Acrylamide

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Acrylamide
Acrylamide-2D-skeletal.png Acrylamide-MW-2000-3D-balls.png
Acrylamide-MW-2000-3D-vdW.png
Identifiers
CAS number 79-06-1 YesY
PubChem 6579
ChemSpider 6331 YesY
UNII 20R035KLCI YesY
KEGG C01659 YesY
ChEBI CHEBI:28619 YesY
ChEMBL CHEMBL348107 YesY
Jmol-3D images Image 1
Image 2
Properties
Molecular formula C3H5NO
Molar mass 71.08 g mol−1
Density 1.13 g/cm3
Melting point 84.5 °C (184.1 °F; 357.6 K)
Boiling point None (polymerization)
Solubility in water 2.04 kg/L (25 °C)
Hazards
MSDS ICSC 0091
GHS pictograms GHS-pictogram-skull.svgGHS-pictogram-silhouete.svg[1]
GHS hazard statements H301, H312, H315, H317, H319, H332, H340, H350, H361, H372[1]
GHS precautionary statements P201, P280, P301+310, P305+351+338, P308+313[1]
EU Index 616-003-00-0
EU classification Toxic (T)
Carc. Cat. 2
Muta. Cat. 2
Repr. Cat. 3
R-phrases R45, R46, R20/21,
R25, R36/38, R43,
R48/23/24/25, R62
S-phrases S53, S45
NFPA 704
Flammability code 2: Must be moderately heated or exposed to relatively high ambient temperature before ignition can occur. Flash point between 38 and 93 °C (100 and 200 °F). E.g., diesel fuel Health code 3: Short exposure could cause serious temporary or residual injury. E.g., chlorine gas Reactivity code 2: Undergoes violent chemical change at elevated temperatures and pressures, reacts violently with water, or may form explosive mixtures with water. E.g., phosphorus Special hazards (white): no codeNFPA 704 four-colored diamond
Autoignition temperature 424 °C (795 °F; 697 K)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 YesY (verify) (what is: YesY/N?)
Infobox references

Acrylamide (or acrylic amide) is a chemical compound with the chemical formula C3H5NO. Its IUPAC name is prop-2-enamide. It is a white odorless crystalline solid, soluble in water, ethanol, ether, and chloroform. Acrylamide decomposes in the presence of acids, bases, oxidizing agents, iron, and iron salts. It decomposes non-thermally to form ammonia, and thermal decomposition produces carbon monoxide, carbon dioxide, and oxides of nitrogen.

Acrylamide is prepared on an industrial scale by the hydrolysis of acrylonitrile by nitrile hydratase.

Most acrylamide is used to synthesize polyacrylamides, which find many uses as water-soluble thickeners. These include use in wastewater treatment, gel electrophoresis (SDS-PAGE), papermaking, ore processing, tertiary oil recovery, and the manufacture of permanent press fabrics. Some acrylamide is used in the manufacture of dyes and the manufacture of other monomers.

The discovery of acrylamide in some cooked starchy foods in 2002 prompted concerns about the carcinogenicity of those foods. As of 2014 acrylamide is still in debate for its carcinogenicity links in humans.[2]

Uses[edit]

Molecular biology laboratories[edit]

Polyacrylamide was first used in a laboratory setting in the early 1950s. In 1959, the groups of Davis and Ornstein[3] and of Raymond and Weintraub[4] independently published on the use of polyacrylamide gel electrophoresis to separate charged molecules.[5] The technique is widely accepted today, and remains a common protocol in molecular biology labs.

