Registration Dossier

Diss Factsheets

Environmental fate & pathways

Biodegradation in water: screening tests

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

Not readily biodegradable, OECD 301 B, EU Method C4-C, Calmels 1995
Not readily biodegradable, OECD 301 B, EU Method C4-C, Licata-Messana 1998

Key value for chemical safety assessment

Additional information

Two biodegradation studies have been provided on a weight of evidence basis, Calmels (1995) and Licata-Messana (1998). A key study has not been selected as both studies are equally reliable and performed under GLP conditions and in accordance with the standardised guidelines OECD 301 B and EU Method C4-C. Based on the principles for assessing data quality as defined in Klimisch et al. (1997), both studies were assigned reliability scores of 1.

The ready biodegradability of the test material was determined in both studies in a carbon dioxide evolution test according to the modified Sturm method.Activated sludge was exposed to the test material over 28 days at a nominal concentration of 42.87 mg/L (15 mg TOC/L) under aerobic conditions. Released carbon dioxide was trapped in barium hydroxide and incorporated as barium carbonate (BaCO3). Samples were measured and analysed for CO2 production by back titration.

The degradation of the test material was evaluated by comparing the total mean amount of CO2 produced by the test media (corrected for that derived from the control media), with the total amount of CO2 that the test material could have theoretically produced (based on the carbon content of the test material (0.3499 to 0.3708 mg TOC per mg of test material).

Under the conditions of the Calmels (1995) test, 15 % biodegradation was observed over the 28 days. Under the conditions of the Licata-Messana (1998) test, biodegradation of the test material over 28 days was determined to be 7 %. Therefore based on these results the test material is considered to be not readily biodegradable.