Investigation of novel brominated triazine-based flame retardant (TDBP-TAZTO) and its transformation products emitted from fire-retarded textile manufacturing facility and its downstream sewage treatment plant

Abstract

Investigation of transformation products from novel flame retardants emitted throughout their life cycles is crucial for understanding and predicting environmental and human health risks posed by them during the material and product life cycle. Here, to understand more about the emission of TDBP-TAZTO to the environment, we investigated the presence of novel brominated triazine-based flame retardant 1,3,5-tris-(2,3-dibromopropyl)-1,3,5-triazine-2,4,6-trione (TDBP-TAZTO) and its transformation products in the effluent from a facility manufacturing fire-retarded textiles, and in the influent, effluent, and sludge of its closest downstream sewage treatment plant. To acquire mass spectra data of the transformation products in the influent, effluent, and sludge, non-target analysis was carried out by electrospray ionization-quadrupole time-of-flight-high-resolution mass spectrometry with liquid chromatography (LC-ESI-QTOF-HRMS). Then, the HaloSeeker 2.0 software was used to filter the mass spectrometry data for signals attributable to halogenated compounds. Combination of LC-ESI-QTOF-HRMS accurate mass measurements and HaloSeeker screening allowed us to determine the most probable elemental compositions and structures of 11 transformation products from TDBP-TAZTO and to construct a possible transformation pathway that included dehydrobromination, hydroxylation, and decarbonylation reactions. Based on analysis of the absolute intensities, we found that TDBP-TAZTO and its transformation products may not be easily removed by current sewage treatment plant process. There are increasing concerns about environmental contamination by TDBP-TAZTO and its transformation products different from the one which have previously been considered to be c-decaBDE and its lower brominated congeners. However, the present data suggest that concern is also warranted over the presence of TDBP-TAZTO and its transformation products in the environment. The present data will be useful for assessing, predicting, and understanding the environmental contamination and human health risks posed by TDBP-TAZTO, and for considering appropriate measures to control the emission of TDBP-TAZTO and its transformation products during product life cycles.

Keywords: Effluent; HaloSeeker; LC−ESI−QTOF−HRMS; Sludge; TDBP-TAZTO; Transformation product.