Dibutylbis(dodecylthio)stannane

Biodegradation in water: screening tests

Description of key information

In a Ready Biodegradability: Manometric Respirometry Test (OECD Guideline 301 F) the test material was considered to be not readily biodegradable. The percentage degradation of dibutyloxostannane after 28 days of incubation did not exceed 0% in a manometric respiration test at a mean test substance concentrations of 34±3.9 mg/l calculated from the ThOD NH3 (1.54 mg O2/mg) of test substance. The biodegradation of dibutyloxostannane did not exceed the pass level of 60% ThOD NH3 within 28 days and, therefore, is classified as not readily biodegradeable. Dibutyloxostannane is not toxic to the inoculum, but a slight inhibition of the degradation of the reference substance was observed.
As no biodegradation data are available for dibutylbis(dodecylthio)stannane this endpoint has been addressed by using a read across approach from dibutyltin dioxide. 

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Additional information

It is known through industry and use that all dibutyltin compounds degrade into dibutyltin and the appropriate ligand, and so on this basis, it is possible to read-across between the different dibutyltin compounds to address the biodegradation in water: screening tests endpoint. As no biodegradation data are available for dibutylbis(dodecylthio)stannane this endpoint has been addressed by using a read across approach from dibutyltin dioxide.

Reference: Hanstveit R (2003) - Read-across from DBTO.

Reliability score and rationale: 2 (reliable with restrictions). Study conducted in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not affect the quality of the relevant results, however the study is being used for read-across purposes from a supporting substance.