McHenry|first=Leemon B.|date=2018|title=The Monsanto Papers: Poisoning the scientific well|journal=International Journal of Risk & Safety in Medicine|url=https://content.iospress.com/articles/international-journal-of-risk-and-safety-in-medicine/jrs180028|volume=29|issue=3–4|pages=193–205|doi=10.3233/JRS-180028|issn=1878-6847|pmid=29843257|s2cid=44179710 }}</ref> and others.<ref>{{Cite web|url=https://www.industrydocuments.ucsf.edu/chemical/collections/roundup-litigation-documents/|title=Chemical Industry Documents Library|language=en-US|access-date=2019-11-02}}</ref> The documents indicated Monsanto had planned a public relations effort to discredit the IARC report, and had engaged [[Henry I. Miller|Henry Miller]] to write a 2015 opinion piece in ''[[Forbes Magazine]]'' challenging the report. Miller did not reveal the connection to Forbes, and according to the ''[[New York Times]]'', when Monsanto asked him if he was interested in writing such an article, he replied "I would be if I could start from a high-quality draft" provided by the company.<ref>{{Cite news|url=https://www.nytimes.com/2017/08/01/business/monsantos-sway-over-research-is-seen-in-disclosed-emails.html|title=Monsanto Emails Raise Issue of Influencing Research on Roundup Weed Killer|last=Hakim|first=Danny|date=2017-08-01|work=The New York Times|access-date=2019-10-26|language=en-US|issn=0362-4331}}</ref> Once this became public, Forbes removed his blog from their site.

Two journalists from ''[[Le Monde]]'' won the 2018 [[European Press Prize]] for a series of articles on the documents, also titled ''Monsanto Papers''. Their reporting described, among other things, Monsanto's lawyers' letters demanding that IARC scientists turn over documents relating to ''Monograph 112'', which contained the IARC finding that glyphosate was a "probable carcinogen"; several of the scientists condemned these letters as intimidating.<ref name="EPP">{{cite web|website=European Press Prize|url=https://www.europeanpressprize.com/article/monsanto-papers/|author1=Stéphane Foucart|author2=Stéphane Horel|title= The Investigative Reporting Award 2018 Winner: Monsanto Papers|access-date=31 March 2019|quote=[T]he non-American scientists who had been members of the IARC panel on glyphosate all received the same letter. Sent by Monsanto’s law firm, Hollingsworth, the letter told them to hand over all the files related to their work on ''Monograph 112''.}}</ref>

====California Office of Environmental Health Hazard Assessment====
In March 2015, the [[California Office of Environmental Health Hazard Assessment]] (OEHHA) announced plans to have glyphosate listed as a known carcinogen based on the IARC assessment. In 2016, Monsanto started a case against OEHHA and its acting director, Lauren Zeise,<ref>{{Cite news|title = Monsanto Sues California Over Herbicide Classification|url = https://www.nytimes.com/2016/01/22/business/monsanto-sues-california-over-herbicide-classification.html|newspaper = The New York Times|date=2016-01-21|access-date=2016-01-25|issn = 0362-4331|agency = Reuters}}</ref> but lost the suit in March 2017.<ref>{{Cite news|title=Monsanto loses cancer label lawsuit, accused of ghostwriting study|url = http://www.bizjournals.com/stlouis/news/2017/03/14/monsanto-loses-cancer-label-lawsuit-accused-of.html|newspaper = St. Louis Business Journal|date=2017-03-14|access-date=2017-06-28}}</ref>

Glyphosate was listed as "known to the State of California to cause cancer" in 2017, requiring warning labels under [[Proposition 65]].<ref>{{Cite web|url=https://oehha.ca.gov/proposition-65/crnr/glyphosate-listed-effective-july-7-2017-known-state-california-cause-cancer|title=Glyphosate Listed Effective July 7, 2017, as Known to the State of California to Cause Cancer |website=oehha.ca.gov|language=en|access-date=2017-07-07}}</ref> In February 2018, as part of an ongoing case, an injunction was issued prohibiting California from enforcing carcinogenicity labeling requirements for glyphosate until the case was resolved. The injunction stated that arguments by a [[US District Court Judge]] for the [[Eastern District of California]] "[do] not change the fact that the overwhelming majority of agencies that that have examined glyphosate have determined it is not a cancer risk."<ref>{{cite news |title=Federal judge rules against California's attorney general over glyphosate |url=http://www.agweek.com/business/agriculture/4460533-federal-judge-rules-against-californias-attorney-general-over |access-date=14 August 2018 |publisher=AgWeek|date=14 June 2018|language=en}}</ref> In August 2019, the [[United States Environmental Protection Agency|EPA]] also said it no longer allowed labels claiming glyphosate is a carcinogen, as those claims would "not meet the labeling requirements of the [[Federal Insecticide, Fungicide, and Rodenticide Act]]" and misinform the public.<ref name="auto"/>

====European Chemicals Agency====
On March 15, 2017 the [[European Chemicals Agency]] (ECHA) announced recommendations proceeding from a risk assessment of glyphosate performed by ECHA's Committee for Risk Assessment (RAC).  Their recommendations maintained the current classification of glyphosate as a substance causing serious eye damage and as a substance toxic to aquatic life.  However, the RAC did not find evidence implicating glyphosate to be a carcinogen, a mutagen, toxic to reproduction, nor toxic to specific organs.<ref>{{cite web|url=https://echa.europa.eu/-/glyphosate-not-classified-as-a-carcinogen-by-echa|title=Glyphosate not classified as a carcinogen by ECHA |website=echa.europa.eu}}</ref> In 2022, the agency reiterated these findings in a later review and stated on cancer risk that, "Based on a wide-ranging review of scientific evidence, the committee again concludes that classifying glyphosate as a carcinogen is not justified."<ref>{{cite web |title=Glyphosate: no change proposed to hazard classification|url=https://echa.europa.eu/sk/-/glyphosate-no-change-proposed-to-hazard-classification |website=echa.europa.eu |publisher=European Chemicals Agency |access-date=26 May 2023 |language=sk-SK}}</ref>

