Registration Dossier

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: 40.2 – 42.3% in 28 days (OECD 301B) 

Key value for chemical safety assessment

Additional information

One study investigating the ready biodegradability of 1,2,3-propanetriyl triisooctadecanoate (CAS 26942-95-0) is available. The study was conducted according to OECD guideline 301B (GLP) under aerobic conditions using domestic activated sludge as inoculum (Desmares-Koopmans, 1996). The inoculum was exposed to a substance concentration of 15.5 mg/L for 28 days. The biodegradation rate was determined by measuring the CO2 evolution of the inoculum. A degradation rate of 40.2 – 42.3% was determined at test termination. An initial delay in CO2 production in the toxicity control was observed, which can be an indication of a toxic effect on the microorganisms. However, the CO2 production recovered during the test period. Hence the inhibiting effect of the test substance was on the borderline of the toxicity criteria (25 %). It can be expected that such a slight inhibiting effect of the test substance on microbial activity does not lead to a change in the final result. Generally free fatty acids have been demonstrated to be rapidly and extensively biodegraded in aerobic systems in the environment (e.g. Swisher, 1987). Thus, biodegradation of the single components of the target substance in the environment is likely.

Swisher RD (1987). Surfactant Biodegradation, Marcel Dekker, New York. Biodegradability of fatty acids, pp. 826-827