Acrylamide has many other uses in molecular biology laboratories, including the use of linear polyacrylamide (LPA) as a carrier, which aids in the precipitation of small amounts of DNA. Many laboratory supply companies sell LPA for this use.[6]

Other uses[edit]

The majority of acrylamide is used to manufacture various polymers.[7][8] In the 1970s and 1980s, the proportionately largest use of these polymers was in water treatment.[9] Additional uses include as binding, thickening or flocculating agents in grout, cement, sewage/wastewater treatment, pesticide formulations, cosmetics, sugar manufacturing, soil erosion prevention, ore processing, food packaging, and plastic products.[7] Polyacrylamide is also used in some potting soil.[7]

Toxicity and carcinogenicity[edit]

Some evidence suggests exposure to large doses can cause damage to the male reproductive glands.

Acrylamide is considered a potential occupational carcinogen by U.S. government agencies. The Occupational Safety and Health Administration and the National Institute for Occupational Safety and Health have set dermal occupational exposure limits at 0.03 mg/m3 over an eight-hour workday.[10]

Occurrence in food and associated health risks[edit]

Discovery of acrylamide in foods[edit]

Acrylamide has been found to occur in many cooked starchy foods and is of concern as a possible carcinogen.[11] Acrylamide was discovered accidentally in foods in April 2002 by scientists in Sweden when they found the chemical in starchy foods, such as potato chips (potato crisps), French fries, and bread that had been heated higher than 120 °C (248 °F) (production of acrylamide in the heating process was shown to be temperature-dependent).[11] It was not found in food that had been boiled[11][12] or in foods that were not heated.[11]

Acrylamide levels appear to rise as food is heated for longer periods of time. although researchers are still unsure of the precise mechanisms by which acrylamide forms in foods, many[13] believe it is a byproduct of the Maillard reaction. In fried or baked goods, acrylamide may be produced by the reaction between asparagine and reducing sugars (fructose, glucose, etc.) or reactive carbonyls at temperatures above 120 °C (248 °F).[14][15]

Later studies have found acrylamide in black olives,[16] prunes,[17] dried pears,[17] and coffee.[18]

Acrylamide also is found in cocoa powder and chocolate, formed during cacao bean roasting.[19]

Estimates for the proportion of acrylamide in adult diets coming from the consumption of coffee range from 20 to 40%; prune juice has a high concentration of acrylamide, although adults consume it in far smaller quantities.[20] Acrylamide also is found in cocoa powder, roasted almonds, whole wheat bread, and Pringles.[21]

The FDA has analyzed a variety of U.S. food products for levels of acrylamide since 2002.[22]

A 72-hour study of urine from six young healthy volunteers who had consumed a meal containing 0.94 mg of acrylamide concluded, "most of the acrylamide ingested with food is absorbed in humans".[23]

It is possible to inhibit the formation of acrylamide with the use of an enzyme treatment prior to applying heat to the food. This is done in the food industry by potato chip and french fry manufacturers, coffee roasters, and some other manufacturers of cooked foods.

Acrylamide toxicity from food exposure[edit]

Although acrylamide has known toxic effects on the nervous system and on fertility, a June 2002 report by the Food and Agriculture Organization of the United Nations and the World Health Organization concluded the intake level required to observe neuropathy (0.5 mg/kg body weight/day) was 500 times higher than the average dietary intake of acrylamide (1 μg/kg body weight/day). For effects on fertility, the level is 2,000 times higher than the average intake.[24] From this, they concluded acrylamide levels in food were safe in terms of neuropathy, but raised concerns over human carcinogenicity based on known carcinogenicity in laboratory animals.[24]

Human cancer risk of acrylamide exposure from food[edit]

Acrylamide causes cancer in rats when administered orally in high-dose experiments, increasing tumors in the nervous system, oral cavity, peritoneum, thyroid gland, mammary gland, uterus, and clitoris.[25] There is a margin of 900-fold between the dose that gave cancer to 10% of rats and human exposure to acrylamide in the diet.[26]