==Effects of use==
===Emergence of resistant weeds===
In the 1990s, no [[glyphosate resistance|glyphosate-resistant]] weeds were known to exist.<ref name="NYT_2010" /> In 2005 a slow upward trend began, resistant weeds appearing rarely around the world.<ref name="Trends" /> Another [[inflection point]] occurred in 2011 and resistance accelerated globally.<ref name="Trends">
:{{cite journal|issue=2|year=2017|publisher=[[John Wiley & Sons, Inc.]]|pages=48–60|last=Carvalho|volume=6|first=Fernando|journal=[[Food and Energy Security]]|issn=2048-3694|s2cid=89994510|doi=10.1002/fes3.108|title=Pesticides, environment, and food safety|doi-access=free}}
:
:{{cite journal|issue=1|year=2016|publisher=[[Springer Science and Business Media LLC]]|last1=Peterson|volume=15|first1=John|last2=Antoniou|first2=Michael|last3=Blumberg|first3=Bruce|last4=Carroll|first4=Lynn|last5=Colborn|first5=Theo|last6=Everett|first6=Lorne|last7=Hansen|first7=Michael|last8=Landrigan|first8=Philip|last9=Lanphear|first9=Bruce|last10=Mesnage|first10=Robin|last11=Vandenberg|first11=Laura|last12=vom Saal|first12=Frederick|last13=Welshons|first13=Wade|last14=Benbrook|first14=Charles|journal=[[Environmental Health (journal)|Environmental Health]]|issn=1476-069X|s2cid=10631819|doi=10.1186/s12940-016-0117-0|title=Concerns over use of glyphosate-based herbicides and risks associated with exposures: a consensus statement|page=19 |pmid=26883814 |pmc=4756530 |bibcode=2016EnvHe..15...19M |doi-access=free }}
:
:These reviews cite this research.
:
:{{cite journal|issue=1|year=2016|publisher=[[Springer Science and Business Media LLC]]|volume=28|last=Benbrook|first=Charles|journal=[[Environmental Sciences Europe]]|issn=2190-4707|s2cid=1660085|doi=10.1186/s12302-016-0070-0|title=Trends in glyphosate herbicide use in the United States and globally|page=3 |pmid=27752438 |pmc=5044953 |doi-access=free }}
</ref> By 2014, glyphosate-resistant weeds dominated herbicide-resistance research. At that time, 23 glyphosate-resistant species were found in 18 countries.<ref name="springer_2016_heap_2014" /> "Resistance evolves after a weed population has been subjected to intense selection pressure in the form of repeated use of a single herbicide."<ref name="NYT_2010">{{cite news| url=https://www.nytimes.com/2010/05/17/opinion/17mon3.html?ref=opinion | work=The New York Times | title=Resisting Roundup | date=May 16, 2010 |access-date=March 24, 2016}}</ref><ref name="canada"/>

According to Ian Heap, a weed specialist, who completed his PhD on resistance to multiple herbicides in annual ryegrass (''[[Lolium rigidum]]'') in 1988<ref name="Heap_PhD_1988">{{cite book | title=Resistance to herbicides in annual ryegrass (Lolium Rigidum) | publisher=Department of Agronomy, [[University of Adelaide]] | date=1988 | author=Heap, Ian Michael | location=Adelaide}}</ref> – the first case of an herbicide-resistant weed in Australia<ref name="agannex_2015">{{cite web | url=http://www.agannex.com/weeds/history-of-herbicide-resistance | title=History of herbicide resistance Herbicide resistance: Then, now, and the years to come | date=June 2015 | access-date=24 March 2016 | author=King, Carolyn | archive-date=July 3, 2015 | archive-url=https://web.archive.org/web/20150703010649/http://www.agannex.com/weeds/history-of-herbicide-resistance | url-status=dead }}</ref> – by 2014 ''Lolium rigidum'' was the "world’s worst herbicide-resistant weed" with instances in "12 countries, 11 sites of action, 9 cropping regimens" and affecting "over 2 million hectares."<ref name="springer_2016_heap_2014">{{cite book |doi=10.1007/978-94-007-7796-5_12 |chapter=Herbicide Resistant Weeds |title=Integrated Pest Management |pages=281–301 |year=2014 |last1=Heap |first1=Ian |publisher=Springer |location=Dordrecht |isbn=978-94-007-7795-8 }}</ref> Annual ryegrass has been known to be resistant to herbicides since 1982. The first documented case of glyphosate-resistant ''L. rigidum'' was reported in Australia in 1996 near [[Orange, New South Wales]].<ref name="weeds_iastate_1998">{{citation |url=http://www.weeds.iastate.edu/mgmt/2003/glyresistance.shtml |series=Weed Science Online |title=Are Roundup Ready Weeds in Your Future II |first=Bob |last=Hartzler |name-list-style=vanc |date=January 29, 2003 |access-date=March 24, 2016 |work=Iowa State University (ISU) |archive-date=March 5, 2016 |archive-url=https://web.archive.org/web/20160305021727/http://www.weeds.iastate.edu/mgmt/2003/glyresistance.shtml |url-status=dead }}</ref><ref>{{cite journal | vauthors = Powles SB, Lorraine-Colwill DF, Dellow JJ, Preston C | year = 1998 | title = Evolved Resistance to Glyphosate in Rigid Ryegrass (Lolium rigidum) in Australia | journal = Weed Science | volume = 46 | issue = 5 | pages = 604–07 | jstor = 4045968 | doi = 10.1017/S0043174500091165 | s2cid = 83591923 }}</ref><ref name=ResistanceBook2010>Glyphosate Resistance in Crops and Weeds: History, Development, and Management. Editor, Vijay K. Nandula. John Wiley & Sons, 2010 {{ISBN|978-1118043547}}</ref> In 2006, farmers associations were reporting 107 biotypes of weeds within 63 weed species with herbicide resistance.<ref name="SEFarmPressResistance">{{Cite web|url=http://southeastfarmpress.com/glyphosate-resistant-weeds-reality-cotton-growers/ |title=Glyphosate resistance is a reality that should scare some cotton growers into changing the way they do business |publisher=Southeastfarmpress.com |access-date=2010-08-22|date=February 10, 2006 }}</ref> In 2009, Canada identified its first resistant weed, [[giant ragweed]], and at that time 15 weed species had been confirmed as resistant to glyphosate.<ref name="canada">{{Cite web|author=Lori |url=http://www.uoguelph.ca/news/2009/05/u_of_g_research_19.html |title=U of G Researchers Find Suspected Glyphosate-Resistant Weed |publisher=Uoguelph.ca |date=2009-05-07 |access-date=2010-08-22}}</ref><ref name="WeedScience-resistance">{{cite web |url=http://weedscience.org/Summary/MOA.aspx?MOAID=12 | title = List of Herbicide Resistant Weeds by Herbicide Mode of Action - Weeds Resistant to EPSP synthase inhibitors (G/9) | publisher=[[Herbicide Resistance Action Committee]]|website=The International Survey of Herbicide Resistant Weeds | year=2020 | access-date=22 November 2020 | vauthors = Heap I}}</ref> As of 2010, in the United States {{convert|7|to|10|e6acre|e6ha|abbr=off}} of soil were afflicted by herbicide-resistant weeds, or about 5% of the 170 million acres planted with corn, soybeans, and cotton, the crops most affected, in 22 states.<ref name="nytimes">{{Cite news|url=https://www.nytimes.com/2010/05/04/business/energy-environment/04weed.html|title=U.S. Farmers Cope With Roundup-Resistant Weeds | vauthors = Neuman W, Pollack A | date = 4 May 2010 | work = [[The New York Times]] | pages = B1 | access-date = 4 May 2010 | location = New York }}</ref> In 2012, Charles Benbrook reported that the [[Weed Science Society of America]] listed 22 herbicide-resistant species in the U.S., with over {{convert|5.7|e6ha|e6acre|abbr=on}} infested by GR weeds and that [[Dow AgroSciences]] had carried out a survey and reported a figure of around {{convert|40|e6ha|e6acre|sigfig=1|abbr=on}}.<ref name=Benbrook2012>{{cite journal |doi=10.1186/2190-4715-24-24 |title=Impacts of genetically engineered crops on pesticide use in the U.S. – the first sixteen years |journal=Environmental Sciences Europe |volume=24 |pages=24 |year=2012 |last1=Benbrook |first1=Charles M |issue=1 |doi-access=free }}</ref> The International Survey of Herbicide Resistant Weeds database lists species that are resistant to glyphosate.<ref name="WeedScience-resistance" />

