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Environmental fate & pathways

Phototransformation in air

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Description of key information

The substance is removed rapidly from the atmosphere with a calculated half-life of less than 2 d.

Key value for chemical safety assessment

Half-life in air:
4.967 d

Additional information

Phototransformation is estimated by the Atmospheric Oxidation Program for Microsoft Windows (AOPWIN) of the US EPA. In the first step, it estimates the rate constant for the gas-phase reaction between hydroxyl radicals and the organic chemical. For olefinic/acetylenic compounds the rate constant for the gas-phase reaction with ozone is determined In the second step. In the third step, using the average atmospheric concentrations of photochemically formed hydroxyl radicals and ozone, the atmospheric half-lives for organic compounds are calculated from the respective rate constants. Most reaction rate constants are taken from the publications of Atkinson and co-workers. The calculations suggest that the substance is removed rapidly from the atmosphere with a calculated half-life of less than 5 d.