Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

Biodegradation in water: screening tests

Regarding biodegradation in water (screening tests) three different experimental as well as two QSAR results are available for the test substance.

The first key study reports about the readily biodegradation potential according to OECD guideline 301B (Mead, 2001). The test material attained 36 % degradation after 28 days and therefore cannot be considered to be "readily biodegradable" under the strict terms and conditions of OECD guideline 301B. As supporting information, an experiment was conducted according to OECD guideline 301F, since also in this study, the test substance was found to be not readily biodegradable (Richter, 2011). Further supporting information is given by a prediction with the computer program BIOWIN v4.10 (EPIWIN software) by US-EPA as well as with the Start plug-in in Toxtree (Chemservice S.A., 2011). The overall prediction result is that the test substance is not readily biodegradable. Also under anaerobic conditions the substance is not expected to be degraded fast. Toxtree categorizes the chemical into class II - persistent.

The potential of inherent biodegradation of the test substance was tested in the second key study. OECD 302 C (Inherent Biodegradability: Modified MITI Test (II)) served as test guideline and a mixed population of aquatic microorganisms (activated sludge) collected from two different aeration tanks was used as inoculum (Richter, 2011). The test material attained 56 % degradation after 28 days and therefore is considered to be “not inherently biodegradable”. In principle, biodegradation will probably take place.

All available data confirm that the test substance is neither readily nor inherently biodegradable, however, according to the German Umweltbundesamt (UBA), it can be considered a “Partially Biodegradable” substance.

Biodegradation in water and sediment: simulation tests and biodegradation in soil

Neither exposure to water and sediment nor to soil is intended during the life cycle of the test substance. Indirect exposure to the environment is unlikely, which is also indicated by the manufacturing process. Furthermore, even if an unintended exposure would occur (e.g. via an accident), the substance is considered partially biodegradable (according to German Umweltbundesamt, UBA) and would not be persistent in the environment. In accordance with REACH, Annex IX, Section 9.2.1.4, column 2, this endpoint can be waived.