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Photodegradation of the „novel“ brominated flame retardant tris-(2,4,6-tribromophenoxy)-s-triazine
(2016)
Brominated flame retardants (BFRs) comprise a class of structurally diverse compounds that are functionally related and used in materials to reduce the flammability of polymers. Due to their global distribution, potential persistence, bioaccumulation and toxicity most of the BFRs of the first Generation are banned or restricted, and replaced by new ones. However, based on similar properties these new compounds may also pose a serious risk by causing adverse effects to human health and the environment.
These alternative BFRs were grouped into two classes: „novel” and „emerging” BFRs. Emerging BFRs are defined as compounds that have been identified in any environmental compartments whereas novel BFRs are only detected in materials and/or goods above 0.1 wt.-%.
The environmental fate of these alternative BFRs is partially unknown. Over the past years a multitude of studies on the photodegradation of BFRs in environmental matrices have been conducted to assess the photochemical behavior and fate in the environment. The photolytic debromination reaction is particularly induced among BFRs by UV exposure.
The novel brominated triazine-based flame retardant tris-(2,4,6-tribromophenoxy)-s-triazine (TTBPTAZ) (Table 1) is a BFR that is mainly used in acrylonitrile butadiene styrene and high impact polystyrene.
Ballesteros-Gómez et al. detected TTBP-TAZ in 8 of 13 plastic parts of consumer products and in 9 of 17 indoor dust samples but the photochemical behavior and fate is not known until now.
The results of the present study, focused on photodegradation processes were performed for the first time for TTBP-TAZ to identify the photolysis intermediates and products to assess the environmental fate.
Phototransformation of the “emerging” BFR 1,3,5-Tris-(2,3-dibromopropyl)-1,3,5-triazine-2,4,6-trione
(2017)
The occurrence and fate of brominated flame retardants (BFRs) in the environment are topics of increasing concern. In recent years, numerous studies about their global transport, UV degradation, bioaccumulation and toxicity were performed to assess their environmental fate. As a result, most of the first generation BFRs are banned or restricted, and replaced by new ones. However, based on similar properties these new compounds may also pose a serious risk by causing adverse effects to human health and the environment. According to the European Food Safety Authority (EFSA) the class of the “emerging” BFRs are defined as compounds that have been identified in any environmental compartments, but the potential for degradation or bioaccumulation of these emerging BFRs is partially unknown.
A representative of this class of compounds is the heterocyclic TDBP-TAZTO which was first detected in mollusks from Chinese bohai sea and in environmental matrices near a manufacturing plant in southern china. Furthermore, Wang et al. describe that the growth of the alga Nannochloropsis sp. is inhibited by TDBP-TAZTO in a concentration dependent manner but the photo-chemical behavior as well as the formation of possible photo-transformation products (PTPs) are still unknown. In order to clarify this complex issue photo-degradation experiments were by determining the rate constants and degradation half-life times of TDBP-TAZTO in different solvent compositions. In this study, the photodegradation of TDBP-TAZTO was performed for the first time to identify its photolysis products and to get a first understanding about the main degradation pathway in environmental matrices.