In response to resistant weeds, farmers are hand-weeding, using tractors to turn over soil between crops, and using other herbicides in addition to glyphosate.

Monsanto scientists have found that some resistant weeds have as many as 160 extra copies of a gene called ''[[EPSP synthase|EPSPS]],'' the enzyme glyphosate disrupts.<ref>{{cite web | title = With BioDirect, Monsanto Hopes RNA Sprays Can Someday Deliver Drought Tolerance and Other Traits to Plants on Demand | work = [[MIT Technology Review]] | url = http://www.technologyreview.com/featuredstory/540136/the-next-great-gmo-debate | access-date = 2015-08-31}}</ref>

====Palmer amaranth====
[[File:Amaranthus palmeri.jpg|thumb|upright|[[Palmer amaranth]] (''Amaranthus palmeri'')]]
In 2004, a glyphosate-resistant variation of [[Amaranthus palmeri|Palmer amaranth]] was found in the U.S. state of Georgia.<ref name="Culpepper">{{cite journal |doi=10.1614/WS-06-001R.1 |title= Glyphosate-resistant Palmer amaranth (''Amaranthus palmeri'') confirmed in Georgia |year=2006 |vauthors=Culpepper AS, Grey TL, Vencill WK, Kichler JM, Webster TM, Brown SM, York AC, Davis JW, Hanna WW |s2cid= 56236569 | journal =[[Weed Science (journal)|Weed Science]] | volume = 54 | issue = 4 | pages = 620–26 | jstor = 4539441 }}</ref> In 2005, resistance was also found in North Carolina.<ref name="Hampton">{{cite web | url = http://www.cals.ncsu.edu/agcomm/magazine/winter09/cotton.html | title = Cotton versus the monster weed| last= Hampton |first = Natalie |date = Winter 2009|website = College of Agriculture and Life Science|publisher = North Carolina State University}}</ref> The species can quickly become resistant to multiple herbicides and has developed multiple mechanisms for glyphosate resistance due to [[selection pressure]].<ref>{{cite journal |last1=Ward |first1=Sarah M. |last2=Webster |first2=Theodore M. |last3=Steckel |first3=Larry E. |title=Palmer Amaranth (''Amaranthus palmeri''): A Review |journal=[[Weed Technology]]|date=20 January 2017 |volume=27 |issue=1 |pages=12–27 |doi=10.1614/WT-D-12-00113.1|s2cid=84142912 |doi-access=free }}</ref><ref name="Hampton"/> The glyphosate-resistant weed variant is now widespread in the southeastern United States.<ref name="Culpepper"/><ref name="FS03Mar09">{{cite news | url = http://magissues.farmprogress.com/TFS/FS03Mar09/tfs024.pdf | title = Resistance a growing problem | vauthors = Smith JT | date = March 2009 | work = The Farmer Stockman | access-date = 2009-07-19 | archive-date = July 10, 2011 | archive-url = https://web.archive.org/web/20110710224650/http://magissues.farmprogress.com/TFS/FS03Mar09/tfs024.pdf | url-status = dead }}</ref> Cases have also been reported in Texas<ref name="FS03Mar09"/> and Virginia.<ref>{{cite web | url = http://agfax.com/news/2009/peanutfax/0716pf.htm | title = Peanuts: variable insects, variable weather, Roundup resistant Palmer in new state | vauthors = Taylor O | date = 2009-07-16 | work =[[PeanutFax]]| publisher =[[AgFax Media]]| access-date = 2009-07-19 | archive-date = July 7, 2011 | archive-url = https://web.archive.org/web/20110707093545/http://agfax.com/news/2009/peanutfax/0716pf.htm | url-status = dead }}</ref>

====''Conyza'' species====
[[File:Canadese fijnstraal plant Conyza canadensis.jpg|thumb|upright|[[Conyza canadensis|Horseweed]]]]
''[[Conyza bonariensis]]'' (also known as hairy fleabane and buva) and ''[[Conyza canadensis|C. canadensis]]'' (known as horseweed or marestail) are other weed species that have lately developed glyphosate resistance.<ref>{{cite journal |doi=10.1590/S0100-83582007000300017 |title=Buva (''Conyza bonariensis'') resistente ao glyphosate na região sul do Brasil |trans-title=''Conyza bonariensis'' biotypes resistant to the glyphosate in southern Brazil |language=pt |year=2007 |vauthors=Vargas L, Bianchi MA, Rizzardi MA, Agostinetto D, Dal Magro T |journal=Planta Daninha |volume=25 |issue=3 |pages=573–78|doi-access=free }}</ref><ref>{{cite journal |doi=10.1614/WS-05-010R |title=Assessment of two nondestructive assays for detecting glyphosate resistance in horseweed (''Conyza canadensis'') |year=2005 |vauthors=Koger CH, Shaner DL, Henry WB, Nadler-Hassar T, Thomas WE, Wilcut JW |s2cid=198128423 | journal =[[Weed Science (journal)|Weed Science]]| volume = 53 | issue = 4 | pages = 438–45 | jstor = 4047050}}</ref><ref name="pmid20063320">{{cite journal | vauthors = Ge X, d'Avignon DA, Ackerman JJ, Sammons RD | title = Rapid vacuolar sequestration: the horseweed glyphosate resistance mechanism | journal = [[Pest Management Science]] | volume = 66 | issue = 4 | pages = 345–48 | date = Apr 2010 | pmid = 20063320 | pmc = 3080097 | doi = 10.1002/ps.1911 }}</ref> A 2008 study on the current situation of glyphosate resistance in South America concluded "resistance evolution followed intense glyphosate use" and the use of glyphosate-resistant soybean crops is a factor encouraging increases in glyphosate use.<ref name="pmid18161884">{{cite journal | vauthors = Vila-Aiub MM, Vidal RA, Balbi MC, Gundel PE, Trucco F, Ghersa CM | title = Glyphosate-resistant weeds of South American cropping systems: an overview | journal =[[Pest Management Science]]| volume = 64 | issue = 4 | pages = 366–71 | date = Apr 2008 | pmid = 18161884 | doi = 10.1002/ps.1488 }}</ref> In the 2015 growing season, glyphosate-resistant marestail proved to be especially problematic to control in Nebraska production fields.<ref name=cw-marestail>{{cite news|last1=Jhala|first1=Amit|title=Post-Emergence Herbicide Options for Glyphosate-Resistant Marestail in Corn and Soybean|url=http://cropwatch.unl.edu/controlling-glyphosate-resistant-marestail|access-date=17 August 2015|agency=[[Nebraska Extension]]|publisher=[[CropWatch]]|date=4 June 2015 | name-list-style = vanc }}</ref>

