Registration Dossier

Environmental fate & pathways

Hydrolysis

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

Experimental rate constant value at pH 4: not applicable
Experimental estimated half-life at 25°C at pH 4: > 1year
Experimental rate constant value at pH 7: 7.75 x
10-8
Experimental estimated half-life at 25°C at pH 7: 106 days
Experimental rate constant value at pH 9: 5.72 x
10 -6
Experimental estimated half-life at 25°C at pH 9: 33.7 hours

Key value for chemical safety assessment

Half-life for hydrolysis:
106 d
at the temperature of:
25 °C

Additional information

The determination was carried out according Method C7 Abiotic Degradation, Hydrolysis as Function oh pH of Commission Regulation (EC) 440/2008 of 30 May 2008, Method 111 of the OECD Guidelines for Testing of Chemicals, 13 April 2004 and GLP. No deviations from the Guidelines were observed.

The test item was dissolved in an aqueous solution at a specific pH value and incubated in the dark at a controlled temperature. The concentration of the test item was them determined as a function of time, using HPLC analysis.

The hydrolysis observed was attributed to the base catalyzed cleavage of the ester functional group to give diethyoxyphosphinyl acetic acid and ethanol. Indeed, the rate of hydrolysis increases with an increase in pH, which was consistent with the proposed base catalyzed hydrolysis pathway for the ester functional groups.