Registration Dossier

Environmental fate & pathways

Biodegradation in water: screening tests

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

In a test on ready biodegradability, the substance showed a biodegradation of 52 % within 28 days. Therefore the substance is considered to be "Not Readily Biodegradable" (Mueller, 2000). 
In another test on inherent biodegradability the substance showed 71 % degradation after 28 days (Neuhahn, 2010).

Key value for chemical safety assessment

Biodegradation in water:
under test conditions no biodegradation observed

Additional information

A study on ready biodegradability was conducted in accordance with the Council Directive 92/69/EEC Method C.4-E. This test method is in all essential parts identica1 with OECD Guideline 301 D. The test substance in a mineral medium was inoculated with secondary effluent and incubated for 28 d under aerobic conditions in completely full, closed bottles. During this period the biodegradation was followed by analysis of dissolved oxygen. The amount of oxygen taken up by the test chemical, corrected for uptake by the blank inoculum run in parallel, was expressed as a percentage of theoretical oxygen demand (ThOD) or chemical oxygen demand (COD). Within 28 days, a biodegradation of 52 % was determined. Therefore the substance is considered to be "Not Readily Biodegradable".

A study on inherent biodegradability was conducted in accordance with the OECD Guideline 302C “Inherent Biodegradability: Modified MITI Test (II)” (1981) - based on standard operating procedures for OECD Guideline 301F (1992) and the Council Regulation (EC) No 440/2008, method C.4-D “Manometric Respirometry Test” (2008). A suspension of the substance in a mineral medium was inoculated with 40 % sludge of each of two different municipal sewage treatment plants (STP) and 20 % sludge of an industrial STP and incubated under aerobic conditions. During this period, degradation was followed by continuous automated BOD determinations. The test substance showed 71 % degradation after 28 days. Therefore the substance is considered to be “Inherently Biodegradable” but not fulfilling all specific REACH screening criteria (according to REACH Annex XIII: PBT Assessment) for not being assigned as P (= persistent substance), because degradation of the test item was less than 70 % within 14 days.