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Environmental fate & pathways

Phototransformation in air

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Description of key information

The tropospheric half-life of m-cresol is approximately 6 h due to degradation by OH radicals with an average concentration of 500000 radicals/mL .
An even shorter half-life of 3.8 h is calculated for m-cresol from smoke chamber experiments at different tempertures.

Key value for chemical safety assessment

Half-life in air:
6 h

Additional information

In the atmosphere, m-cresol will react with photochemically produced hydroxyl-radicals. In his critical review Atkinson recommended values for the reaction constant kOH at room temperature of 6.4 x 10-11 cm³ x molecule-per second. Based on a tropospheric OH radical concentration of 5 x 105molecules per cm³ a corresponding half-life of 6.0 h can be calculated.

In an experiment the temperature dependency of the reaction constants in a smog chamber was determined. The calculated half-life is 3.8 h for m-cresol at 23°C.