====Ryegrass====
[[File:Lolium perenne Engels raaigras doorgeschoten plant.jpg|thumb|upright|[[Ryegrass]]]]
Glyphosate-resistant [[ryegrass]] (''Lolium'') has occurred in most of the Australian agricultural areas and other areas of the world. All cases of evolution of resistance to glyphosate in Australia were characterized by intensive use of the herbicide while no other effective weed control practices were used. Studies indicate resistant ryegrass does not compete well against nonresistant plants and their numbers decrease when not grown under conditions of glyphosate application.<ref>{{cite journal | title = A Decade of Glyphosate-Resistant Lolium around the World: Mechanisms, Genes, Fitness, and Agronomic Management |year=2009 |vauthors=Preston C, Wakelin AM, Dolman FC, Bostamam Y, Boutsalis P |s2cid=85725624 | journal =[[Weed Science (journal)|Weed Science]]| volume = 57 | issue = 4 | pages = 435–41 | doi = 10.1614/WS-08-181.1 }}</ref>

====Johnson grass====
Glyphosate-resistant [[Johnson grass]] (''Sorghum halepense'') has been found in Argentina as well as Arkansas, Louisiana, and Mississippi.<ref>{{cite journal |last1=Peerzada |first1=Arslan Masood |last2=Ali |first2=Hafiz Haider |last3=Hanif |first3=Zarka |last4=Bajwa |first4=Ali Ahsan |last5=Kebaso |first5=Lynda |last6=Frimpong |first6=David |last7=Iqbal |first7=Nadeem |last8=Namubiru |first8=Halima |last9=Hashim |first9=Saima |last10=Rasool |first10=Ghulam |last11=Manalil |first11=Sudheesh |last12=van der Meulen |first12=Annemieke |last13=Chauhan |first13=Bhagirath Singh |display-authors=1|title=Eco-biology, impact, and management of ''Sorghum halepense'' (L.) Pers. |journal=[[Biological Invasions]]|date=16 March 2017 |volume=25 |issue=4 |pages=955–973 |doi=10.1007/s10530-017-1410-8|s2cid=17096998 |url=https://espace.library.uq.edu.au/view/UQ:547820/UQ547820_OA.pdf }}</ref>

===Monarch butterfly populations===
Use of glyphosate and other herbicides like [[2,4-D]] to clear [[Asclepias|milkweed]] along roads and fields may have contributed to a decline in [[monarch butterfly]] populations in the Midwestern United States.<ref>{{cite web |url=http://weedcontrolfreaks.com/2014/02/are-herbicides-responsible-for-the-decline-in-monarch-butterflies/ |title=Are herbicides responsible for the decline in Monarch butterflies? |last1=Kniss |first1=Andrew |name-list-style=vanc |date=2014-02-10 |website=Control Freaks |access-date=2016-06-16 |quote=The evidence seems clear that the number of milkweed plants through this region has indeed declined. The cause for the milkweed decline, though, is a little less certain. |archive-date=August 29, 2016 |archive-url=https://web.archive.org/web/20160829045127/http://weedcontrolfreaks.com/2014/02/are-herbicides-responsible-for-the-decline-in-monarch-butterflies/ |url-status=dead }}</ref> Along with deforestation and adverse weather conditions,<ref>{{cite news |url=https://www.washingtonpost.com/news/wonk/wp/2014/01/29/the-monarch-butterfly-population-just-hit-a-record-low-heres-why/ |title=Monarch butterflies keep disappearing. Here's why. |last=Plumer |first=Brad  | name-list-style = vanc |date=January 29, 2014  |newspaper=The Washington Post |access-date=2016-06-16}}</ref> the decrease in milkweed contributed to an 81% decline in monarchs.<ref>{{cite journal |doi=10.1111/j.1752-4598.2012.00196.x |title=Milkweed loss in agricultural fields because of herbicide use: Effect on the monarch butterfly population |journal=[[Insect Conservation and Diversity]]|volume=6 |issue=2 |pages=135–44 |year=2013 |last1=Pleasants |first1=John M |last2=Oberhauser |first2=Karen S |s2cid=14595378 |url=http://osf.io/wmj6e | name-list-style = vanc }}</ref><ref>{{cite journal |doi=10.1016/s0261-2194(00)00024-7 |title=Occurrence of common milkweed (Asclepias syriaca) in cropland and adjacent areas |journal=[[Crop Protection (journal)|Crop Protection]]|volume=19 |issue=5 |pages=363–66 |year=2000 |last1=Hartzler |first1=Robert G |last2=Buhler |first2=Douglas D |bibcode=2000CrPro..19..363H | name-list-style = vanc |url=https://lib.dr.iastate.edu/agron_pubs/32 }}</ref> The [[Natural Resources Defense Council]] (NRDC) filed a suit against the [[EPA]] in 2015, in which it argued that the agency ignored warnings about the potentially dangerous impacts of glyphosate usage on monarchs.<ref>{{cite web | title = NRDC Sues EPA Over Demise of Monarch Butterfly Population | url = http://www.nbcnews.com/science/environment/nrdc-sues-epa-over-demise-monarch-butterfly-population-n314371 | year = 2015 | work = NBC }}</ref>

==Legal status==
Glyphosate was first approved for use in the 1970s, and as of 2010 was labelled for use in 130 countries.<ref name=Dill/>{{rp|2}}

