Registration Dossier

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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Both TAME and MTBE are not expected to hydrolyse under environmentally relevant pH conditions (pH 4-10) based on their physical-chemical properties and the properties of other structurally related aliphatic ethers (Lyman et al., 1982; Prager, 1992). Since ETBE is structurally highly related to both substances it can be expected that also ETBE will not significantly hydrolyze in natural waters.

According to existing data, degradation half-life of ETBE in the air is 3-12 days depending on environmental conditions (predominantly OH-radical concentration).

Using a degradation rate constant of 3.0E-12 cm3/molecule/s and an OH –radical concentration of 5E05 radicals/cm3 a half-life of 5.35 days is calculated (Bennett and Kerr, 1990).

Direct photolysis will not be an important removal process since aliphatic ethers do not absorb light at wavelengths >290 nm. The UV-spectrum (max at 289 nm) indicates that direct photolysis in water may not occur.

The abiotic degradation rate constants used in the assessment are sumamrised in the following table:


Degradation for hydrolysis

0 d-1

Degradation for photolysis

0 d-1

Degradation in air

0.130 d-1