biostudies-literatureGobas FAPCEuropean Center for Silicones2065-2072https://www.ebi.ac.uk/biostudies/studies/S-EPMC6852268biostudies-literatureUnknown38(9)We illustrate that the Organisation for Economic Co-operation and Development guideline 305 (OECD-305) for growth-correcting bioconcentration factors (BCFs) and biomagnification factors (BMFs) violates the mass-balance assumption underlying the definition of BCFs and BMFs and provides unrealistic estimates of BCFs and BMFs of chemicals in nongrowing fish. We present and test alternative methods for growth-correcting BCFs and BMFs that maintain mass balance. We conclude that the OECD-305-recommended growth correction of BCFs and BMFs causes error, is unnecessary, and should be revisited. Environ Toxicol Chem 2019;38:2065-2072. © 2019 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC.Environmental toxicology and chemistryGrowth-Correcting the Bioconcentration Factor and Biomagnification Factor in Bioaccumulation Assessments.PMC6852268NALee YSGobas FAPCfalseGrowth-Correcting the Bioconcentration Factor and Biomagnification Factor in Bioaccumulation Assessments.We illustrate that the Organisation for Economic Co-operation and Development guideline 305 (OECD-305) for growth-correcting bioconcentration factors (BCFs) and biomagnification factors (BMFs) violates the mass-balance assumption underlying the definition of BCFs and BMFs and provides unrealistic estimates of BCFs and BMFs of chemicals in nongrowing fish. We present and test alternative methods for growth-correcting BCFs and BMFs that maintain mass balance. We conclude that the OECD-305-recommended growth correction of BCFs and BMFs causes error, is unnecessary, and should be revisited. Environ Toxicol Chem 2019;38:2065-2072. © 2019 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC.2019-01-01T00:00:00Z2019 Sep2025-04-26T01:47:40.815Z2020-05-21T19:20:26ZS-EPMC68522683116271610.1002/etc.4509