Registration Dossier

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.