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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

The Henry's Law constant (H) is calculated as 69.8 Pa m3/mol (log H = 1.84), based on a vapour pressure of 33 kPa at 25 °C and a water solubility of 42,000 mg/l at 25 °C in EUSES, this corresponds to a Henry's Law constant of 33.3 Pa m3/mol at environmental temperature.

The organic carbon-water partitioning coefficient (Koc) calculated from the octanol-water partition coefficient (log Kow = 1.06) using the equation from the TGD (predominantly hydrophobics) is 9.1 l/kg (log value = 0.95). This predicted value is used in the assessment.

The Level I fugacity model is used to calculate the theoretical distribution of MTBE between four environmental compartments (air, water, soil, sediment) at equilibrium in a unit world. The model calculates that 93.9% of MTBE partitions to the atmosphere.