Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

The adsorption coefficient (Koc) on soil of the substance was calculated using the computer program KOCWIN (v2.00). It is predicted that the substance has a Koc of 10 L/Kg.According to the McCall classification scheme, a Koc of 10 L/Kg means that 1,2,3,6-tetrahydro-3-methylphthalic anhydride would be regarded as very highly mobile (0<Koc<50) in soil.

The Henry's Law constant value of 2.55 Pa-m3/mole indicates that the substance is moderately volatile from surface water.

Distribution in environmental compartments has been calculated using a Fugacity model according to Mackay, Level III. Distribution in various environmental compartments is estimated as: Air - 0.187%; Water - 40.6%; Soil - 59.1% and Sediment - 0.0914%. However, the substance is known to be unstable, rapidly hydrolysing to the corresponding di-carboxylic acid in aqueous media and this process is expected to occur in the environment should release occur. As a result the calculated distribution may not be a reasonable estimate. Similar modelling of the degradation product of the substance, 3-methylcyclohex-4-ene-1,2-dicarboxylic acid, estimated distribution in the various environmental compartments as: Air - 0.00026%; Water - 19.9%; Soil - 80% and Sediment - 0.119%. Refinement of the modelling, undertaken as part of the CSA, and taking account of the uses of the substance, does not support these estimates.