A weight-of-evidence approach to assess chemicals: case study on the assessment of persistence of 4,6-substituted phenolic benzotriazoles in the environment

Abstract

BackgroundOne important purpose of the European REACH Regulation (EC No. 1907/2006) is to promote the use of alternative methods for assessment of hazards of substances in order to avoid animal testing. Experience with environmental hazard assessment under REACH shows that efficient alternative methods are needed in order to assess chemicals when standard test data are missing. One such assessment method is the weight-of-evidence (WoE) approach. In this study, the WoE approach was used to assess the persistence of certain phenolic benzotriazoles, a group of substances including also such of very high concern (SVHC).ResultsFor phenolic benzotriazoles, assessment of the environmental persistence is challenging as standard information, i.e. simulation tests on biodegradation are not available. Thus, the WoE approach was used: overall information resulting from many sources was considered, and individual uncertainties of each source analysed separately. In a second step, all information was aggregated giving an overall picture of persistence to assess the degradability of the phenolic benzotriazoles under consideration although the reliability of individual sources was incomplete.ConclusionsOverall, the evidence suggesting that phenolic benzotriazoles are very persistent in the environment is unambiguous. This was demonstrated by a WoE approach considering the prerequisites of REACH by combining several limited information sources. The combination enabled a clear overall assessment which can be reliably used for SVHC identification. Finally, it is recommended to include WoE approaches as an important tool in future environmental risk assessments.

Transcriptional and cellular effects of benzotriazole UV stabilizers UV-234 and UV-328 in the freshwater invertebrates Chlamydomonas reinhardtii and Daphnia magna

“…In a field study using the application of 5 different BZT-UVs on agricultural lands, results showed persistence in the soil and slow dissipation rates with half-lives of 179 to 218 d for UV-328 [4]. During the studies realized in the highly contaminated Narragansett Bay, results showed that the concentration range of UV-328 measured in the sediment 12 yr after production had ceased was only 4.6 times lower than the nominal concentration, providing further support to the slow degradation and high persistence of UV-328 [47,48]. In the exposure conditions used in the present study, the BZT-UVs half-lives were estimated by regression analysis at 41.1 AE 10.5 and 43.7 AE 16.8 d for UV-234 and UV-328, respectively.…”

Degradation of Benzotriazole UV Stabilizers in PAA/d-Electron Metal Ions Systems—Removal Kinetics, Products and Mechanism Evaluation

“…On the other hand, the ions were characteristic, only for products made from only one of the benzotriazoles. Based on the ESI-MS spectra and the available literature data [ 79 , 80 , 81 ], the structures of the oxidation products have been proposed ( Figure 8 , Table S11 ). Most of the structural changes occur within the benzotriazole ring, which was discussed in previous works.…”

Moving persistence assessments into the 21st century: A role for weight‐of‐evidence and overall persistence

“…Before the publication of the OECD WoE guiding principles (OECD, 2019 ), many of the key elements outlined by the OECD were already applied in chemical safety assessments (Brandt et al, 2016 ; Bridges & Solomon, 2016 ; Giesy et al, 2014 ; Hughes et al, 2020 ; Wassenaar & Verbruggen, 2021 ). Giesy et al ( 2014 ) used a WoE approach to assess the organophosphorus pesticide chlorpyrifos.…”