Screening of benzothiazoles, benzenediamines, dicyclohexylamine and benzotriazoles 2009
A screening study of benzothiazoles, benzenediamines, dicycyclohexylamine,and benzotriazoles has been carried out in the framework of the Swedish Environmental Protection Agency´s screening program.The overall objective of a screening study is to determine the concentrations of the selected substances in a variety of media in the Swedish environment. Additional aims are to assess the possible emission sources and to highlight important transport pathways in the environment.This screening has been carried out in collaboration with the research program ChEmiTecs “Organic Chemicals Emitted from Technosphere Articles" (www.chemitecs.se, financed by the Swedish Environmental Protection Agency). The aim of ChEmiTecs is to increase the scientific understanding of the magnitude of the problem regarding emissions of organic substances from articles with the objective to support policy development in Sweden and Europe.The benzothiazoles MBT, CBS, DBS and DBD were found in one or more of the sample matrices. The detection frequencies varied both among the substances and the different media. The distribution pattern was most likely affected both by substance properties, i.e. the chemical stability and the tendency of a substance to partition to a certain media, and the use and emission pattern. MBT had the highest detection frequency while the other benzothioazoles were more occasionally found. An important pathway of MBT to the environment is via WWTPs, an indication that the occurrence is due to diffuse emission from e.g. consumer products. The occurrence in storm water indicates traffic related emissions. MBT and the other benzothiazoles did mainly occur in the aquatic environment. Air transport seems to be of minor importance.The benzenediamine DPP was occasionally detected in some of the matrices e.g surface water, storm water and sludge. DCHA was widespread in the environment and it occurred in all sample types except crops. The findings of DCHA in air and deposition indicate that this substance is emitted to air and that atmospheric transport is an important pathway in the environment. The occurrence in storm water as well as in soil indicates that traffic related emissions are important. DCHA was however not found in crops collected in the vicinity to busy roads. Another important pathway for DCHA to the environment is via WWTPs, an indication that the occurrence is due to diffuse emission from e.g. consumer products.There is a widespread occurrence of benzotriazoles in the environment both at background and urban areas. The substances occurred in all the included environmental matrices, air, deposition, surface water, sediment, soil and biota.The results also showed that diffuse spreading through WWTPs, landfills and storm water may be important for the occurrence in the environment. This indicates that these substances are distributed via use of products. UVP is the benzotriazole with the highest usage volume followed by UV 328 and UV327. These substances were also most often found in the highest concentrations. In a brief risk assessment for the aquatic pelagic ecosystems no major risks were identified, i.e. concentrations were generally below the PNEC in surface water and effluents if dilution was considered. DPP did however occur in concentrations above its PNEC in River Viskan and concentrations of DPP and DCHA in the different effluents did at some occasions exceed the PNEC undiluted. No toxicity or ecotoxicity data has been found for any of the benzotriazole substances in the available literature. Any risk estimates have therefore not been carried out.