To determine the human cancer risk from acrylamide, several studies have been conducted using food frequency data to estimate acrylamide intake and its effect on cancer risk. A Swedish study using 1,525 patients failed to find a link between acrylamide in food and liver, kidney, and bowel cancers.[27] A larger Swedish study on 45,306 men also found no link between dietary intake of acrylamide and risk for colorectal cancer.[28] A large Italian study covering 1991–2000 in Italy and Switzerland analyzed the risk of cancer of the oral cavity and pharynx, esophagus, larynx, large bowel, breast, and ovaries from consumption of fried or baked potatoes, and found no association.[29] A 2005 study of 43,404 Swedish women in the Women's Lifestyle and Health Cohort found that the women's greatest sources of acrylamide were from coffee (54% of intake), fried potatoes (12% of intake), and crisp bread (9% of intake), but found no association between breast cancer risk and higher intake of any specific foods.[18] A 2009 Swedish follow-up study on 61,433 women also found no association between long-term dietary acrylamide intake and breast cancer.[30] Another 2009 study on 90,628 premenopausal women in the United States also found no relationship between dietary acrylamide intake and breast cancer risk.[31] A Dutch study on 62,573 women aged 55–69 years did find a link between acrylamide intake and increased risks of postmenopausal endometrial and ovarian cancer after adjusting for smoking, but not with breast cancer.[32]

Although only one of these studies found an association between dietary acrylamide and cancer, it has been pointed out that food frequency questionnaires do not give a very precise measure of exposure to acrylamide.[33] A 2008 study using blood acrylamide levels after adjusting for smoking did find a 2.7-fold increase in risk for estrogen receptor-positive breast cancer for every tenfold increase of acrylamide.[34]

Opinions of health organizations[edit]

The World Health Organization (WHO) has set up a clearinghouse for information about acrylamide that includes a database of researchers and data providers; references for research published elsewhere; information updates about the current status of research efforts; and updates on information relevant to the health risk of acrylamide in food.[35]

One question the site's FAQ addresses is whether there can be an acceptable level of acrylamide in food. The WHO states that "Acrylamide belongs to the group of chemicals thought to have no reliably identifiable 'threshold' of effects, meaning that very low concentrations will also result in very low risks, but not in zero risk: Some risk is always present when the chemical is ingested. For these carcinogens, however, risk is thought to increase with increasing exposure. Very low risks (even of cancer), such as those that are less than one in one million, are considered to be acceptable to some consumers. To others this is unacceptable. The important pre-requisite for any decision is, however, a clear picture of the nature and level of the risk, as well as the potential for lowering this level. This clear picture does not exist for acrylamide at present." [36]

In February 2009, Health Canada announced that they were assessing whether acrylamide, which occurs naturally during the cooking of French fries, potato chips, and other processed foods, is a hazard to human health and whether any regulatory action needs to be taken. Currently, they are collecting information on the properties and prevalence of acrylamide in order to make their assessment.[37] In December 2009, after a positive reception from the food industry, Health Canada invited comment from the public on this proposal.[38] The European Chemical Agency added acrylamide to the list of substances of very high concern in March 2010.[39]

Heat-generated food toxicants (HEATOX) study[edit]

The Heat-generated Food Toxicants (HEATOX) Project was a European Commission-funded multidisciplinary research project running from late 2003 to early 2007. Its objectives were to "estimate health risks that may be associated with hazardous compounds in heat-treated food [, and to] find cooking/processing methods that minimize the amounts of these compounds, thereby providing safe, nutritious, and high-quality food-stuffs."[40][41] It found that "the evidence of acrylamide posing a cancer risk for humans has been strengthened,"[33] and that "compared with many regulated food carcinogens, the exposure to acrylamide poses a higher estimated risk to European consumers."[40] HEATOX sought also to provide consumers with advice on how to lower their intake of acrylamide, specifically pointing out that home-cooked food tends to contribute far less to overall acrylamide levels than food that was industrially prepared, and that avoiding overcooking is one of the best ways to minimize exposure at home.[40]

Public awareness[edit]

