Tar bases, coal, lutidine fraction

Endpoint summary

Description of key information

The substance was found to be not readily biodegradable under the conditions of a valid and reliable standard OECD TG 301F biodegradation test.

In available publications, bacterial strains were isolated from different environmental media, including river water, sediments, and soils that were capable of degrading methylated pyridine derivatives under aerobic and anaerobic conditions. The microbial degradation of pyridine derivatives was faster under aerobic conditions with complete degradation generally after less than 28 days (Ettinger et al. 1954). The degradation of pyridine derivatives in soil has also been investigated (Kaiser and Bollag 1992, Sims and Sommers 1985). The studies demonstrated that methylated and dimethylated pyridines were degraded under aerobic conditions generally within less than 32 days. Biodegradation of these compounds in soil was slower and sometimes incomplete under anaerobic conditions. Overall, there is evidence for potential biodegradation of the main constituents of the UVCB substance in surface water and soil, particularly under aerobic conditions. Nevertheless, the available biodegradation study showing no ready biodegradability and the lack of appropriate information on environmental half-lives are suggesting that the substance may be relatively persistent under environmental conditions.