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Description of key information

No specific toxicokinetic study is available on the UVCB substance.
The substance is an UVCB generated by the reaction of isophorone diamine, butyl 2,3-epoxypropyl ether and BisphenolA diglycidylether. It is expected that the starting materials or their hydrolysis products are released in the course of metabolism. Epoxy hydrolase present in the skin, in the intestinal tissues and in liver and plasma can efficiently cleave similar epoxide.

Key value for chemical safety assessment

Bioaccumulation potential:
no bioaccumulation potential

Additional information

Isophorone diamine (IPDA) measured as as IPDA-pentafluoropropionic anhydride in humans exposed to IPDI by inhalation. The optimal hydrolysis condition was found giving the highest yield of IPDA in urine (hydrolysis with 3M NaOH during 4 h). The average urinary elimination half-time was 2.8 hours. The average  urinary excretion was 27 % (range 19-46%). An association between the  estimated inhaled dose and the total excreted amount was seen. When working up samples from exposed persons without hydrolysis, no isophorone diamine (IPDA) was seen. This means, that no free IPDA was present in the urine after exposure to IPDI. Hence, IPDA is covalently bonded in urine. No IPDA could be found in hydrolysed plasma ( ca 0.1µg/l), which could not be explained.

(Tinnerberg H, Skarping G, Dalene M and Hagmar L,

Test chamber exposure of humans to 1,6-hexamethylene diisocyanate and isophorone diisocyanate, 1995)

Higher molecular weight molecule (MW 1000 and greater) are not bioavailable and therefore not expected to bioaccumulate.

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