Metam sodium: Difference between revisions

| verifiedrevid = 409002120

| Reference = <ref name="Merck">''[[Merck Index]]'', 11th Edition, '''5860'''.</ref>

| ImageFile = metham sodium.png

| ImageSize = 160px

| ImageFile1 = Metham sodium 3D ball.png

| ImageSize1 = 170

| ImageAlt1 = Ball-and-stick model of the component ions of metham sodium

| PIN = Sodium methylcarbamodithioate

| OtherNames = Metham sodium<br>Carbathion<br>Carbathione<br>Carbothion<br>Metamsodium<br>Metam-sodium

| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}

| CASNo_Ref = {{cascite|correct|CAS}}

| UNII_Ref = {{fdacite|correct|FDA}}

| UNII = 3CD7UKN224

| PubChem = 5366415

| SMILES = [Na+].[S-]C(=S)NC

}}

| Formula=C₂H₄NNaS₂

| MolarMass=129.18 g/mol

| Appearance=

| Density=

| MeltingPt=

| BoilingPt=

| Solubility=

| MainHazards=

| FlashPt=

| AutoignitionPt =

'''Metam sodium''' is an [[organosulfur compound]] with the formula {{chem2|CH3NHCS2Na}}. The compound is a sodium salt of a [[dithiocarbamate]]. The compound exists as a colorless dihydrate, but most commonly it is encountered as an aqueous solution.<ref name=Ullmann>{{cite book |doi=10.1002/14356007.a17_125.pub2|chapter=Nematicides |title=Ullmann's Encyclopedia of Industrial Chemistry |year=2008 |last1=Hartwig |first1=Jürgen |last2=Sommer |first2=Herbert |last3=Müller |first3=Franz |isbn=978-3527306732 }}</ref> It is used as a soil [[fumigant]], [[pesticide]], [[herbicide]], and [[fungicide]]. It is one of the most widely used pesticides in the United States, with approximately 60 million pounds used in 2001.<ref>[http://www.epa.gov/oppbead1/pestsales/01pestsales/usage2001_2.htm 2000-2001 Pesticide Market Estimates] {{webarchive|url=https://web.archive.org/web/20090207095013/http://www.epa.gov/oppbead1/pestsales/01pestsales/usage2001_2.htm |date=2009-02-07 }}, U.S. Environmental Protection Agency</ref>

==Preparation and properties==

Metam sodium is prepared by combining [[methylamine]], [[carbon disulfide]], and [[sodium hydroxide]]:<ref name=Ullmann/>

:{{chem2|CH3NH2 + CS2 + NaOH → CH3NHCS2Na + H2O}}

It also arises from the reaction of [[methyl isothiocyanate]] and [[sodium thiolate]].<ref name="Merck"/>

Upon exposure to the environment, metam sodium decomposes to [[methyl isothiocyanate]] and other sulfur compounds.<ref name="pmid21740140">{{cite journal| author=Bretaudeau Deguigne M, Lagarce L, Boels D, Harry P| title=Metam sodium intoxication: the specific role of degradation products--methyl isothiocyanate and carbon disulphide--as a function of exposure. | journal=Clin Toxicol (Phila) | year= 2011 | volume= 49 | issue= 5 | pages= 416–22 | pmid=21740140 | doi=10.3109/15563650.2011.585472 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=21740140 }} </ref>

==Safety and environmental considerations==

Metam sodium is nonpersistent in the environment since it decomposes rather quickly to toxic [[methyl isothiocyanate]] and [[carbon disulfide]].<ref name="pmid21740140">{{cite journal| author=Bretaudeau Deguigne M, Lagarce L, Boels D, Harry P| title=Metam sodium intoxication: the specific role of degradation products--methyl isothiocyanate and carbon disulphide--as a function of exposure. | journal=Clin Toxicol (Phila) | year= 2011 | volume= 49 | issue= 5 | pages= 416–22 | pmid=21740140 | doi=10.3109/15563650.2011.585472 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=21740140 }} </ref> In 1991 a [[Southern Pacific Transportation Company#Notable accidents|tank car with 19,000 gallons of a metam sodium based pesticide spilled]] into [[Sacramento River]] above [[Lake Shasta]]. This killed all fish in a 41-mile stretch of the river. 20 years later the [[rainbow trout]] population had recovered.<ref>{{Cite web|url=https://dtsc.ca.gov/20th-anniversary-of-largest-chemical-spill-in-california-history/|title=Largest chemical spill in California history|website=dtsc.ca.gov|language=en|access-date=2017-12-11}}</ref>

==See also==

* [[Zineb]] - A related [[dithiocarbamate]] salt which is also used as a fungicide

==External links==

* {{PPDB|447}}

[[Category:Organic sodium salts]]