Risk assessment of furan exposure in the Norwegian population
Report no: 2012: 30
The Norwegian Scientific Committee for Food Safety (VKM) considers that the current exposure to the potentially carcinogenic substance furan is of health concern in all age groups of Norwegians, particularly among infants and children.
This is the main conclusion in the risk assessment of furan exposure in the Norwegian population, performed by VKM on request of the Norwegian Food Safety Authority.
Furan is a volatile and lipophilic compound formed in a variety of heat-treated commercial foods and contributes to the sensory properties of the product.
High furan concentrations have been found in coffee. Furan is also found in canned and jarred foods, including baby food containing meat and various vegetables.
The occurrence of furan in a variety of foods suggests that there are multiple routes of furan formation rather than a single mechanism. There is limited knowledge whether home-made food may contain as much furan as commercial foods.
Carcinogenic in animals
The liver is the main target organ for furan toxicity both in mice and rats, but the rat is the most sensitive species. A dose-dependent increase in hepatocellular adenomas and carcinomas was observed in mice and rats, and an increase in the incidence of cholangiocarcinomas was observed in rat liver.
On the basis of the available data, rat cholangiocarcinomas, the most sensitive end point in rodents, may be relevant for assessing human risk from furan.
Available in vivo data with furan indicate that it forms a reactive metabolite which can react with DNA and induce mutations. VKM considers that a genotoxic mechanism in furan-induced carcinogenesis cannot be excluded and has assessed furan as a genotoxic carcinogen.
Sources and human intake
The calculated furan exposures from food and beverages are based on the most recent national food consumption surveys for infants, small children, adolescents and adults (Spedkost, Småbarnskost, Ungkost and Norkost). When national data were lacking, VKM has used occurrence data of furan from other countries.
The consumption for each relevant food or food category in the dietary surveys were multiplied with the corresponding mean furan concentrations and totalled for each individual.
For 6-, 12- and 24-month-old children, the main source of furan exposure is jarred baby food. The major furan source for 4-, 9- and 13-year old children is breakfast cereals, whereas for adults it is coffee. The highest furan exposure was calculated for 12-month-old infants, ranging from 0.62-1.51 µg/kg bw/day. In adults the furan exposure ranged from 0.27-0.82 µg/kg bw/day.
Margin of exposure
VKM used the Margin of Exposure (MOE) approach and the benchmark dose (BMD) methods in this risk assessment. Based on the 9-month interim evaluation of a 2-year rat study from the National Toxicology Program (NTP, 1993) and inclusion of a correction factor of 7 to account for shorter than full life-time study duration, a point of departure (POD) of 0.02 mg/kg bw/day was chosen.
For mean furan exposure among infants, children and adolescents, the MOE-values ranged from 29 in 12-month-infants to 2000 in 13-year-old adolescents. Among high consumers in these groups, the MOE-values ranged from 13 to 400. In adults, the MOE-values ranged from 59 to 74 for mean furan exposure and from 24 to 26 for high exposure.
Uncertainties and limitations
VKM says it should be noted that the risk assessment of furan contains notable uncertainties and limitations. The use of the 9-month interim study in rats including a correction factor of 7 to derive a POD, instead of the full life-time study, is likely to overestimates the hazard of furan.
A possible over-diagnosis of the cholangiocarcinomas due to the similarities in histopathology between cholangiofibrosis and cholangiocarcinomas in rats, may also overestimate the hazard. Additionally, there are limitations in assessing food consumption and furan content in foods, leading to uncertainties in estimation of furan exposure.
VKM considers that the current exposure to furan in all age groups, particularly among infants and children, is of health concern.
The assessment has been performed by the VKM Panel on Food Additives, Flavourings, Processing Aids, Materials in Contact with Food and Cosmetics, and the VKM Panel on Contaminants.