In 2017 Vandenberg ''et al.'' cited a 100-fold increase in the use of glyphosate-based herbicides from 1974 to 2014, the possibility that herbicide mixtures likely have effects that are not predicted by studying glyphosate alone, and reliance of current safety assessments on studies done over 30 years ago. They recommended that current safety standards be updated, writing that the current standards "may fail to protect public health or the environment."<ref>{{cite journal|url= |title=Is it time to reassess current safety standards for glyphosate-based herbicides?|vauthors=Vandenberg LN, Blumberg B, Antoniou MN, Benbrook CM, Carroll L, Colborn T, Everett LG, Hansen M, Landrigan PJ, Lanphear BP, Mesnage R, vom Saal FS, Welshons WV, Myers JP|date=June 2017|journal=[[J Epidemiol Community Health]]|volume=71|issue=6|pages=613–18|doi=10.1136/jech-2016-208463|pmid=28320775|pmc=5484035}}</ref>

===Europe===
In April 2014, the legislature of the [[Netherlands]] passed legislation prohibiting sale of glyphosate to individuals for use at home; commercial sales were not affected.<ref>Staff, Sustainable Pulse. Apr 4 2014 [http://sustainablepulse.com/2014/04/04/dutch-parliament-bans-glyphosate-herbicides-non-commercial-use Dutch Parliament Bans Glyphosate Herbicides for Non-Commercial Use]</ref>

In June 2015, the [[Ministry of the Ecological Transition (France)|French Ecology Minister]] asked nurseries and garden centers to halt over-the-counter sales of glyphosate in the form of Monsanto's Roundup. This was a nonbinding request and all sales of glyphosate remain legal in France until 2022, when it was planned to ban the substance for home gardening.<ref name="url_Reuters_France">{{cite news | url = https://www.reuters.com/article/france-monsanto-idUSL5N0Z00H120150614?type=companyNews | title = French minister asks shops to stop selling Monsanto Roundup weedkiller | newspaper = [[Reuters]] | date = June 14, 2015 }}</ref> However, more recently the French parliament decided to not to impose a definitive date for such a ban.<ref>
French parliament does not vote for a date to terminate glyphosate:
[https://www.lemonde.fr/planete/article/2018/05/29/l-assemblee-nationale-ne-vote-pas-de-date-pour-la-fin-du-glyphosate_5306106_3244.html Rejet à l’Assemblée de l’inscription dans la loi de la date de sortie du glyphosate]</ref> In January 2019, "the sale, distribution, and use of Roundup 360 [wa]s banned" in France. Exemptions for many farmers were later implemented, and a curb of its use by 80% for 2021 is projected.<ref>{{Cite web|url=https://www.france24.com/en/20190116-weedkiller-roundup-banned-france-after-court-ruling|title=Weedkiller Roundup banned in France after court ruling|date=2019-01-16|website=France 24|language=en|access-date=2019-01-16}}</ref><ref name=FrenchBan>{{cite news|newspaper=Reuters|title=French court cancels Monsanto weedkiller permit on safety grounds|date=15 January 2019|access-date=16 January 2019|url=https://www.reuters.com/article/us-bayer-monsanto-france/french-court-cancels-monsanto-weedkiller-permit-on-safety-grounds-idUSKCN1P91F6}}</ref>

A vote on the relicensing of glyphosate in the EU stalled in March 2016. Member states France, Sweden, and the Netherlands objected to the renewal.<ref>{{cite news|url=https://www.theguardian.com/environment/2016/mar/08/eu-vote-on-controversial-weedkiller-licence-postponed-glyphosate|title=Vote on controversial weedkiller's European licence postponed|author=Arthur Nelson|newspaper=The Guardian|date=2016-03-08}}</ref> A vote to reauthorize on a temporary basis failed in June 2016<ref>{{cite news|url=https://www.theguardian.com/environment/2016/jun/06/recall-of-monsantos-roundup-likely-as-eu-refuses-limited-use-of-glyphosate|title=Recall of Monsanto's Roundup likely as EU refuses limited use of glyphosate|agency=Reuters|date=2016-06-06}}</ref> but at the last minute the license was extended for 18 months until the end of 2017.<ref>{{cite news|url=https://www.theguardian.com/business/2016/jun/29/controversial-chemical-roundup-weedkiller-escapes-immediate-ban|title=Controversial chemical in Roundup weedkiller escapes immediate ban|author=Arthur Nelson|newspaper=[[The Guardian]]|date=2016-06-29}}</ref>

On 27 November 2017, in the [[Council of the European Union|EU Council]] a majority of eighteen member states voted in favor of permitting the use of glyphosate for five more years. A [[Voting in the Council of the European Union|qualified majority]] of sixteen states representing 65% of EU citizens was required to pass the law.<ref>
[https://www.nrc.nl/nieuws/2017/11/28/roundup-omstreden-bestrijdingsmiddel-glyfosaat-blijft-nog-zeker-vijf-jaar-te-gebruiken-in-eu-14259800-a1582828 'EU votes for five more years usage of herbicide glyphosate']. ''[[NRC Handelsblad]]'' {{in lang|nl}}, 28 November 2017.</ref> The German Minister of Agriculture, [[Christian Schmidt (politician)|Christian Schmidt]], unexpectedly voted in favor while the German coalition government was internally divided on the issue which usually results in Germany abstaining.<ref>[https://www.nrc.nl/nieuws/2017/11/28/gesprek-cdu-spd-onder-druk-door-onkruidverdelger-a1582937 'Talks CDU-SPD under pressure because of herbicide'] {{in lang|nl}}. ''[[NRC Handelsblad]]'', 28 November 2017.</ref>

In December 2018, attempts were made to reopen the decision to license the weed-killer. These were condemned by Conservative MEPs, who said the proposal was politically motivated and flew in the face of scientific evidence.<ref>{{cite news |title= Move to re-open Glyphosate case attacked by Conservative MEPs |url= http://conservativeeurope.com/news/move-to-re-open-glyphosate-case-attacked-by-conservative-meps |work= Conservative Europe |date= 6 December 2018 |access-date= January 30, 2019 |archive-date= January 30, 2019 |archive-url= https://web.archive.org/web/20190130162344/http://conservativeeurope.com/news/move-to-re-open-glyphosate-case-attacked-by-conservative-meps |url-status= dead }}</ref>

In March 2019, the [[European Court of Justice]] (ECJ) ordered the [[European Food Safety Authority]] (EFSA) to release all carcinogenicity and toxicity pesticide industry studies on glyphosate to the general public.<ref>[https://sustainablepulse.com/2019/03/07/european-court-of-justice-orders-eu-regulators-to-publicly-release-secret-industry-glyphosate-studies/ ‘European Court of Justice orders public release of industry glyphosate studies’], 7 March 2019.</ref>

