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3-MCPD
IUPAC name	3-chloropropane-1,2-diol
Other names	α-Chlorohydrin, glycerol α-monochlorohydrin, chlorodeoxyglycerol
Identifiers
CAS number	96-24-2 Y
PubChem	7290
EC number	202-492-4
ChEBI	18721
SMILES	ClCC(O)CO
InChI	1/C3H7ClO2/c4-1-3(6)2-5/h3,5-6H,1-2H2
InChI key	SSZWWUDQMAHNAQ-UHFFFAOYAR
ChemSpider ID	7018
Properties
Molecular formula	C3H7ClO2
Molar mass	110.539 g·mol−1
Appearance	Viscous, colorless liquid
Density	1.32 g·cm−3
Melting point	−40 °C, 233 K, -40 °F
Boiling point	213 °C, 486 K, 415 °F
Hazards
MSDS	External MSDS
R-phrases	R26/27/28, R36/37/38
S-phrases	S24, S45
Y (what is this?)  (verify) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

3-MCPD or (3-monochloropropane-1,2-diol or 3-chloro-1,2-propanediol) is an organic chemical compound which is carcinogenic and highly suspected to be genotoxic in humans, has male anti-fertility effects, and is a chemical byproduct which may be formed in foods, the most commonly found member of chemical contaminants known as chloropropanols.

It is primarily created in foods by protein hydrolysis by adding hydrochloric acid to speed up the reaction of the (soy) protein with lipids at high temperatures. Another method 3-MCPD can also occur in foods which have been in contact with materials containing epichlorohydrin-based wet-strength resins - used in the production of some tea bags and sausage casings.^[1]

It has been found far exceeding health standards by in some cases thousand of times in many Chinese and Southeast Asian sauces such as Oyster sauce, Hoisin sauce and Soy sauce, but Korean or Japanese sauces do not utilize hydrochloric acid in production and therefore do not produce chloropropanols. Using hydrochloric acid is a far cheaper and faster method but inevitably creates carcinogens, which is why artificial soy sauce can sell for far cheaper than traditionally fermented soy sauce. The manufacturing process for acid-hydrolyzed protein can be modified to reduce the levels of 3-MCPD that are formed, but cannot completely eliminate them.

Absorption and toxicity

3-MCPD is considered to be carcinogenic to rodents via a non-genotoxic mechanism^[2]. It is able to cross the blood-testis barrier and blood-brain barrier. (Edwards et al. 1975). The oral LD50 of 3-chloro-1,2-propanediol was reported to be 152 mg/kg bodyweight in rats (Ericsson & Baker, 1970).

3-MCPD also has male antifertility effects ^[3][4] and can be used as a rat chemosterilant^[5].

Legal limits

The joint Australia New Zealand Food Authority (ANZFA) set a limit for 3-MCPD in soy sauce of 0.02 milligrams per kilogram, in line with European Commission standards which came into force in the EU in April 2002.

Incidents

A survey of soy sauces and similar products available in the UK was carried out by the Joint Ministry of Agriculture, Fisheries and Food/Department of Health Food Safety and Standards Group (JFSSG) in 2000 and reported more than half of the samples collected from retail outlets contained various levels of 3-MCPD ^[6].

• In 2001 the United Kingdom Food Standards Agency found in tests of various oyster sauces and soy sauces that some 22% of samples contained a chemical called 3-MCPD (3-monochloropropane-1,2-diol) at levels considerably higher than those deemed safe by the European Union. About two-thirds of these samples also contained a second chloropropanol called 1,3-DCP (1,3-dichloropropane-2-ol) which experts advise should not be present at any levels in food. Both chemicals have the potential to cause cancer and the Agency recommended that the affected products be withdrawn from shelves and avoided.^[7][8]

• Britain's Food Standards Agency (FSA) singled out brands and products imported from Thailand, China, Hong Kong and Taiwan. Brands named in the British warning include Golden Mountain, King Imperial, Pearl River Bridge, Jammy Chai, Lee Kum Kee (李錦記), Golden Mark, Kimlan (金蘭）, Golden Swan, Sinsin, Tung Chun and Wanjasham soy sauce. Knorr soy sauce was also implicated, as well as Uni-President Enterprises Corporation (統一企業公司) creamy soy sauce from Taiwan, Silver Swan soy sauce from the Philippines, Ta Tun soy bean sauce from Taiwan, Tau Vi Yeu seasoning sauce and Soya bean sauce from Vietnam, Zu Miao Fo Shan soy superior sauce and Mushroom soy sauce from China and Golden Mountain and Lee Kum Kee chicken marinade.^{[9 ]}

• Relatively high levels of 3-MCPD and other chloropropanols were found in soy sauce and other foods in China between 2002 and 2004^[10].

