Per- and Poly-fluoroalkyl Substances (PFAS) (Chemicals and Contaminants).

Abstract

Food Safety Commission of Japan (FSCJ) conducted a self-tasking risk assessment of per- and poly-fluoroalkyl substances (PFAS) in food. Scientific findings and risk evaluation data regarding PFAS, of international organizations, government agencies in other countries, etc., were reviewed in the current risk assessment. The scientific literature related to three major compounds of PFAS, perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA) and perfluorohexane sulfonate (PFHxS), was surveyed and served for the discussion. Reference doses were derived from two animal experiments* described below. To determine the reference dose, dose estimation models developed by overseas evaluation institutions were adopted for conversion of POD (point of departure) in animal experiments to POD_HED (Human Equivalent Dose). Based on the discussions and estimation, the tolerable daily intake (TDI) was appropriately set as 20 ng/kg body weight/day (2×10^-5 mg/kg body weight/day) for PFOS and as 20 ng/kg body weight/day (2×10^-5 mg/kg body weight/day) for PFOA. Insufficient scientific findings precluded the evaluation to specify a reference dose of PFHxS. The average daily intake in Japan was obtained from the Total Diet Study conducted in a limited number of regions during the fiscal years 2012-2014: PFOS (Lower Bound to Upper Bound (LB-UB)** 0.60-1.1 ng/kg body weight/day, and PFOA (LB-UB) 0.066-0.75 ng/kg body weight/day. These values were lower than the TDIs. Due to the lack of sufficient data on PFAS concentrations and their distribution in various foods, it is necessary to be aware of these intake estimates carrying considerable uncertainty.