Statistical post-processing method for evaluating bioaccumulation in fish due to dietary exposure in Japan

Abstract

Abstract In 2018, the dietary exposure bioaccumulation fish test of the Organization for Economic Co-operation and Development Test Guideline No. 305 was introduced into Japan’s Chemical Substances Control Law. The Japanese government has adopted a single definitive testing criterion for the absence of bioaccumulation: the growth-corrected kinetic dietary magnification factor (BMFkg) must be less than 0.007. We used statistical post-processing to assess the possibility of expanding the criteria for not being highly bioaccumulative. Based on our results, we proposed the criterion that the test substance should be considered not highly bioaccumulative if the following two conditions are met: (1) The ratio of the maximum to the minimum measured 5% lipid-normalized biomagnification factor (BMFL, n = 5) for the test substance and reference substance should be less than 3.0; (2) For the measured BMFL of the test substance (n = 5), the probability that the next (the sixth) BMFL is below 0.0334 should exceed 95% based on statistical post-processing. Application of our suggested criteria to Japan’s Chemical Substances Control Law implies that the BMFL for chemicals that are not highly bioaccumulative in the dietary exposure bioaccumulation fish test would be increased from 0.007 to 0.0149.