Pesticide volatilisation rates: A new measurement of the vapour pressure of pentachlorophenol at room temperature

Abstract

AbstractThe rates of volatilisation of pentachlorophenol, gamma‐HCH and HEOD have been measured under the same conditions. The rates found indicate that the vapour pressure of pentachlorophenol at ambient temperatures is ∽ 10−6 mmHg, significantly lower than the widely quoted value ∽ 10−1 mmHg. This lower value accounts for the behaviour of pentachlorophenol better than the existing value, which was obtained by extrapolation of the results of high temperature experiments. It is suggested that the direct measurement of relative loss rates is a simpler method of measuring volatile loss than the measurement of vapour pressure and that the method may prove a useful alternative to vapour pressure measurements in the assessment of the environmental effects of chemicals, particularly for compounds of moderate volatility.