A critical review of occurrence and emission of brominated flame retardants in indoor consumer products.

Brominated flame retardants (BFRs) are widely used in indoor consumer products to enhance fire safety. Nevertheless, BFRs are gradually emitted into the indoor air and dispersed throughout the environment, making indoor consumer products the predominant source of indoor BFRs and posing potential exposure risk for human. Currently, systematic reviews on their occurrence and emission remain unknown. This study provides the first comprehensive review of both the occurrence and emission of 18 BFR compounds across three product categories: waste electrical and electronic equipment (WEEE)/electrical and electronic equipment (EEE), textiles and upholstery, and non-EEE plastics. Despite restrictions on legacy BFRs (LBFRs), concentrations of LBFRs ranged from ND to 14,000 mg/kg. Among the three categories, textile and upholstery products showed the highest BFR concentrations, with highest concentration up to 275000 mg/kg. Chamber tests on BFRs in consumer products showed temperature and emission duration as major factors influencing emission. The specific emission rate (SER) of BFRs in WEEE/EEE range from 0.2 to 7.1 μg/(h·m) and 0.14-14.5 μg/(h·unit) and 0.0000413-0.00039 μg/(h·g), in textile and upholstery range from 0.000059 to 7.5μg/(h·g), in non-EEE plastic range from 0.0000019 to 0.000418 μg/(h·g) and 0.01-4 μg/(h·m). Emission models based on mass transfer theory have been developed to estimate the SER of semi-volatile organic compounds (SVOCs) from indoor consumer products. However, these models have not yet been applied or validated for predicting the emissions of BFRs. Exposure risk assessments for BFRs based on SER remain limiting, and indoor fate models offer a promising approach to bridge this gap.