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Description of key information

 DT50 = 21.664 h (AOPWIN, v. 1.91, 2000 by U.S.-EPA based upon QSAR methods)

Key value for chemical safety assessment

Additional information

The half-life of Chlorophene (CAS 120-32-1) in air due to indirect photodegradation, i.e. oxidation with photochemically produced hydroxyl radicals, was calculated using the software programme AOPWIN, v. 1.91, 2000 by U.S.-EPA based upon QSAR methods developed by Dr. Roger Atkinson and co-workers. AOPWIN requires only a chemical structure to make these predictions. Structures are entered into AOPWIN by SMILES (Simplified Molecular Input Line Entry System) notations.

With the improved version 1.91, the half-life of chlorophene in the troposphere was calculated to be 21.664 hours with a degradation rate of 17.774E-12 cm3 * molecule-1 * s-1. These estimations were carried out with respect to the OH radical reaction, only, and using a 24-hours-day with 5 x 105 OH radicals/cm3 (Fàbregas, 2005).

Based on the vapour pressure and the Henry’s Law constant (calculated, 3.7 x 10-3 Pa m³/mol), no significant volatilisation of chlorophene is to be expected. Calculations of the chemical lifetime in the troposphere resulted in a half life of 21.664 hours. According to these results (DT50 < 2 days), Chlorophene is rapidly degraded by photochemical processes and no accumulation of chlorophene in the air is to be expected.

 

Stability of chlorophene in air

Type of test

Method

Results

Reference

Indirect photodegradation

QSAR-calculation,

AOPWIN, v. 1.91, 2000

DT50 = 21.664 hours

24h-average OH-conc.: 0.5 x 106 per cm³

Fàbregas (2005)