Suchergebnisse

Ready biodegradability tests (RBTs) of the OECD 301 series and the OECD 310 are currently used for testing of ready biodegradability and for the identification of potentially persistent substances. The project aimed giving recommendations for further development and standardization of these tests next to improve knowledge about the application of so called "enhanced" ready tests (eRBT), where a longer test duration up to 60 d and larger vessel volumes are allowed. A survey among European laboratories was performed, to identify their experiences with ready biodegradability testing. The results were discussed among experts on an international workshop in April 2019. Further on, a practical testing programme has been realised with five test compounds in 4 testing series under different conditions. Here, Ibuprofen and 4-Fluorophenol were regarded as being non-persistent while the results for Piperonylbutoxide were inconclusive ("potentially P"). Octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionate did not meet the 60% pass level in any test series and thus also is "potentially P". Cis-13-Docosenonamide (Erucamide) can be considered as being non-persistent based on results from several tests, but some doubts remain, since a high variability between replicates was observed. The testing experience led to suggestions regarding the test design, the evaluation and the interpretation of eRBTs, which could be used as a starting point for further guidance. The impact of the proposed recommendations for the persistence assessment under REACH are discussed.