title: Correlation of chemical evaporation rate with vapor pressure.
abstract: A new one-parameter correlation is developed for the evaporation rate (ER) of chemicals as a function of molar mass (M) and vapor pressure (P) that is simpler than existing correlations. It applies only to liquid surfaces that are unaffected by the underlying solid substrate as occurs in the standard ASTM evaporation rate test and to quiescent liquid pools. The relationship has a sounder theoretical basis than previous correlations because ER is correctly correlated with PM rather than P alone. The inclusion of M increases the slope of previous log ER versus log P regressions to a value close to 1.0 and yields a simpler one-parameter correlation, namely, ER (μg m(-1) h(-1)) = 1464P (Pa) × M (g mol(-1)). Applications are discussed for the screening level assessment and ranking of chemicals for evaporation rate, such as pesticides, fumigants, and hydrocarbon carrier fluids used in pesticide formulations, liquid consumer products used indoors, and accidental spills of liquids. The mechanistic significance of the single parameter as a mass-transfer coefficient or velocity is discussed.
authors.affiliation: Environmental and Resource Studies, Trent University , 1600 West Bank Drive, Peterborough, Ontario K9J 7B8, Canada.
authors.forename: Donald
authors.initials: D
authors.lastname: Mackay
authors.forename: Ian
authors.initials: I
authors.lastname: van Wesenbeeck
mesh_terms: D007700:Kinetics; D009930:Organic Chemicals / Q000737:chemistry*; D013696:Temperature; D055548:Vapor Pressure; D014835:Volatilization
chemical_list: D009930:Organic Chemicals