On April 24, 2002, the Swedish National Food Administration announced that acrylamide can be found in baked and fried starchy foods, such as potato chips, breads, and cookies. Concern was raised mainly because of the probable carcinogenic effects of acrylamide. This was followed by a strong, but short-lived, interest from the press. On 2005-08-26, California attorney general Bill Lockyer filed a lawsuit against four makers of french fries and potato chips – H.J. Heinz Co., Frito-Lay, Kettle Foods Inc., and Lance Inc. – to reduce the risk to consumers from consuming acrylamide.[42] The lawsuit was settled on 2008-08-01, with the food producers agreeing to cut acrylamide levels to 275 parts per billion in three years, to avoid a Proposition 65 warning label.[43] The companies avoided trial by agreeing to pay a combined $3 million in fines as a settlement with the California attorney general's office.[44]

In 2007, more than a hundred articles were written about acrylamide, according to Nexis and Factiva, including pieces in the Los Angeles Times,[45] the Boston Globe,[46] the Guardian,[47] and the Wall Street Journal, among others.

Occurrence in other products[edit]

Herbicides[edit]

Acrylamide may be a natural decay product of the polyacrylamide used as a thickening agent in some commercial herbicides. Lab tests have shown that heat and light can decompose polyacrylamide into acrylamide.[48]

Cigarettes[edit]

Cigarette smoking is a major acrylamide source.[49] It has been shown in one study to cause a three-fold greater increase in blood acrylamide levels than any dietary factor.[34]

See also[edit]

References[edit]

