Registration Dossier

Environmental fate & pathways

Biodegradation in water: screening tests

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

Readily biodegradable: 89.9% after 29 d (OECD 301B)
Readily biodegradable: 75.3% after 28 d (OECD 301C)

Key value for chemical safety assessment

Biodegradation in water:
readily biodegradable

Additional information

Since no studies investigating the ready biodegradability of tetradecyl stearate (CAS 17661-50-6) are available for this endpoint, in accordance to Regulation (EC) No 1907/2006 Annex XI, 1.5 a read-across to the structurally related source substances 9-Octadecenoic acid (Z)-, C12-15-alkyl esters (CAS 68412-06-6) and docosyl docosanoate (CAS 17671-27-1)was conducted. The read-across substance is representative to evaluate the biodegradation of tetradecyl stearate. 9-Octadecenoic acid (Z)-, C12-15-alkyl esters (CAS 68412-06-6) is an ester of an unsaturated C18 fatty acid esterified with a C12-C15 linear alcohol.Docosyl docosanoate (CAS 17671-27-1) is characterised as an ester of mainly linear C22 fatty acid esterified with a linear C22 alcohol. Using both source substances allows for interpolation to the target substance. They cover the upper and lower end of C-chains of the fatty acid and the alcohol.A detailed analogue approach justification is provided in the technical dossier (see IUCLID Section 13).

The study with the source substance 9-Octadecenoic acid (Z)-, C12-15-alkyl esters was performed according to OECD 301B (GLP) under aerobic conditions using non-adapted domestic activated sludge as inoculum (Flach, 2011). A test substance concentration of approx. 20 mg/L (based on TOC) was degraded to an extent of 89.9% after 29 d meeting the 10 d window. Thus, the substance is readily biodegradable according to the OECD criteria.

The second study with the source substance docosyl docosanoate (CAS 17671-27-1) was performed according to OECD 301C (GLP) under aerobic conditions using a mixture of activated sludge from STP with freshwater from rivers and lakes, marine water and marine sediment as inoculum with a test substance concentration of 100 mg/L (Ministry of Economy, Trade and Industry, Japan, 1992). A biodegradation of 75.3% (BOD) was observed after 28 d. Since the substance reached the pass level for OECD 301C (biodegradation is > 60% after 28 d, no 10-day window required) docosyl docosanoate is readily biodegradable according to the OECD criteria.

Based on the results from two structurally related read-across substances (in accordance to Regulation (EC) No 1907/2006 Annex XI, 1.5) it can be concluded that tetradecyl stearate is readily biodegradable according to the OECD criteria.