efsa-opinion-chromium-food-drinking-water

Chromium in food and drinking water
Food preparation using stainless steel containers, processors and utensils may add Cr(III) to the
presence of chromium in food. As data on food as consumed are practically not present in the dataset
applied, this could have led to a potential underestimation of the exposure to Cr(III) in food.
A large proportion of samples with left-censored data introduced considerable uncertainties to the
overall dietary exposure estimate, particularly for drinking water. Therefore the LB values reported in
this opinion tend to underestimate, while UB tends to overestimate the dietary exposure.
The limited data on both consumption and occurrence data on human milk led to use a simulated
scenario to estimate the exposure to Cr(III) in infants exclusively fed with human milk. This adds
uncertainty to the estimated contribution of human milk to the exposure to Cr(III). There is uncertainty
associated to the dietary exposure calculated for the vegetarian population since very limited
consumption data are available.
The lack of appropriate consumption data on fortified foods, foodstuffs for particular nutritional use
(PARNUTS) and food supplements obliged to the use of a simulated scenario that adds uncertainty to
the contribution of these products to the exposure to Cr(III).
There are also insufficient data on consumption for children younger than one year (infants), which
adds uncertainty to the exposure calculations in this age group.
Overall, there is considerable uncertainty regarding the total dietary exposure to chromium from food
and water intended for human consumption and mineral waters.
9.3. Model input (parameters)
Standardized methods exist for the determination of total chromium in food and in water. For Cr(VI)
in water, standardised methods exist, however, no validated or standardised method for speciation of
chromium in food is available. Limited standard or certified reference materials are available for
chromium species. Regular proficiency testing is organised for total chromium in foodstuffs and
water, and only proficiency testing for Cr(VI) in water exists. The analytical results used for exposure
assessment were performed by different laboratories at largely varying LOQ/LODs. Those limitations
may have added to the overall uncertainty of the analytical results.
9.4. Other uncertainties
Toxicity of trivalent chromium
The CONTAM Panel considered it appropriate to establish a TDI Cr(III) based on the NOAEL of a
2-year NTP study in rats (NTP, 2010) where no adverse effects were observed even at the highest dose
tested. Due to the uncertainty in the available data on developmental and reproduction toxicity, the
CONTAM applied an uncertainty factor of 10 in addition to the default uncertainty factor of 100 for
the extrapolations from rodents to humans and for human variability.
Toxicity of hexavalent chromium
Cr (VI) has been classified by IARC as being carcinogenic to humans (group 1) and was identified by
the CONTAM Panel as genotoxic and carcinogenic. An MOE approach was applied, based on the
combined incidence of adenomas and carcinomas in the small intestine from a 2-year study in mice
(NTP, 2008). The CONTAM Panel noted that the BMDL 10 and resulting MOEs would be 3.8 times
higher if based on carcinoma incidence only.
Observations in humans showed toxicity of chromium at very high doses resulting after accidental and
intended intoxications. Epidemiological data on dietary exposure were negative or inconclusive.
Given that the CONTAM Panel used the rodent tumour data and the MOE approach for the risk
assessment of Cr(VI), uncertainty exists on whether the MOE of 10 000 adequately accounts for
possible differences in the level of reduction of Cr(VI) in GI tract in humans as compared to rodents.
Uncertainty exists on the impact of the competing processes of reduction and absorption of ingested
EFSA Journal 2014;12(3):3595 119