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Environmental fate & pathways

Henry's Law constant

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Description of key information

Henry’s Law constants for the cresol isomers range between 0.087 Pa m³/mol and 0.15 Pa m³/mole.

Key value for chemical safety assessment

Additional information

The distribution of a gas between aqueous solution and air is described by the Henry’s law constant (HLC). With a column method a HLC of 0.15 Pa m³/mol was determined for o-cresol and a HLC of 0.087 Pa m³/mol for m-cresol at 25°C (Altschuh et. al, 1999). The HLC of p-cresol is reported to be 0.1 Pa m³/mol at 25 °C (Gaffney et. al, 1987). These values indicate a low volatility from aqueous solution according to the criteria of Thomas (1990).

Since the cresols are week acids Kow, Koc, HLC, and environmental distribution will depend on the pH of the aqueous phases. At basic pH, the vapour pressure of the cresols will be decreased.