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

Readily biodegradable: 93% after 28 days (CO2 evolution, EU C.4-C)

Key value for chemical safety assessment

Biodegradation in water:
readily biodegradable

Additional information

The biodegradability of C12-18AS Na (CAS 68955-19-1) was investigated in a key, GLP guideline study according to EU method C4 (Diefenbach 1997). Activated, non-adapted sludge coming from a communal sewage treatment plant was used as inoculum. The initial concentration of the test substance was ca. 45 mg a.i./L, equal to ca. 16.5 mg/L of DOC. Biodegradation measured after 28 days as CO2 evolution reached 93%. It can be concluded that the substance is readily biodegradable according to OECD criteria.

In addition the biodegradability of C12-18AS Na (CAS 68955-19-1) was investigated in asupporting O2-consumption test, equivalent to OECD guideline 301 D (Richterich 2004). In this non-GLP-study 74 % degradation was reached after 30 days. Another supporting GLP study by Philpotts (1995) was performed according OECD guideline 301 B. Non-adapted inoculum originated from a lab-scale sewage plant. The biodegradation after 28 days reached 79% and 84% at the concentrations of the test substance 10 mg/L and 20 mg/L respectively. A non-GLP test by Finck (2000) was performed according to OECD guideline 301 D. A non-adapted activated sludge originating from a sewage treatment plant was used in this test. Biodegradation reached 73% after 28 days. Finally, inherent biodegradation test by P&G (1991) was preformed according to OECD guideline 302A and GLP principles. Settled sewage influent (ratio 1:3) from municipal sewage treatment plants receiving predominantly domestic sewage was used as inoculum. The concentration of test substance was 29 mg/L. Biodegradation reached more than 94% after 25 days and therefore the test substance is considered as inherently biodegradable.