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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

ETBE can not be regarded as readily biodegradable in standard test systems (Fayolle et al., 1998; Slovnaft VÚRUP, a.s., 2005a). However, certain adapted micro-organisms are capable of degrading ETBE (e.g. Cowan and Park, 1996; Steffan et al., 1997; Kharoune et al., 1998, Kharoune et al., 2001; 2002).

It may be concluded that ETBE is inherently biodegradable under certain conditions in aquatic aerobic environment. However, the non-standard test data available indicate that ETBE degradation might not fulfil the test criteria (OECD 302). Therefore, in the further assessment the substance is assumed to be “Inherently biodegradable, not fulfilling criteria” for professional and consumer releases and on the regional scale.

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 ETBE 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 “Readily biodegradable” and the Monod kinetics are used for the degradation of ETBE 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.


In anaerobic, static sediment/water microcosms, ETBE does not biodegrade (Suflita et al., 1993; Mormile et al., 1994).


Several studies are available for degradation of ETBE in soil. The results are conflicting. In a study in which soil was polluted with gasoline containing ETBE it was shown that aerobic biodegradation was observed after the spill (Yuan, 2006). However, other studies concluded that rapid and reliable biodegradation of ETBE in soil can not be assumed under any normal environmental conditions (both aerobic and anaerobic), indicating very slow degradation in soil (Yeh and Novak, 1994; Allard et al., 1996; Reisinger et al., 2000).As the study by Yuan (2006) was better in design and reporting than the other studies mentioned,the worst-case half-life of 89.5 days in soil from this study is used in the assessment.


The rate constant used in the assessment are:

Degradation in a non-adapted STP

0 d-1

Degradation in an adapted STP

Monod kinetics (default values)

Biodegradation in water

4.62E-03 d-1

Biodegradation in aerated sediment

2.31E-03 d-1

Biodegradation in soil

4.08E03 d-1