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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

According to a Mackay Level I model calculation the main target compartments for isophorone diisocyanate cyclodimer will be sediment and soil (50 % each). Similar behaviour is expected for the higher oligomers. The calculated Henry’s law constant of 0.63 Pa m3/mol indicates low volatility of isophorone diisocyanate cyclodimer from surface waters. Similar behaviour is expected for the higher oligomers. However, due to rapid hydrolysis no equilibrium partitioning in the environment can be established. With a calculated Koc of 2,233,000 l/kg, the sorption potential of isophorone diisocyanate cyclodimer to soil or sediment organic matter is expected to be very high (Blume scale). Even higher values are expected for the higher oligomers. However, they are all not relevant because of the rapidy hydrolysis of all the oligomers.


The QSAR calculated rate constant for the OH sensitized photodegradation of isophorone diisocyanate cyclodimer is approximately 2.68E-11 cm3/(molecule * s). At 500,000 OH radicals / cm3 (approximate 24-hour mean in central Europe), this corresponds to a half-life of 14.4 hours. Higher oligomers have more reactive functions and therefore a lower half-life will be calculated. The substance was not found readily biodegradable but hydrolysis with a half-life of approximately 4 hours is expected. In view of the partitioning behaviour, hydrolysis is predicted to be the predominant mechanism of removal from the environment. Hydrolysis also inhibits bioaccumulation that might be expected in view of the QSAR calculated partition coefficient 1-octanol/water of log Kow = 9.73.