Assessment of cancer risk from ethylene oxide residues in spices imported into New Zealand

Quantitative estimates of cancer risks from ethylene oxide (ETO) residues w ere constructed based on 200 retail samples of various spices in New Zealan d. Two samples of cinnamon contained detectable ETO. The highest value enco untered was 15 ppm. ETO was not detected in the remaining 198 samples. Howe ver, 31 samples had detectable levels of ethylene chlorohydrin (ECH) and/or ethylene bromohydrin (EBH). A conservative estimate of ETO intake, based o n average spice consumption, was 3.4 x 10(-6) mg/kg/day. Cancer potency fac tors for ETO ranging from 0.29 to 0.55 (mg/kg/day)(-1) were used to form ca ncer risk estimates. The resulting estimates of average lifetime excess can cer risk was 0.8 x 10(-6) to 1.7 x 10(-6). The US 97.5 percentile value for spice consumption (2.8 kg spices per year), gave an extreme upper-end esti mate of lifetime cancer risk of approximately 1.4 x 10(-5). These risks are practically negligible considering the conservative assumptions used :in e stimating exposure to ETO. The exposures to ECH and EBH are 200-300-fold hi gher than to ETO. These compounds are of lesser potency to ETO in terms of mutagenicity or carcinogenicity in studies to date. However, the precise co ntribution of these compounds to the cancer risk estimate is uncertain due to large toxicological data gaps, including the absence of a 2-year cancer bioassay by the oral route. (C) 2001 Elsevier Science Ltd. All rights reser ved.