In March 2019, the [[States of Austria|Austrian state]] of [[Carinthia]] outlawed the private use of glyphosate in residential areas while the commercial application of the herbicide is still permitted for farmers. The use of glyphosate by public authorities and road maintenance crews was already halted a number of years prior to the current ban by local authorities.<ref>[https://diepresse.com/home/wirtschaft/economist/5598237/Kaernten-verbietet-ab-28-Maerz-Glyphosat-fuer-Private "Kärnten verbietet ab 28. März Glyphosat für Private"] (in German). ''Die Presse''. Retrieved 29 April 2019.</ref>

In June 2019, [[Deutsche Bahn]] and [[Swiss Federal Railways]] announced that glyphosate and other commonly used herbicides for weed eradication along railway tracks will be phased out by 2025, while more environmentally sound methods for vegetation control are implemented.<ref>Briner M (July 2018). [https://www.aargauerzeitung.ch/wirtschaft/schluss-mit-glyphosat-sbb-wollen-unkraut-anders-vernichten-132845313 Schluss mit Glyphosat: SBB wollen Unkraut anders vernichten] {{Webarchive|url=https://web.archive.org/web/20190627064202/https://www.aargauerzeitung.ch/wirtschaft/schluss-mit-glyphosat-sbb-wollen-unkraut-anders-vernichten-132845313 |date=June 27, 2019 }} ''Aargauer Zeitung'' (in German). Retrieved 26 June 2019.</ref><ref>Schlesiger Ch (June 2019). [https://www.wiwo.de/unternehmen/dienstleister/unkrautvernichter-deutsche-bahn-will-kuenftig-auf-glyphosat-verzichten-/24456436.html Deutsche Bahn will künftig auf Glyphosat verzichten] ''Wirtschaftswoche'' (in German). Retrieved 26 June 2019.</ref>

In July 2019, the [[Austria]]n parliament voted to ban glyphosate in Austria.<ref name=a-report-constitution-water-public>[https://orf.at/stories/3128905/ Nationalrat stimmt für Glyphosatverbot], Austrian parliament votes to forbid Glyphosphat & water is a public good necessary for the existence of a human, orf.at, 2019-07-02</ref>

In September 2019, the German Environment Ministry announced that the use of glyphosate will be banned from the end of 2023. The use of glyphosate-based herbicides will be reduced starting from 2020.<ref>{{cite news |last1=Rinke |first1=Andreas |title=Germany to ban use of glyphosate from end of 2023 |url=https://www.reuters.com/article/us-germany-glyphosate/germany-to-ban-use-of-glyphosate-from-end-of-2023-sources-idUSKCN1VP0TY |work=[[Reuters]]|date=September 4, 2019}}</ref>

The assessment process for an approval of glyphosate in the European Union will begin in December 2019. France, Hungary, the Netherlands and Sweden will jointly assess the application dossiers of the producers. The draft report of the assessment group will then be peer-reviewed by the EFSA before the current approval expires in December 2022.<ref>{{cite web |last1=European Commission |title=Glyphosate Current status of glyphosate in the EU |url=https://ec.europa.eu/food/plant/pesticides/glyphosate_en |access-date=October 29, 2019|date=July 12, 2017 }}</ref>

The date has since been pushed back, partially due to very high interest and input in the participation process, with the [[European Food Safety Authority]] (EFSA) even calling it an “unprecedented number”.<ref>{{Cite web |date=10 May 2022 |title=Glyphosate: EFSA and ECHA update timelines for assessments |url=https://www.efsa.europa.eu/en/news/glyphosate-efsa-and-echa-update-timelines-assessments |access-date=28 May 2022 |website=European Food Safety Authority}}</ref> Because the EFSA has to review all these 2400 comments and almost 400 responses, the process is expected to take longer. The created document is under extra review by the specially formed Glyphosate Renewal Group (GRG) and the Assessment Group on Glyphosate (AGG), the panel consisting of the four mentioned member states. With their responses now being scheduled for September 2022, the consultations with member states are supposed to be held by the very end of 2022.<ref>{{Cite web |date=11 May 2022 |title=Glifosato: La EFSA pospone su evaluacion ante la avalancha de comentarios recibidos |url=https://www.agrodigital.com/2022/05/11/glifosato-la-efsa-pospone-su-evaluacion-ante-la-avalancha-de-comentarios-recibidos/ |access-date=28 May 2022 |website=Agrodigital}}</ref><ref>{{Cite web |last=Case |first=Philip |date=11 May 2022 |title=EU delays glyphosaterenewal decision until 2023 |url=https://www.fwi.co.uk/news/farm-policy/eu-delays-glyphosate-renewal-decision-until-2023 |access-date=28 May 2022 |website=Farmers Weekly}}</ref> This would allow to finish the final assessment by mid-2023 and pass it on to further legislature to decide.

In November 2023, glyphosate received 10 year renewed authorization for use in the EU.<ref>{{Cite web |date=2023-11-16 |title=No qualified majority reached by Member States to renew or reject the approval of glyphosate |url=https://ec.europa.eu/commission/presscorner/detail/en/statement_23_5792 |access-date=2023-11-16 |website=European Commission |language=en}}</ref>

===Other countries===
In September 2013, the [[Legislative Assembly of El Salvador]] approved legislation to ban 53 agrochemicals, including glyphosate; the ban on glyphosate was set to begin in 2015.<ref>Staff, Centralamericadata.com. September 6, 2013 [http://en.centralamericadata.com/en/article/home/El_Salvador_Use_of_53_Chemicals_Banned El Salvador: Use of 53 Chemicals Banned]</ref><ref>Staff, Centralamericadata.com. November 27, 2013 [http://en.centralamericadata.com/en/article/home/El_Salvador_Confirmation_to_Be_Given_on_Ban_of_Agrochemicals El Salvador: Confirmation to Be Given on Ban of Agrochemicals]</ref><ref>Legislative Assembly of El Salvador.  November 26, 2013
[http://www.asamblea.gob.sv/noticias/archivo-de-noticias/analizan-observaciones-del-ejecutivo-al-decreto-que-contiene-la-prohibicion-de-53-agroquimicos-que-danan-la-salud/ Analizan observaciones del Ejecutivo al decreto que contiene la prohibición de 53 agroquímicos que dañan la salud] {{Webarchive|url=https://web.archive.org/web/20150531075642/http://www.asamblea.gob.sv/noticias/archivo-de-noticias/analizan-observaciones-del-ejecutivo-al-decreto-que-contiene-la-prohibicion-de-53-agroquimicos-que-danan-la-salud |date=May 31, 2015 }} [https://translate.google.com/translate?sl=auto&tl=en&js=y&prev=_t&hl=en&ie=UTF-8&u=http%3A%2F%2Fwww.asamblea.gob.sv%2Fnoticias%2Farchivo-de-noticias%2Fanalizan-observaciones-del-ejecutivo-al-decreto-que-contiene-la-prohibicion-de-53-agroquimicos-que-danan-la-salud%2F&edit-text= English translation by Google]</ref>