• In 2006, Certain batches of Marca Pina Soy Sauce (1 litre) have been found to be contaminated with levels of (3-MCPD) above EU statutory limits. According to the label, the affected brand of Soy sauce was manufactured in the Philippines by Pinakamasarap Corporation.

• In 2007 in Vietnam, 3-MCPD was found in toxic levels (Testing since 2001, In 2004, the HCM City Institute of Hygiene and Public Health found 33 of 41 sample of soya sauce with high rates of 3-MCPD, including six samples with up to 11,000 to 18,000 times more 3-MPCD than permitted, an increase over 23 to 5,644 times in 2001) ^[11] in soy sauces there in 2007, along with formaldehyde in the national dish Pho, and banned pesticides in vegetables and fruits. A prominent newspaper Thanh Nien Daily commented, "Health agencies have known that Vietnamese soy sauce, the country's second most popular sauce after fish sauce, has been chock full of cancer agents since at least 2001," ^[12]

• In March 2008 in Australia, "carcinogens" were found in soy sauces there, and were advised to avoid soy sauce. ^[13]

• In Nov 2008, Britain's Food Standards Agency reported a wide range of household name food products from sliced bread to crackers, beefburgers and cheese with 3-MCPD above safe limits. Relatively high levels of the chemical were found in popular brands such as Mother's Pride, Jacobs crackers, John West, Kraft Dairylea and McVitie's Krackawheat. The same study also found relatively high levels in a range of supermarket own-brands, including Tesco char-grilled beefburgers, Sainsbury's Hot 'n Spicy Chicken Drumsticks and digestive biscuits from Asda. The highest levels of 3-MCPD found in a non- soy sauce product, crackers, was 134 mcg per kg. The highest level of 3-MCPD found in soy sauce was 93,000 mcg per kg, 700 times higher. The legal limit for 3-MCPD coming in next year will be 20 mcg per kg. But the safety guideline on daily intake is 120mcg for a 60 kg person per day.^[14]

Current status

These companies continue to use the rapid soy protein hydrolyzation method, but modify methods to lower contaminants to meet standards. Hydrolyzing always produces some 3-MCPD, but for the 1,3-DCP, a byproduct of 3-MCPD,　there is no standard to meet as it is unregulated, scientists said that cancer found in reproductive cells caused by 1,3-DCP can cause cancer and genetic damage that can be passed to generations of offspring who have never been exposed to the chemical.^{[9 ]}

See also

• Food contamination

External links

• US FDA Compliance Policy on 3-MCPD in Asian Sauces
• Chloropropanols (WHO Food Additive Series 32)
• 3-MCPD detection and testing

References

1. ^ IFST issues statement on 3-MCPD
2. ^ Robjohns S, Marshall R, Fellows M, Kowalczyk G (September 2003). "In vivo genotoxicity studies with 3-monochloropropan-1,2-diol". Mutagenesis 18 (5): 401–4. PMID 12960406. http://mutage.oxfordjournals.org/cgi/pmidlookup?view=long&pmid=12960406.  
3. ^ Ericsson RJ, Baker VF (March 1970). "Male antifertility compounds: biological properties of U-5897 and U-l5,646". Journal of reproduction and fertility 21 (2): 267–73. PMID 5443210.  
4. ^ Samojlik E, Chang MC (April 1970). "Antifertility activity of 3-chloro-1, 2-propanediol (U-5897) on male rats". Biology of reproduction 2 (2): 299–304. PMID 5520328. http://www.biolreprod.org/cgi/pmidlookup?view=long&pmid=5520328.  
5. ^ Ericsson RJ (July 1970). "Male antifertility compounds: U-5897 as a rat chemosterilant". Journal of reproduction and fertility 22 (2): 213–22. PMID 5428943.  
6. ^ Macarthur R, Crews C, Davies A, Brereton P, Hough P, Harvey D (November 2000). "3-monochloropropane-1,2-diol (3-MCPD) in soy sauces and similar products available from retail outlets in the UK". Food additives and contaminants 17 (11): 903–6. PMID 11271703.  
7. ^ Food.gov.uk press release soysauce
8. ^ Chart with five mentions of affected oyster sauces
9. ^ ^{a b} barchronicle(Philippine government)
10. ^ Fu WS, Zhao Y, Zhang G, et al. (August 2007). "Occurrence of chloropropanols in soy sauce and other foods in China between 2002 and 2004". Food additives and contaminants 24 (8): 812–9. doi:10.1080/02652030701246039. PMID 17613068. http://www.informaworld.com/openurl?genre=article&doi=10.1080/02652030701246039&magic=pubmed.  
11. ^ Soya sauce stirs worry and discontentment among public
12. ^ Toxic soy sauce, chemical veggies -- food scares hit Vietnam
13. ^ 'Cancer chemical' in soy sauce
14. ^ The cancer chemical lurking in our food