Clorofene

Hydrolysis

Description of key information

At pH 7 at 50.8°C: 6.5% loss in 5 days, Rate constant: 0.0156 d-1, Half life: 44.4 days (Greenwood 2003; EU method Annex V, C7 (92/69/EEC)).

At pH 9 at 50.8°C: 2.1% loss in 5 days, Rate constant: 0.0186 d-1, Half life: 37.4 days (Greenwood 2003; EU method Annex V, C7 (92/69/EEC)).

Additional information

One study was performed according to EU method Annex V, C7 (92/69/EEC) regarding the hydrolysis of test item Chlorophene (CAS 120-32-1). The hydrolysis of chlorophene was studied by Greenwood (2003) in sterile aqueous buffered solutions at pH 4, 7 and 9. The concentrations of chlorophene were measured via HPLC-UV. In the preliminary test at 50 °C, the percentage of chlorophene which was hydrolysed during 5 days was less than 10%:6.5% loss was found at pH 7 and 2.1% at pH 9. No loss was found at pH 4. According to the guideline, the test substance is considered to be hydrolytically stable. Therefore, no further testing is required. The estimated half-lives of BCP at pH 7 and 9 were 44.4 and 37.4 days. Considering the hydrolytic stability determined under stringent temperature conditions and at different pH values (pH 4, 7 and 9) it is not expected that hydrolytic processes will contribute to the degradation of chlorophene in the aquatic systems. Hydrolysis is expected not to be a major degradation pathway for chlorophene.

Table: Results of hydrolysis of chlorophene

Guideline / Test method	pH	Temp. [°C]	Initial TS concentration, C0 [mg/L]	Reaction rate constant, Kh [d]	Half-life, DT50 [d]	Coefficient of correlation, r2	Reference
EU method Annex V, C7 (92/69/EEC)	4, 7, 9	50	62.5 mg a.s./L	pH 4: no dissipation pH 7: 0.0156 day-1 pH 9: 0.0186 day-1	pH 4: no dissipation pH 7: 44.4 days pH 9: 37.4 days	n.a.	Greenwood (2003)