Furan is a colourless, volatile organic compound that is used in some chemical manufacturing industries and may also be found in low levels in some heat-treated foods, such as canned or jarred foods. Furan in foods can form through multiple pathways that involve different naturally-present starting compounds that undergo thermal degradation or chemical rearrangement during food processing. The presence of furan in food is a potential concern because of indications of liver toxicity, including carcinogenicity, in experimental animals that were exposed to furan through the diet over their lifetime. The International Agency for Research on Cancer (IARC) has classified furan as possibly carcinogenic for humans.
The chemical "furan" is different from "furans". "Furans" is an abbreviation of chlorinated dibenzofurans and are chemically related to a group of chemicals called dioxins. Dioxins and furans are environmental contaminants, not processing-induced food contaminants, and have distinctly different chemical structures and toxicities compared to furan.
In May 2004 the United States Food and Drug Administration (US FDA) identified low levels of furan in a wider variety of foods than previously reported, most notably in foods that undergo thermal treatment such as canning or jarring. This discovery resulted from the development of a new analytical method that can detect very low concentrations of furan and be applied to a wide variety of foods. In response to the FDA's discovery, Health Canada and other international jurisdictions began researching how furan forms and what levels are present in foods, as well as the hazard that furan may pose to human health.
Health Canada's scientists have identified several formation pathways of furan in processed foods; these involve the oxidation of polyunsaturated fatty acids and similar compounds and the decomposition of ascorbic acid derivatives. Furan can also be formed from various carbohydrate precursors. Further investigation may lead to the identification of other possible mechanisms of formation. Fully understanding how furan is formed in foods will be useful in developing ways to potentially control its formation.
The Food Directorate of Health Canada has analyzed more than 200 samples of foods, including over 25 samples of baby food, that are found on the Canadian market for furan and some of its derivatives (2-methylfuran and 3-methylfuran). The most up-to-date analytical methods, which Health Canada developed, were employed.
Health Canada used these data to estimate dietary exposure to furan in the Canadian population. Estimated mean exposures to furan in children (1 to 3 years of age) and adults (≥ 18 years of age) are 0.32 and 0.18 micrograms per kilogram of body weight per day (µg/kg bw per day), respectively. Dietary exposures to total furan (furan plus 2- and 3-methylfuran) in children and adults are 0.40 and 0.20 µg/kg bw per day, respectively. Young children typically eat more food per unit of body weight relative to older age groups and are therefore exposed to greater amounts of contaminants on a body weight basis. Of the foods included in the exposure assessment, those contributing most to Canadian exposure are: coffee (adults); meat-containing soups, stews and chili con carne (adults and children); and canned pasta (adults and children). Health Canada's exposure estimates are similar to those for populations in other parts of the world such as the United States and Europe.
Although there is evidence that furan levels can be reduced in some foods through volatilization (vaporization) during cooking (e.g., warming and stirring canned or jarred foods in an open saucepan), there is currently a lack of quantitative data for all foods. No information is available on other potential methods of mitigating dietary exposure to furan.
Health Canada experts participate in meetings of the Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives (JECFA), at which toxicological and dietary exposure evaluations of compounds such as furan are conducted. Based on the estimated dietary exposure to furan and the results from studies in experimental animals, the February 2010 JECFA meeting concluded that furan is a health concern and identified furan as a priority for further research. Health Canada also conducts toxicological studies in laboratory animals in order to better understand the potential human health risks posed by the low levels of furan and its derivatives that humans are exposed to through the diet. While some effects related to liver toxicity in experimental animals have been observed at relatively low doses, current dietary exposure estimations are considerably lower than even these levels.
Health Canada regularly reviews new toxicological research on furan that is conducted internationally. In contrast to previous evidence that suggested furan is a potential non-threshold carcinogen, recent studies examining how furan causes tumour formation and carcinogenicity in experimental animals indicate that there may be a threshold level of exposure below which there would be no carcinogenic risk. Ongoing research by Health Canada scientists will further attempt to define the nature of the dose-response relationship with respect to toxic effects in experimental animals and the relevance to human health.
Health Canada is of the opinion that furan may represent a health concern and that there is a need for further research before the risk posed by furan in foods can be fully understood.
Health Canada will continue to keep Canadians informed about any developments relating to furan in foods.
Until further information becomes available on the potential for effects of furan on human health, Health Canada is not recommending that Canadians change their dietary habits due to the presence of furan in some foods. Health Canada continues to recommend that Canadians consume a variety of foods from each food group as outlined in Eating Well with Canada's Food Guide.
To obtain an electronic copy of the March 2016 - Update on the Assessment of Exposure to Furan from the Canadian Retail Food Supply, please send an e-mail to firstname.lastname@example.org with the subject heading "HPFB BCS Furan EA 2016-eng"