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Environmental fate & pathways

Biodegradation in water: screening tests

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Description of key information

TAEE is characterised as “inherently biodegradable, not fulfilling criteria”.

Key value for chemical safety assessment

Biodegradation in water:
under test conditions no biodegradation observed

Additional information

One GLP-compliant Closed Bottle test (OECD 301D) is available for TAEE (Harlan Laboratories Ltd, 2008). The percentage of biodegradation observed is ca. 5% after 28 days. In a GLP-compliant Closed Bottle test (OECD 301D) with the structurally related aliphatic ether TAME (Hazleton Europe, 1995) ca. 4% biodegradation after 28 days was observed.Thus, TAEE is not readily biodegradable in the aquatic environment according to this standardised aerobic ready-biodegradation tests.

However, certain adapted micro-organisms are capable of degrading the structurally related (see reporting format for the analogue approach as attached to the respective IUCLID entry) aliphatic ether TAME (Kharoune et al., 2002). This study shows that at least some microbial species are capable to degrade the structurally related aliphatic ether TAME and to use it even as their sole carbon source. It may be concluded that adapted sewage sludge is able to degrade TAME.

It may be concluded that TAEE is not biodegradable under certain conditions in the aquatic aerobic environment. Therefore, in the further assessment TAEE is assumed to be“inherently biodegradable, not fulfilling criteria”for professional and consumer releases.

There is good evidence for ready biodegradability when sewage sludge has become adapted to the substance. Such conditions will apply where there are continuous releases of TAEE to a STP, such as for large production and processing sites. Thus, the substance can be assumed to be readily biodegradable in such cases. Therefore the characterisation of biodegradability in such STPs is set at“inherently biodegradable, not fulfilling criteria”and the Monod kinetics are used for the degradation of TAEE in the STP instead of the more simplified first-order kinetics as it can be assumed that the STPS at industrial site are carrying adapted sludge only.