  1. ^ a b c Sigma-Aldrich Co., Acrylamide. Retrieved on 2013-07-20.
  2. ^ Xu, Y; Cui, B; Ran, R; Liu, Y; Chen, H; Kai, G; Shi, J (Apr 5, 2014). "Risk assessment, formation, and mitigation of dietary acrylamide: Current status and future prospects.". Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association 69C: 1–12. PMID 24713263. Retrieved 28 April 2014. 
  3. ^ Davis and Ornstein. Pipeline.com. Retrieved on 2012-06-11.
  4. ^ Raymond and Weintraub. Sciencemag.org (1959-09-18). Retrieved on 2012-06-11.
  5. ^ Reynolds S, Weintraub L. (1959). "Acrylamide Gel as a Supporting Medium for Zone Electrophoresis". Science 130 (3377): 711. doi:10.1126/science.130.3377.711. PMID 14436634. 
  6. ^ GenElute™-LPA from Sigma-Aldrich. biocompare.com
  7. ^ a b c Environment Canada and Health Canada (August 2009). "Screening Assessment for the Challenge: 2-Propenamide (Acrylamide)". Retrieved 20 June 2012. [dead link]
  8. ^ Office of Pollution Prevention and Toxics (September 1994). "II. Production, Use, and Trends" (plain text). Chemical Summary for Acrylamide (Report). United States Environmental Protection Agency. EPA 749-F-94-005a. http://www.epa.gov/chemfact/s_acryla.txt. Retrieved November 30, 2013.
  9. ^ "Polyacrylamide". Hazardous Substances Data Bank. United States National Library of Medicine. February 14, 2003. Consumption Patterns. CASRN: 9003-05-8. Retrieved November 30, 2013. 
  10. ^ Centers for Disease Control and Prevention (1994). "Documentation for Immediately Dangerous To Life or Health Concentrations (IDLHs) - Acrylamide". 
  11. ^ a b c d Tareke E; Rydberg P. et al. (2002). "Analysis of acrylamide, a carcinogen formed in heated foodstuffs". J. Agric. Food. Chem. 50 (17): 4998–5006. doi:10.1021/jf020302f. PMID 12166997. 
  12. ^ Food Standards Agency, Acrylamide: your questions answered [1] Retrieved on 2008-01-01
  13. ^ A Novel Technique for Limitation of Acrylamide Formation in Fried and Baked Corn Chips and in French Fries [2] Retrieved on 2012-07-13
  14. ^ Mottram DS, Wedzicha BL. and Dodson AT. (2002). "Acrylamide is formed in the Maillard reaction". Nature 419 (6906): 448–449. doi:10.1038/419448a. PMID 12368844. 
  15. ^ Chemistry World, Acrylamide cancer link confirmed [3] Retrieved on 2008-01-01
  16. ^ "Acrylamide detected in prune juice and olives" Food Safety & Quality Control Newsletter 26 March 2004, William Reed Business Media SAS, citing "Survey Data on Acrylamide in Food: Total Diet Study Results" United States Food and Drug Administration February 2004; later updated in June 2005, July 2006, and October 2006
  17. ^ a b Acrylamide in dried Fruits ETH Life (Swiss Federal Institute of Technology Zurich)
  18. ^ a b Mucci, LA; Sandin, S; Bälter, K; Adami, HO; Magnusson, C; Weiderpass, E (2005). "Acrylamide intake and breast cancer risk in Swedish women". JAMA: the Journal of the American Medical Association 293 (11): 1326–7. doi:10.1001/jama.293.11.1326. PMID 15769965. 
  19. ^ Michael Lustgarten (16 October 2011). "Acrylamide is in Chocolate! Another Reason Why Cooking Food at High Temperature is Not Good for You". Yahoo! Voices. Yahoo!. Retrieved 3 February 2014. 
  20. ^ Top Eight Foods by Acrylamide Per Portion. p. 17. jifsan.umd.edu (2004). Retrieved on 2012-06-11.
  21. ^ Acrylamide is in Chocolate. Retrieved on 2012-10-25
  22. ^ Survey Data on Acrylamide in Food: Individual Food Products. Fda.gov. Retrieved on 2012-06-11.
  23. ^ Fuhr, U.; Boettcher, MI; Kinzig-Schippers, M; Weyer, A; Jetter, A; Lazar, A; Taubert, D; Tomalik-Scharte, D; Pournara, P; Jakob, V; Harlfinger, S; Klaasaen, T; Berkessel, A; Angerer, J; Sörgel, F; Schömig, E (2006). "Toxicokinetics of Acrylamide in Humans after Ingestion of a Defined Dose in a Test Meal to Improve Risk Assessment for Acrylamide Carcinogenicity". Cancer Epidemiology Biomarkers & Prevention 15 (2): 266–71. doi:10.1158/1055-9965.EPI-05-0647. PMID 16492914. 
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  26. ^ Comparing Possible Cancer Hazards from Human Exposures to Rodent Carcinogens. Potency.berkeley.edu. Retrieved on 2012-06-11.
