Registration Dossier

Environmental fate & pathways

Biodegradation in water: screening tests

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

Study and literature data on cresols and ethylphenols show  them to be readily biodegradable. Study data on xylenols show  that 2,3- and 2,4-xylenol are readily biodegradable and the remaining 4 are inherently biodegradable (Pitter, 1976). Based on all available information for cresols, ethyl-phenols and xylenols the substances are described as inherently biodegradable. 

Key value for chemical safety assessment

Biodegradation in water:
inherently biodegradable

Additional information

m-, p- and o-Cresol is inherently degradable as shown by a test similar to OECD guideline 302 B with a removal of 95 -96 % of m-cresol after 5 days of incubation. The degradation rates were >15 mg COD/g/h which was the criteria for being readily biodegradable.

Ethyl phenols are considered to be readily biodegradable. The sensitivity of the test system was confirmed as the reference substance sodium benzoate is considered to be readily biodegradable

The xylenols are inherently degradable as shown by a test similar to OECD guideline 302 B with a removal of 89.3 -97.5 % after 5 days of incubation . 2,3 -xylenol and 2,4 -xylenol had degradation rates >15 mg COD/g/h which was the criteria for being readily biodegradable (Pitter 1976)

A recent 301D study (2010) on mixed xylenols showed biodegradation of 39 % in 28 days. However, this test is very stringent and it does not necessarily mean that the substance would not biodegrade under environmental conditions.