Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

The adsorption coefficient (Koc) of hexahydrophthalic acid (HHPAc) was estimated, from KOCWIN using the LogKow (logD) method, to have a log10Koc value of -1.863 (equivalent Koc= 0.0137).

According to the McCall classification scheme of soil mobility potential, the substance would be regarded as very highly mobile (0 < Koc < 50) on soil.

The adsorption coefficient (Koc) of hexahydrophthalic anhydride (HHPA) was determined, using the HPLC method in accordance with OECD/EU test guidelines, to have a log10Kocvalue of 2.3 (equivalent Koc= 190). According to the McCall classification scheme of soil mobility potential, the substance would be regarded as having medium mobility in soil.

The Henry's Law constants of hexahydrophthalic acid (HHPAc), as hydrolysis product of cyclohexane-1,2-dicarboxylic anhydride (HHPA), was considered for the environmental assessment.

The value of 2.71E-4 Pa m³/mol shows that HHPAc is essentially non volatile from surface water.

Distribution in environmental compartments has been calculated using a Fugacity model according to Mackay, Level III, under the following emission scenario: 1000 kg/h into each of air and soil compartments.The soil (96.4%) was found to be the major target compartment.

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 hexahydrophthalic acid, under the following emission scenario: 1000 kg/h into each of air, water and soil compartments, leads to an estimated distribution in the various environmental compartments in which again the soil (65.2%) was found the major target compartment.