Fatty acids, C14-18 and C18-unsatd., branched and linear, esters with pentaerythritol

Biodegradation in water: screening tests

Description of key information

Readily biodegradable: 66.4 - 73.3% (CO2 evolution) after 28 d (OECD 301B); 76% (CO2 evolution) after 29 d (OECD 301B)

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Additional information

Since no studies investigating the biodegradability of Fatty acids, C16-18 (even numbered) and C18-unsatd., branched and linear, tri- and tetraesters with pentaerythritol are available, in accordance to Regulation (EC) No 1907/2006 Annex XI, 1.5 a read-across to the structurally related source substances 2,2-bis[[(1-oxoisooctadecyl)oxy]methyl]-1,3-propanediyl bis(isooctadecanoate) (CAS 62125-22-8) and Fatty acids, C16-18 and C18-unsatd., tetraesters with pentaerythritol (CAS 68604-44-4) was conducted. The source substances are representative to evaluate the biodegradability of the target substance. The target substance is mainly characterized as a tetraester of pentaerythritol and C16-C18 branched, saturated and unsaturated fatty acids. The source substance 2,2-bis[[(1-oxoisooctadecyl)oxy]methyl]-1,3-propanediyl bis(isooctadecanoate) (CAS 62125-22-8) is a tetraester of pentaerythritol and mainly C18 branched fatty acids as well as fatty acids of C14-C22. Fatty acids, C16-18 and C18-unsatd., tetraesters with pentaerythritol (CAS 68604-44-4) is mainly characterized as a tetraester of C18 unsaturated fatty acids.

The first study with the source substance 2,2-bis[[(1-oxoisooctadecyl)oxy]methyl]-1,3-propanediyl bis(isooctadecanoate) (CAS 62125-22-8)was conducted under aerobic conditions according to OECD 301B (GLP) using non-adapted activated sludge as inoculum. A test concentration of 15.5 – 15.6 mg/L was applied. Based on the CO2 evolution a biodegradation of 66.7 – 73.3% wasobserved after 29 days. For substances with different chain lengths the 10-day window should not be used for the interpretation of results. It is possible that a sequential biodegradation occurred which might have resulted in a prolonged lag-Phase and therefore a slower biodegradation period, although the test substance was biodegraded in a large amount after the test duration. In this case the pass level of > 60% can be applied after 28 days and therefore the test substance is considered to be readily biodegradable according to the OECD criteria.

The study with the second source substance fatty acids, C16-18 and C18-unsaturated, tetraesters with pentaerythritol (CAS 68604-44-4) was conducted according to OECD 301B as well. Non-adapted activated sludge was used as inoculum. A test concentration of 22.8 mg/L (TOC) was applied. Based on the CO2 evolution a mean biodegradation of 76% was observed after 28 days meeting the 10-day window. Hence, the substance is determined to be readily biodegradable according to OECD criteria.

Based on the available results from structurally related read-across substances (in accordance to Regulation (EC) No 1907/2006 Annex XI, 1.5) which are characterized by a comparable structure, it can be concluded that Fatty acids, C16-18 (even numbered) and C18-unsatd., branched and linear, tri- and tetraesters with pentaerythritol is readily biodegradable according to the OECD criteria.