BTBPE = 1, 2-bis (2,4, 6-tribromophenoxy) ethane has been used to substitute the now-banned brominated flame retardant Octa-BDE (listed as POP in 2009). Sixty rats were dosed with 0 – 250 gm/kg BTBPE in feed for 30 days. Thyroid hormones FT4 and TT4 were significantly reduced in rats receiving ≥2.5 or 25 mg/kg BTBPE respectively (FT3 and TT3 were not modified). In vitro tests with human thyroid cells (Nthy-or3-1) showed similar results.
“The effects and mechanisms of the new brominated flame retardant BTBPE on thyroid toxicity”, Z. Wang, X. Wei et al., SSRN 2022 http://dx.doi.org/10.2139/ssrn.4102810