Photodegradation of TBBPA/ABS materials and exposure to brominated residues during WEEE recycling

Tetrabromobisphenol-A (TBBPA), the main brominated flame retardant in acrylonitrile-butadiene-styrene (ABS) plastics, is widely found in waste electrical and electronic equipment (WEEE). As an additive, it can migrate from the polymer matrix and degrade, forming hazardous brominated compounds. The photochemical behavior of TBBPA in ABS, however, has not been systematically investigated, limiting accurate evaluation of occupational exposure during recycling. This study examined the photodegradation of TBBPA-containing ABS under controlled UV and thermal conditions using spectroscopic, chromatographic, and microscopic analyses. TBBPA accelerated ABS oxidation through bromine radical reactions, suppressing the induction period typical of commercial ABS. Major transformation products included carboxylic acids, esters, aldehydes, ketones, and lactones. After 220 h of irradiation, about 50 % of TBBPA and 20 % of bromine were lost, accompanied by surface cracking and yellowing that slowed down further oxidation by limiting light and oxygen diffusion. No brominated volatiles were detected in the gas phase, indicating that degradation products remained in solid phase. Bromine-rich residues on the aged polymer surface were easily transferable by contact, suggesting exposure of WEEE workers through dermal, inhalation, or ingestion pathways. These results provide mechanistic evidence of TBBPA degradation in ABS and support improved risk management and safer recycling practices for brominated plastics.