Last updated on 11 March 2002

1,3-DCP in soy sauce and related products - your questions answered

Background, health aspects, legislation, past surveys, survey of 1,3-DCP in Soy Sauce - 2000 and future work

  • What is 1,3-DCP?

    1,3-DCP (1,3-dichloropropanol) is a derivative of 3-MCPD and has therefore been found to occur in soy sauces and the savoury food ingredient acid-hydrolysed vegetable protein (acid-HVP). 3-MCPD (3-monochloropropane-1,2-diol) is the most common of the chloropropanols and is present at higher levels in soy sauces and acid HVP than 1,3-DCP (see Q4).

  • Why is 1,3-DCP of concern?

    1,3-DCP is a known genotoxic carcinogen in animals. Expert committees in the UK and the European Commission's Scientific Committee for Foods (SCF) have considered toxicological data and advised that it is prudent to consider that 1,3-DCP is genotoxic in-vivo (i.e. does directly damage genetic material).

  • What is the latest advice to industry on 1,3-DCP?

    In May 2001 the UK's Committee on Carcinogenicity of Chemicals in Food, Consumer Products and the Environment (COC) reconsidered data on dichloropropanols, including 1,3-DCP, and advised that "exposure to 1,3 DCP should be reduced to as low a level as technologically feasible."

  • Is 1,3-DCP found in other foods?

    There are no published studies on the occurrence of 1,3-DCP on other foods. The Agency intends to carry out a survey of foods as soon as possible.

  • How can 1,3-DCP be prevented from occurring/be removed from soy sauce

    See Q8

  • Does consuming soy sauce containing 1,3-DCP pose a health risk?

    Consuming soy sauces containing 1,3-DCP may result in a number of health risks including cancer.

  • How much 1,3-DCP can be consumed without causing any harmful health effects?

    The greater the consumption of 1,3-DCP the higher the risk. Since 1,3-DCP is thought to directly damage genetic material it is not possible to establish a safe level of consumption.

  • What action do consumers need to take?

    Consumers should not eat soy sauces identified by this survey as containing 1,3-DCP. Any identified products should be disposed of.

  • Are particular groups of the population more exposed to 1,3-DCP?

    Yes. Those consumers frequently consuming soy sauce containing high levels of 1,3-DCP will be most at risk.

  • Where can I find out more?

    The opinion of the Committee on Carcinogenicity regarding 1,3-DCP can be found on the Department of Health website.

  • What are the adverse effects of 1,3-DCP?

    1,3-DCP causes cancer in animal studies and 1,3-DCP has the potential to react with DNA. Based on the information currently available the COC advice that it is prudent to assume the cancers arise by a genotoxic mechanism.

  • What does genotoxic mean?

    A substance that is harmful to genetic material. Damage to genetic material can lead to cancer or, if it occurs in reproductive cells, be passed on to children.

  • Will 1,3-DCP give me cancer?

    An accurate estimation of the risk of cancer is not possible, but independent experts advise that intakes should be as low as possible.

    It is because exposure to genotoxins has the potential to cause cancer or other irreversible effects that we are issuing the advice not to consume 1,3-DCP containing soy sauces as a precautionary measure.

  • Is there a limit for 1,3-DCP levels in food?

    No. However, the UK will be sending the results of this survey to the European Commission and will request that the setting of an appropriate regulatory limit be discussed by member states as a priority.

  • What other surveys of 1,3-DCP have been carried out?

    Surveys of the savoury ingredient acid hydrolysed vegetable protein (acid-HVP) in which 1,3-DCP was originally identified as a contaminant, were carried out in 1990 and 1993. Of a total of 40 samples analysed in 1990, one contained 1,3-DCP at approximately 0.05mg/kg, which was the limit of quantification at the time. In 1993 a further 34 samples were analysed, none contained 1,3-DCP.

  • What did these show?

    These surveys together with advice from UK based industry, led to the understanding that 1,3-DCP was not a common contaminant of acid hydrolysed vegetable protein (acid-HVP) produced in Europe.

  • What recommendations were given?

    The Food Advisory Committee noted the action of acid-HVP manufacturers to reduce 1,3-DCP levels and urged industry to continue to ensure that low levels are achieved.

  • How many samples had levels of 1,3-DCP?

    17 percent of the samples had 1,3-DCP measured in them.

  • What product contained the highest level of 1,3-DCP?

    A sample of [Jammy Chai] Pure Soy Sauce from China had the highest observed level of 1,3-DCP.

  • What is the most recent advice to industry?

    The COC issued this statement in May 2001 "It is prudent to assume that 1,3-DCP is a genotoxic carcinogen and that exposure to 1,3-DCP should be reduced to as low a level as technologically feasible."

  • What future survey work is to be done on 1,3-DCP in soy sauce?

    See Q28

  • What future survey work is to be done on 1,3-DCP in foods?

    The Agency also intends to commission a survey of 1,3-DCP in selected foods as soon as possible.

  • How much shark, swordfish or marlin should the average consumer eat per week?

    The Agency is advising pregnant women, women who intend to become pregnant, infants and children of all ages to avoid consumption of shark, swordfish and marlin as an interim precautionary measure following a recent FSA survey that revealed relatively high levels of mercury in these species of fish. Occasional consumption of shark, swordfish and marlin as part of a balanced diet by the rest of the population is unlikely to result in harmful effects. However, adults other than those in the groups listed above are advised against eating more than one portion each week of either shark, swordfish or marlin.