Abstract Due to international restrictions placed on certain organic flame retardants (OFRs), efforts to find safe and effective alternatives are required. In the present study, a total of 13 structurally diverse OFRs, associated with different chemical groupings defined by Environment and Climate Change Canada risk assessors, were screened using an in vitro, chicken hepatic cell culture approach. Cell viability was determined following exposure to a wide concentration range (0.01–300 µM) of the 13 OFRs to provide an initial ranking of relative potency and to select concentrations for gene expression evaluation. Screening assessment groupings that had the lowest LC50 values included alkyl or aryl organophosphate esters and TBBPA and two derivatives (range of 2.8–19.3 µM). Of the 43 target genes on a Chicken ToxChip PCR array, 5/13 OFRs dysregulated ≥ 21 genes and were predominantly from phosphorous-based groupings including aryl organophosphate esters, phosphite/ate/onate/oro-chlorothioates, and phosphonium salts. Several of the OFRs had limited existing ToxCast data and thus, this study provides novel effects data for potential OFR replacement alternatives and identifies certain chemical groupings that may be candidates for follow up whole animal evaluation using avian embryos.
Crump et al. (Sat,) studied this question.