Registration Dossier

Environmental fate & pathways

Biodegradation in water: screening tests

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

There are 2 key studies available to fulfil this endpoint, the Schörbel, 1992 study adresses ready biodegradability and the Mead & McKenzie, 2005 study adresses inherent biodegradability.
Ready biodegradability:
The test material showed limited biodegradation (25% degradation at 10 mg/L and 6% at 20 mg/L) over 28 days in a ready (OECD 301B) biodegradation study (Schörberl 1992a). The study was conducted using unadapted inoculum from a municipal sewage plant. The positive control, sodium benzoate, attained 95% degradation after 28 days indicating viability of the inoculum.
The results of the study indicate that the test material is not readily biodegradable.
Inherent biodegradbility:
A study was performed to assess the inherent biodegradability of the test material in an aerobic aqueous medium. The method followed the recommendations of CONCAWE (October 1999) "A Test Method to Assess the Inherent Biodegradability of Oil Products" and the draft OECD Guideline (October 2001) No 302D "Inherent Biodegradability: CONCAWE Test".
The test material attained 10% biodegradation after 56 days based on carbon dioxide production and therefore cannot be considered to be inherently biodegradable.
The results of the compound specific analyses indicated that no significant chemical or biological degradation of the test material occurred.

Key value for chemical safety assessment

Biodegradation in water:
under test conditions no biodegradation observed

Additional information

There are 2 key studies available to fulfil this endpoint, the Schörbel, 1992 study adresses ready biodegradability and the Mead & McKenzie, 2005 study adresses inherent biodegradability.

The Mead & McKenzie study is considered to have a reliability rating of 1, according to the criteria of Klimisch, 1997. This was conducted according to the draft OECD Guideline 302 D (Inherent Biodegradability - Concawe Test).

The Schörbel study is considered to have a reliability rating of 2, according to the criteria of Klimisch, 1997 as the inoculum concentration not mentioned and the composition of test medium was not specified.

The test material is neither readily nor inherently biodegradable according to the two key studies.