Firemaster 550 (FM550) is a flame retardant (FR) mixture that has become one of the most commonly used FRs in household items such as foam-based furniture and baby products. Because this mixture readily leaches from products, contamination of the environment and human tissues is widespread. Prior work by us and others has reported sex-specific behavioral deficits in rodents and zebrafish following early life exposure. In an effort to understand the mechanisms by which these behavioral effects occur, here we explored the effects of its constituents on behavioral outcomes previously shown to be altered by developmental FM550 exposure. The FM550 commercial mixture is composed of two brominated compounds (BFR) and two organophosphate compounds (OPFRs) at almost equivalent proportions. Both the BFR and the OPFR components are differentially metabolized and structurally distinct, but similar to known neurotoxicants. Here we examined adult Wistar rat offspring socioemotional behaviors following perinatal exposure (oral, to the dam) to vehicle, 2000 μg/day FM550, 1000 μg/day BFR or 1000 μg/day OPFR from gestation day 0 to weaning. Beginning on postnatal day 65 offspring from all groups were subjected to a series of behavioral tasks including open field, elevated plus maze, marble burying, social interaction tests, and running wheel. Effects were exposure-, sex- and task-specific, with BFR exposure resulting in the most consistent behavioral deficits. Overall, exposed females showed more deficits compared to males across all dose groups and tasks. These findings help elucidate how different classes of flame retardants, independently and as a mixture, contribute to sex-specific behavioral effects of exposure.

Firemaster 550 (FM550) 是一种阻燃 (FR) 混合物，已成为泡沫家具和婴儿用品等家居用品中最常用的阻燃剂之一。由于这种混合物很容易从产品中浸出，因此对环境和人体组织的污染很普遍。我们和其他人之前的工作报告了早期暴露后啮齿动物和斑马鱼的性别特异性行为缺陷。为了了解这些行为影响发生的机制，我们在这里探讨了其成分对先前显示会因发育性 FM550 暴露而改变的行为结果的影响。FM550 商用混合物由几乎相等比例的两种溴化化合物 (BFR) 和两种有机磷酸盐化合物 (OPFR) 组成。BFR 和 OPFR 成分的代谢不同且结构不同，但与已知的神经毒物相似。在这里，我们检查了成年 Wistar 大鼠后代从妊娠第 0 天到断奶期间（经口、对母猪）暴露于载体、2000 μg/天 FM550、1000 μg/天 BFR 或 1000 μg/天 OPFR 后的社会情绪行为。从出生后第 65 天开始，所有组的 65 个后代都接受了一系列行为任务，包括旷场、高架十字迷宫、大理石埋葬、社会互动测试和跑轮。影响是暴露、性别和任务特定的，BFR 暴露导致最一致的行为缺陷。总体而言，在所有剂量组和任务中，与男性相比，暴露的女性表现出更多的缺陷。这些发现有助于阐明不同类别的阻燃剂，