In the [[United States]], the state of [[Minnesota]] preempts local laws that attempt to ban glyphosate. In 2015 there was an attempt to pass legislation at the state level that would repeal that preemption.<ref name="Minnea-StPaul-glyph-res">{{cite web | first1=Robyn | last1=Moore | title=Herbicide a growing problem | website=[[The Citizen (Minneapolis-Saint Paul)|The Citizen]] | publisher=[[Press Publications]] | date=2021-08-08 | url=http://www.presspubs.com/citizen/news/herbicide-a-growing-problem/article_09362c4a-e475-11e4-8a7b-7b5484fd9d09.html | access-date=2021-08-09}}</ref>

In May 2015, the [[President of Sri Lanka]] banned the use and import of glyphosate, effective immediately.<ref>Staff, Colombo Page. May 22, 2015 [http://www.colombopage.com/archive_15B/May22_1432308620CH.php Sri Lankan President orders to ban import of glyphosate with immediate effect] {{Webarchive|url=https://web.archive.org/web/20150630213502/http://www.colombopage.com/archive_15B/May22_1432308620CH.php |date=June 30, 2015 }}</ref><ref>Sarina Locke for the Australian Broadcasting Corporation. Updated May 27, 2015 [http://www.abc.net.au/news/2015-05-27/toxicologist-worries-glyphosate-ban-based-on-bad-science/6500720 Toxicologist critical of 'dodgy science' in glyphosate bans]</ref> However, in May 2018 the Sri Lankan government decided to re-authorize its use in the plantation sector.<ref>{{cite web | title = Glyphosate ban lifted for tea, rubber industries: Navin | url = http://www.dailymirror.lk/article/Glyphosate-ban-lifted-for-tea-rubber-industries-Navin-149402.html | work = Daily Mirror  | date = 2018-05-02 }}</ref>

In May 2015, [[Bermuda]] blocked importation on all new orders of glyphosate-based herbicides for a temporary suspension awaiting outcomes of research.<ref name=Bermuda1>{{cite news | title = Health Minister: importation of roundup weed spray suspended | url = http://www.todayinbermuda.com/news/health/item/1471-health-minister-importation-of-roundup-weed-spray-suspended | publisher = Bermuda Today | date = 11 May 2015 | archive-url = https://web.archive.org/web/20150602094518/http://www.todayinbermuda.com/news/health/item/1471-health-minister-importation-of-roundup-weed-spray-suspended | archive-date = June 2, 2015 | url-status = dead }}</ref>

In May 2015, [[Colombia]] announced that it would stop using glyphosate by October 2015 in the destruction of illegal plantations of [[coca]], the raw ingredient for [[cocaine]].  Farmers have complained that the aerial fumigation has destroyed entire fields of [[coffee]] and other legal produce.<ref name="BBCColumbia" />

In April 2019, [[Vietnam]]'s Ministry of Agriculture and Rural Development banned the use of glyphosate throughout the country.<ref name=Vietnam>{{cite news | title = Việt Nam bans weed killer ingredient glyphosate | url = http://vietnamnews.vn/society/518568/viet-nam-bans-weed-killer-ingredient-glyphosate.html | publisher = Viet Nam News | date = 11 April 2019}}</ref>

In August 2020, [[Mexico|Mexican]] President [[Andrés Manuel López Obrador]] announced that glyphosate will be gradually phased out of use in Mexico by late 2024.<ref>{{cite web |title=Mexico to phase out use of herbicide glyphosate |url=https://www.reuters.com/article/us-mexico-herbicide-idUSKCN25902N |website=Reuters |access-date=3 March 2021 |date=13 August 2020}}</ref>

Thailand's National Hazardous Substances Committee decided to ban the use of glyphosate in October 2019<ref>Reuters (October 25, 2019). [https://www.reuters.com/article/us-thailand-chemicals-usa/u-s-protests-thailands-chemical-ban-would-hurt-crop-exports-idUSKBN1X41JQ U.S. protests Thailand's chemical ban would hurt crop exports]</ref> but reversed the decision in November 2019.<ref>{{cite news |title=Thailand reverses ban of chemicals use in pesticides |url=https://www.reuters.com/article/us-thailand-chemicals/thailand-reverses-ban-of-chemicals-use-in-pesticides-idUSKBN1Y1128 |access-date=12 December 2019 |work=Reuters |date=27 November 2019 |language=en}}</ref>

After a court-ruling in 2018, glyphosate was temporarily banned in [[Brazil]]. This decision was later overturned, causing major criticism by the federal agency of health ([[Brazilian Health Regulatory Agency|Anvisa]]). This comes, as the latest evaluations declared glyphosate as noncarcinogenic. Since all carcinogenic agrichemicals are automatically banned in the country, this allowed the continuous use.<ref>{{Cite web |last=Spring |first=Jake |date=26 February 2019 |title=Brazil health officials find weed-killer glyphosate non-cancerous |url=https://www.reuters.com/article/us-brazil-agriculture-glyphosate-idUSKCN1QF1J1 |access-date=28 May 2022 |website=Reuters}}</ref>

In New Zealand, glyphosate is an approved herbicide for killing weeds,<ref name="mpi-nz" /> with the most popular brand being [[Roundup (herbicide)|Roundup]].<ref name="mpi-nz">{{Cite web|url=https://www.mpi.govt.nz/food-safety-home/safe-levels-of-chemicals-in-food/fertilisers-pesticides-hormones-and-medicines-in-food/glyphosate-in-food/|title=Glyphosate in food &#124; MPI - Ministry for Primary Industries. A New Zealand Government Department.|first=Ministry for Primary|last=Industries|website=www.mpi.govt.nz|date=July 13, 2021 }}</ref><ref name="epa-nz">{{Cite web|url=https://www.epa.govt.nz/everyday-environment/gardening-products/glyphosate/|title=Glyphosate &#124; EPA|website=www.epa.govt.nz}}</ref> Genetically modified crops designed to resist glyphosate are absent in New Zealand.<ref name="mpi-nz" /> Crops applied with glyphosate must be regulated under the HSNO Act 1996 and ACVM Act 1997.<ref name="mpi-nz" /><ref name="govtepa-pdf-nz">{{cite web|url=https://www.epa.govt.nz/assets/Uploads/Documents/Hazardous-Substances/Glyphosate-call-for-information/Glyphosate-call-for-information-summary-report-may22.pdf |title=Glyphosate in Aotearoa New Zealand |date=11 May 2022 |last=New Zealand Government}}</ref> Legal status for glyphosate use in New Zealand is approved for commercial and personal use.<ref name="epa-nz" /> In 2021, exports of New Zealand honey were found to contain traces of glyphosate, causing some concern to Japanese importers.<ref name="honey-nz-shun">{{Cite web|url=https://www.rnz.co.nz/news/country/434807/japan-warns-it-will-block-nz-honey-shipments-if-glyphosate-limits-breached|title=Japan warns it will block NZ honey shipments if glyphosate limits breached|date=January 20, 2021|website=RNZ}}</ref><ref name="honey-nz-shun2">{{Cite web|url=https://thespinoff.co.nz/business/01-06-2021/glyphosate-is-farmings-favourite-weed-killer-can-nz-learn-to-live-without-it|title=Glyphosate is farming's favourite weed killer. Can NZ learn to live without it?|first=Nick|last=Stringer|date=June 1, 2021|website=The Spinoff}}</ref>

