Fifteen brominated, chlorinated or phosphate ester flame retardants were tested using a battery of 22 different in vitro neurodevelopmental endpoint tests. Only one FR (TCIPP) showed no effect in all tests. The others showed effects in one or several tests, at concentrations of 0.6 – 20 µM. Results were not well predicted by ToxCast. Overall, EHDPHP and BDE-47 were rated as the most hazardous of the tested FRs, and TCEP and BBOEP as least. The authors conclude that real-life risk from these FRs is low (comparing to concentrations in breast milk) but that there is potential concern for risk from combined exposure.
FRs tested: TetraBDE (BDE-47), PentaBDE (BDE-99), Tetrabromobisphenol A (TBBPA), Triphenyl phosphate (TPHP), Tris (2-butoxyethyl) phosphate (TBOEP) and its metabolite Bis-(2-butoxyethyl) phosphate (BBOEP), Isodecyl diphenyl phosphate (IDDPHP), Triphenyl isopropylated phosphate (IPPHP), Tricresyl phosphate (TCP), Tris (1,3-dichloro-isopropyl) phosphate (TDCIPP), tert-butylphenyl diphenyl phosphate (t-BPDPHP), Tri-O-cresyl phosphate (TOCP), 2-ethylhexyl diphenyl phosphate (EHDPHP), Tris (1-chloro-isopropyl) phosphate (TCIPP), Tris (2-chloroethyl) phosphate (TCEP).
“Neurodevelopmental toxicity assessment of flame retardants using a human DNT in vitro testing battery, J. Klose et al., Cell Biol Toxicol 2021https://doi.org/10.1007/s10565-021-09603-2