Following the ban of many historically-used flame retardants (FRs), numerous replacement chemicals have been produced and used in products, with some being identified as environmental contaminants. One of these replacement flame retardants is 1,2-dibromo-4-(1,2-dibromoethyl)-cyclohexane (DBE-DBCH; formerly abbreviated as TBECH), which to date has not been identified for risk assessment and potential regulation. DBE-DBCH technical mixtures consist largely of α- and β-diastereomers with trace amounts of γ- and δ-DBE-DBCH. The α- and β-isomers are known contaminants in various environmental media. While current global use and production volumes of DBE-DBCH are unknown, recent studies identified that DBE-DBCH concentrations were among the highest of the measured bromine-based FRs in indoor and urban air in Europe. Yet our mass balance fugacity model and modeling of the physical-chemical properties of DBE-DBCH estimated only 1% partitioning to air with a half-life of 2.2 d atmospherically. In contrast, our modeling characterized DBE-DBCH adsorbing strongly to suspended particulates in the water column (~12%), settling onto sediment (2.5%) with minimal volatilization, but with most partitioning and adsorbing strongly to soil (~85%) with negligible volatilization and slow biodegradation. Our modeling further predicted that organisms would be exposed to DBE-DBCH through partitioning from the dissolved aquatic phase, soil, and by diet, and given its estimated logKow (5.24) and a half-life of 1.7 d in fish, DBE-DBCH is expected to bioaccumulate into lipophilic tissues. Low concentrations of DBE-DBCH are commonly measured in biota and humans, possibly because evidence suggests rapid metabolism. Yet toxicological effects are evident at low exposure concentrations: DBE-DBCH is a proven endocrine disruptor of sex and thyroid hormone pathways, with in vivo toxic effects on reproductive, metabolic, and other endpoints. The objectives of this review are to identify the current state of knowledge concerning DBE-DBCH through an evaluation of its persistence, potential for bioaccumulation, and characterization of its toxicity, while identifying areas for future research.

在禁止使用许多历史悠久的阻燃剂（FRs）之后，已经生产了许多替代化学品并用于产品中，其中一些被鉴定为环境污染物。这些替代阻燃剂中的一种是1,2-二溴-4-（1,2-二溴乙基）-环己烷（DBE-DBCH；以前缩写为TBECH），迄今为止尚未确定其可用于风险评估和潜在监管。DBE-DBCH技术混合物主要由α-和β-非对映异构体以及痕量的γ-和δ-DBE-DBCH组成。α-和β-异构体是各种环境介质中的已知污染物。尽管目前尚不清楚DBE-DBCH的全球使用量和生产量，但最近的研究表明，DBE-DBCH的浓度是欧洲室内和城市空气中测得的溴基FR的最高值之​​一。然而，我们的质量平衡逸度模型和DBE-DBCH的物理化学性质模型估计仅分配给空气的比例为1％，在大气中的半衰期为2.2 d。相比之下，我们的模型的特征是DBE-DBCH强烈吸附水柱中的悬浮颗粒（〜12％），沉降到沉积物（2.5％）上，挥发最少，但大部分分配和吸附强烈吸附到土壤（〜85％）上。挥发性可忽略不计，生物降解速度缓慢。我们的模型进一步预测，通过从溶解的水相，土壤和饮食中分配，生物将暴露于DBE-DBCH中，并给出其估计的对数 我们的模型的特征是DBE-DBCH对水柱中的悬浮颗粒物（〜12％）的吸附能力强，在挥发物最少的情况下沉降到沉积物（2.5％）上，但在大部分分散作用下，对土壤的吸附力强（〜85％），而对挥发的影响可忽略不计。缓慢的生物降解。我们的模型进一步预测，通过从溶解的水相，土壤和饮食中分配，生物将暴露于DBE-DBCH中，并给出其估计的对数 我们的模型的特征是DBE-DBCH对水柱中的悬浮颗粒物（〜12％）的吸附能力强，在挥发物最少的情况下沉降到沉积物（2.5％）上，但在大部分分散作用下，对土壤的吸附力强（〜85％），而对挥发的影响可忽略不计。缓慢的生物降解。我们的模型进一步预测，通过从溶解的水相，土壤和饮食中分配，生物将暴露于DBE-DBCH中，并给出其估计的对数ķ流（5.24）和鱼1.7 d的半衰期，DBE-DBCH预计在生物体内积累到亲脂性组织。通常在生物区系和人类中测量到低浓度的DBE-DBCH，这可能是因为证据表明新陈代谢迅速。然而，在低暴露浓度下，其毒理作用是显而易见的：DBE-DBCH是一种经证实的内分泌干扰物，可破坏性和甲状腺激素途径，并对生殖，代谢和其他终点具有体内毒性作用。这次审查的目的是通过评估其持久性，生物蓄积潜力及其毒性特征，从而确定有关DBE-DBCH的当前知识状态，同时确定未来的研究领域。