==Legal cases==
{{See also|Monsanto legal cases#Roundup}}
===Lawsuits claiming liability for cancer===
Since 2018, in a number of court cases in the United States, plaintiffs have argued that their cancer was caused by exposure to glyphosate in glyphosate-based herbicides produced by Monsanto/Bayer. Defendant Bayer has paid out over $9.6 billion in judgements and settlements in these cases. Bayer has also won at least 10 cases, successfully arguing that their glyphosate-based herbicides were not responsible for the plaintiff's cancer.<ref name=bayer-wins>{{Cite web |date=December 23, 2023 |title=Bayer wins latest Roundup cancer trial, ending losing streak |url=https://www.reuters.com/legal/bayer-wins-latest-roundup-cancer-trial-ending-losing-streak-2023-12-23/ |website=Reuters}}</ref>

===Advertising controversies===
In 2016, a lawsuit was filed against [[Quaker Oats]] in the [[United States district court|Federal district courts]] of both [[New York (state)|New York]] and [[California]] after trace amounts of glyphosate were found in [[oatmeal]]. The lawsuit alleged that the claim of "100% natural" was [[false advertising]].<ref>{{Cite news| issn = 0362-4331| last = Strom| first = Stephanie| title = Quaker Oats' 100% Natural Claim Questioned in Lawsuit| work = The New York Times| access-date = 2018-08-13| date = 2017-12-21| url = https://www.nytimes.com/2016/05/02/business/quaker-oats-100-natural-claim-questioned-in-lawsuit.html}}</ref> That same year [[General Mills]] dropped the label "Made with 100% Natural Whole Grain Oats" from their [[Nature Valley]] [[granola bars]] after a lawsuit was filed that claimed the [[oat]]s contained trace amounts of glyphosate.<ref>{{Cite web| title = General Mills drops '100% Natural' on Nature Valley granola bars after lawsuit| work = USA Today| access-date = 2018-08-25| url = https://www.usatoday.com/story/money/nation-now/2018/08/24/general-mills-drops-100-percent-natural-nature-valley/1082709002/}}</ref>

===Trade dumping allegations===
United States companies have cited trade issues with glyphosate being [[Dumping (pricing policy)|dumped]] into western world market areas by Chinese companies, and a formal dispute was filed in 2010.<ref name="urlwww.usitc.gov">{{cite web | url = https://www.usitc.gov/trade_remedy/731_ad_701_cvd/investigations/2010/Glyphosate%20from%20China/Preliminary/conference_04-22-2010.pdf | title = In the Matter of: Glyphosate From China | date = 2010-04-22 | publisher = United States International Trade Commission }}</ref><ref>{{cite news |last1=Hoskins |first1=Tim |title=Glyphosate maker complains of Chinese dumping |url=https://agupdate.com/iowafarmertoday/news/state-and-regional/glyphosate-maker-complains-of-chinese-dumping/article_b260291c-1d8d-56a9-8fd3-d460c89c8565.html |access-date=29 December 2023 |publisher=Iowa Farmer Today |date=15 April 2010}}</ref>

== Misinformation campaigns ==
Glyphosate has become a locus of campaigning and misinformation by anti-GMO activists because of its association with genetically-modified glyphosate-resistant crops.<ref name=bogey>{{cite web |publisher=[[Science-Based Medicine]] |first=Bellamy |last=Jann |title=Monsanto gets injunction against California's mandated cancer warning for glyphosate |date=20 July 2020 |url=https://sciencebasedmedicine.org/monsanto-gets-injunction-against-californias-mandated-cancer-warning-for-glyphosate/}}</ref> 

The US politician [[Robert F. Kennedy Jr.]] has incorporated glyphosate into his [[anti-vaccination]] rhetoric, falsely claiming that both glyphosate and vaccines may be contributing to the American [[obesity epidemic]].<ref name=bogey/> [[Stephanie Seneff]] has also falsely claimed that it may have a role in [[autism]] and in worsening [[concussion]].<ref name=ss>{{cite web |publisher=[[Science-Based Medicine]] |vauthors=Gorski DH |title=Quoth RFK Jr.: Vaccines and glyphosate are responsible for the obesity epidemic! |date=24 February 2020 |url=https://sciencebasedmedicine.org/quoth-rfk-jr-vaccines-and-glyphosate-are-responsible-for-the-obesity-epidemic/}}</ref>

==See also==
{{div col|colwidth=20em|small=yes}}
* [[2,4-Dichlorophenoxyacetic acid]]
* [[Ammonium sulfamate]]
* [[Atrazine]]
* [[Environmental impact of pesticides]]
* [[Health effects of pesticides]]
* [[Integrated pest management]]
* [[Monsanto legal cases]]
* [[Pesticide regulation in the United States]]
* [[Regulation of pesticides in the European Union]]
* [[Séralini affair]]
{{div col end}}

==References==
{{Reflist}}

==External links==

{{Commons category}}
* {{PPDB|373|Name=Glyphosate}}
* {{PPDB|1062|Name=Glyphosate trimesium}}
* {{PPDB|2395|Name=Glyphosate, isopropylamine salt}}
* {{PPDB|2396|Name=Glyphosate, potassium salt}}

{{Herbicides}}
{{Authority control}}

[[Category:Herbicides]]
[[Category:Acetic acids]]
[[Category:Amines]]
[[Category:Phosphonic acids]]
[[Category:Monsanto]]
[[Category:IARC Group 2A carcinogens]]
[[Category:Chelating agents]]
[[Category:Secondary amino acids]]

[[Category:Systemic herbicides]]