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Environmental fate & pathways

Phototransformation in water

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Description of key information

In water, 2-mercaptoethanol will be degraded by indirect photodegradation with OH radicals within 4.7 to 393 days, depending on the concentration of the OH radicals.

Key value for chemical safety assessment

Additional information

The rate constant for the reaction between hydroxyl radicals and

2-mercaptoethanol in aqueous solution at pH 6.5 has been experimentally

determined to be 6.8*10E+9 l/Mol*sec. Assuming that the hydroxyl radical

concentration (according to Zepp et al., 1987) for the small lake Greifensee

in Switzerland reaches 2.5E-16 mol/l in the summer time at noon near the

surface and 3.0E-18 mol/l for the whole water column (14 m) over the whole year

the half-life for this reaction would be 4.7 - 393 days, respectively