  27. ^ Mucci, L A; Dickman, P W; Steineck, G; Adami, H-O; Augustsson, K (2003). "Dietary acrylamide and cancer of the large bowel, kidney, and bladder: Absence of an association in a population-based study in Sweden". British Journal of Cancer 88 (1): 84–9. doi:10.1038/sj.bjc.6600726. PMC 2376776. PMID 12556964. 
  28. ^ Larsson, Susanna C.; Åkesson, Agneta; Bergkvist, Leif; Wolk, Alicja (2009). "Dietary acrylamide intake and risk of colorectal cancer in a prospective cohort of men". European Journal of Cancer 45 (4): 513–6. doi:10.1016/j.ejca.2008.12.001. PMID 19121931. 
  29. ^ Pelucchi, Claudio; Franceschi, Silvia; Levi, Fabio; Trichopoulos, Dimitrios; Bosetti, Cristina; Negri, Eva; La Vecchia, Carlo (2003). "Fried potatoes and human cancer". International Journal of Cancer 105 (4): 558–60. doi:10.1002/ijc.11118. PMID 12712450. 
  30. ^ Larsson, S. C.; Akesson, A.; Wolk, A. (2008). "Long-term Dietary Acrylamide Intake and Breast Cancer Risk in a Prospective Cohort of Swedish Women". American Journal of Epidemiology 169 (3): 376–81. doi:10.1093/aje/kwn319. PMID 19015201. 
  31. ^ Wilson, K. M.; Mucci, L. A.; Cho, E.; Hunter, D. J.; Chen, W. Y.; Willett, W. C. (2009). "Dietary Acrylamide Intake and Risk of Premenopausal Breast Cancer". American Journal of Epidemiology 169 (8): 954–61. doi:10.1093/aje/kwn421. PMC 2727226. PMID 19224978. 
  32. ^ Hogervorst, J. G.; Schouten, L. J.; Konings, E. J.; Goldbohm, R. A.; Van Den Brandt, P. A. (2007). "A Prospective Study of Dietary Acrylamide Intake and the Risk of Endometrial, Ovarian, and Breast Cancer". Cancer Epidemiology Biomarkers & Prevention 16 (11): 2304–13. doi:10.1158/1055-9965.EPI-07-0581. PMID 18006919. 
  33. ^ a b HEATOX project completed – brings new pieces to the Acrylamide Puzzle. (PDF) . Retrieved on 2012-06-11.
  34. ^ a b Olesen, PT; Olsen, A; Frandsen, H; Frederiksen, K; Overvad, K; Tjønneland, A (2008). "Acrylamide exposure and incidence of breast cancer among postmenopausal women in the Danish Diet, Cancer and Health Study". International Journal of Cancer. Journal International Du Cancer 122 (9): 2094–100. doi:10.1002/ijc.23359. PMID 18183576. 
  35. ^ Acrylamide, WHO
  36. ^ WHO|Frequently asked questions – acrylamide in food. Who.int (2010-12-10). Retrieved on 2012-06-11.
  37. ^ Health Canada: Acrylamide. Hc-sc.gc.ca. Retrieved on 2012-06-11.
  38. ^ "Do you want anti-cancer drug in junk food?". The Star (Toronto). 2009-12-22. Retrieved 2010-04-23. 
  39. ^ Candidate List of Substances of Very High Concern for authorisation. Echa.europa.eu. Retrieved on 2012-06-11.
  40. ^ a b c heat-Generated Food Toxicants; Identification, Characterisation and Risk Minimisation. (PDF) . Retrieved on 2012-06-11.
  41. ^ HEATOX, Heat-generated food toxicants: identification, characterisation and risk minimisation. (PDF) . Retrieved on 2012-06-11.
  42. ^ Attorney General Lockyer Files Lawsuit to Require Consumer Warnings About Cancer-Causing Chemical in Potato Chips and French Fries, Office of the attorney general, State of California, Department of justice
  43. ^ Lawsuit over potato chip ingredients settled Retrieved on 2008-08-02
  44. ^ "Settlement will reduce carcinogens in potato chips". Associated Press. Archived from the original on 2008-08-21. Retrieved 2008-08-02. 
  45. ^ KFC to tell diners of chemical in potatoes – Los Angeles Times. Latimes.com (2007-04-25). Retrieved on 2012-06-11.
  46. ^ Does a chemical formed in cooking french fries really cause cancer? – The Boston Globe. Boston.com (2007-09-24). Retrieved on 2012-06-11.
  47. ^ Atkins, Lucy (2007-12-04). "Is cooked food dangerous?". The Guardian (London). Retrieved 2010-04-23. 
  48. ^ Cummins, Joe (2002-08-01). "Acrylamide In Cooked Foods: The Glyphosate Connection". Institute of Science in Society. Retrieved 2008-08-20. 
  49. ^ Vesper, H. W.; Bernert, J. T.; Ospina, M.; Meyers, T.; Ingham, L.; Smith, A.; Myers, G. L. (2007). "Assessment of the Relation between Biomarkers for Smoking and Biomarkers for Acrylamide Exposure in Humans". Cancer Epidemiology Biomarkers & Prevention 16 (11): 2471. doi:10.1158/1055-9965.EPI-06-1058. 

External links[edit]