Application of the margin of exposure (MoE) approach to substances in food that are genotoxic and carcinogenic – Example: 1-Methylcyclopropene and its impurities (1-chloro-2-methylpropene and 3-chloro-2-methylpropene)

The chlorinated impurities of 1-methylcyclopropene possess weak mutagenicity and are carcinogenic in rodent bioassays. Dose-response modelling of the data for 1-chloro-2-methylpropene gave a BMDL10 for nasal carcinomas in male rats of 11mg/kg-bw/day (after correction for the 5 days/week dosage schedule). No human exposure data are available and theoretical estimates had to be used to calculate the MoE. The MoEs ranged from 40,000 to 100,000,000 depending on the assumptions used in the exposure estimation.