Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

For a registration under REACH at a tonnage band for 100 - 1000 tonnes, information about the hydrolytic behaviour has to be provided. The computer program HYDROWIN v2.00 (by US-EPA) estimates the hydrolysis rate constants for specific organic classes and, furthermore, hydrolysis half-lives under typical environmental conditions. The prediction for tributyl citrate indicated that esters were detected as hydrolysable substance class with half-lives of 1.92 years at pH 8 and 19.18 years at pH 7, thus the substance can be considered as hydrolytically stable.

The phototransformation in air was calculated with the computer program AOPWIN (v1.92a) program made available by the U.S. Environmental Protection Agency. For tributyl citrate an overall OH rate constant (gas-phase reaction constant) of 16.04 E-12 cm3/molecules-sec and a half-life of 0.67 days (8.00 hours) was calculated, assuming a 12- hr day with an OH rate constant of 1.5 E6 OH/cm³. Reaction with N, S and –OH is estimated to be 0.14 E-12 cm3/molecules-sec, no ozone reaction is estimated for the compound. The assumed “Hydrogen Abstraction” gives a value of 15.90 E-12 cm³/molecule-sec, which is almost equal to the overall OH rate constant of the compound. All calculations were performed supposing a surrounding temperature of 25 °C. Thus it can be concluded that the substance will be rapidly degraded in air.