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Environmental fate & pathways

Hydrolysis

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Administrative data

Link to relevant study record(s)

Description of key information

The endpoint hydrolysis is covered by read across. The hydrolysis half-life was always clearly below 12 hours at room temperature (22 -23 °C). Both acidic and basic media appear to accelerate the hydrolysis. No simple relationship between the rate of hydrolysis and the concentration of the organic co-solvent acetonitrile could be observed (AQura, 2010). In another study a decrease of 81 % within 0.65 hours at 50°C was determined. The substance hydrolysed rapidly in water with a calculated half-live of approx. 2.7 hours at 25 °C (Feldhues, 2007). The results are based on the analogous substance 3-Isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate homopolymer, isocyanurate type (CAS 53880 -05 -0).

Key value for chemical safety assessment

Half-life for hydrolysis:
12 h
at the temperature of:
22 °C

Additional information

"Should read: < 12 hours measured at 22-23 °C"

According to experience with the substance itself as well as with diisocyanates and similar polyisocyanates, the amines formed in the initial hydrolysis step, which is associated with elimination of carbon dioxide, have a high reactivity towards unreacted isocyanate. The consequence is that in the hydrolysis of isophorone diisocyanate oligomer predominantly polyurea molecules are formed. They are insoluble in water and thereby have a negligible mobility (including accumulation potential) in the environment.