Refined hazard characterization of 3-MCPD using benchmark dose modeling

3-Monochloropropane-1,2-diol (3-MCPD)-esters represent a newly identified class of food-borne process contaminants of possible health concern. Due to hydrolysis 3-MCPD esters constitute a potentially significant source of free 3-MCPD exposure and their preliminary risk assessment was based on toxicological data on free 3-MCPD. 3-MCPD is a non-genotoxic carcinogen and a (provisional maximum) tolerable daily intake ((PM)TDI) of 2 mu g/kg bodyweight per day was established by the Scientific Committee on Food and the Joint FAO/WHO Expert Committee on Food Additives. Both committees derived the TDI from a lowest observed adverse effect level, not a no observed adverse effect level, for renal tubular hyperplasia, using an uncertainty factor of 500. When using the Benchmark Dose (BMD) approach and a BMDL10 value as point of departure, part of this uncertainty factor of 500 would no longer be needed. The present study presents a BMD analysis of the currently available chronic data on 3-MCPD mediated induction of tubular hyperplasia in rats as the most sensitive endpoint. The results indicate a (model-averaged) BMDL10 value of 0.72 mg/kg bw/day. The TDI that would be derived based on this BMDL10 value will depend on the uncertainty factor chosen. Using the default uncertainty factor of 100 for inter- and intraspecies extrapolation would result in a TDI of 7 mu g/kg bw/day.