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Environmental fate & pathways

Biodegradation in water: screening tests

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Description of key information

Readily biodegradable: 82.6% in 28 days (OECD 301B); read across

Key value for chemical safety assessment

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Experimental data investigating the biodegradability of Glyceryl undecylenate (CAS 123759-97-7) are not available. The assessment was therefore based on a weight of evidence approach. The WoE comprises a study conducted with the structural analogue substance Glycerides, C8-10, mono- and di- (CAS 85536-07-8; in accordance to Regulation (EC) No. 1907/2006 Annex XI, 1.5) and QSAR calculations for the main substance components. The target and the source substances are esters of a tri-functional alcohol (glycerol) with one or more carboxylic (fatty) acid(s) chain(s). The alcohol moiety (glycerol) is common to the analogue substances. The fatty acid moiety comprises carbon chain lengths from C8-C11 and includes mainly linear saturated alkyl chains, but also unsaturated chains bound to the alcohol, resulting in mono-, di-, and tri-esters. The read-across study was conducted according to OECD Guideline 301B, under GLP conditions (Flach, 2012). Activated sludge microorganisms were exposed to the test substance for a period of 28 days, and biodegradation followed by measuring the CO2 production in the test vessels. After 28 days, the test substance reached 82.6% biodegradation, and therefore, it can be considered as readily biodegradable. The results obtained in the toxicity control (81.1% biodegradation within 14 days) show that Glycerides, C8-10, mono- and di- is not toxic to and therefore non-inhibitory of activated sludge microorganisms activity.
The QSAR calculations were performed using the Ready biodegradability model (version 1.0.8) of VegaNIC version 1.0.8. The model predicted ready biodegradability for the main substance components (Birkhofer, 2015). All predictions are considered to be valid since the main substance components are within the training set of the model. Based on the weight of evidence approach Glyceryl undecylenate (CAS 123759-97-7) is considered readily biodegradable.