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Administrative data

Link to relevant study record(s)

Description of key information

DT50 (photolysis): 0.7 hour (OECD proposal, 2000; Meinerling and Herrmann, 2007)

Key value for chemical safety assessment

Additional information

A study on photolysis of Chlorophene (CAS 120-32-1) in water was conducted by Meinerling and Herrmann (2007). The test was performed according to “OECD Proposal for a new guideline, Phototransformation of Chemicals in Water – Direct and Indirect Photolysis, August 2000”. Chlorophene was incubated in aqueous buffer solution (pH 7) at a concentration of 5 mg/L over a time interval of 5 days (first experiment) and 4 hours (second experiment). The temperature during the study was maintained within the range of 20 to 30 °C. For technical reasons, the temperature during the first experiment was > 30 °C. Samples were either kept in the dark or exposed to a filtered xenon arc lamp. Residues of chlorophene were analysed by HPLC. Chlorophene concentration rapidly dropped from an initial value of 99.4% to 0% of applied dose after 48 hours in the 5 days experiment and from an initial value of 99.7% to a low value of 4.3% of applied dose by 4 hours in the 4 hours experiment. Under non-irradiated conditions, the mean parent concentration is not significantly reduced. The aqueous photolysis half-life of chlorophene was calculated to be 0.7 hours.Therefore, photolysis will contribute to the overall degradation of chlorophene in aquatic systems.

Photodecomposition of chlorophene in water

Guideline Test method

Initial TS concen­tration

pH value of the medium

Photolysis rate constant (kcp)

Direct photolysis sunlight rate constant (kpE)

Reaction quantum yield (fcE)

Half-life (DT50)

Degra-dation products


OECD 2000*

5 mg a.s./L


0.98 [1/h]

11.97 [1/day].


0.7 h (experi-mental)

Not determined

Meinerling and Herrmann, 2007

*OECD Proposal for a new Guideline, Phototransformation of Chemicals in Water – Direct and Indirect Photolysis, August 2000