The Henry's Law constant for methyl benzoate is estimated as 3.24X10-5 atm-cu m/mole(SRC) derived from its vapor pressure, 0.38 mm Hg(1), and water solubility, 2.1X10+3 mg/L(2). This Henry's Law constant indicates that methyl benzoate is expected to volatilize from water surfaces(3). Based on this Henry's Law constant, the volatilization half-life from a model river (1 m deep, flowing 1 m/sec, wind velocity of 3 m/sec)(3) is estimated as 22 hours(SRC). The volatilization half-life from a model lake (1 m deep, flowing 0.05 m/sec, wind velocity of 0.5 m/sec)(3) is estimated as 14 days(SRC). Methyl benzoate's Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC). Methyl benzoate is not expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 0.38 mm Hg(1).
Literature: (1) Daubert TE, Danner RP; Data Compilation Tables of Properties of Pure Compounds New York, NY: Amer Inst for Phys Prop Data (1989) (2) Riddick JA et al; Organic Solvents 4th ed. New York, NY: Wiley (1986) (3) Lyman WJ et al; Handbook of Chemical Property Estimation Methods. Washington, DC: Amer Chem Soc pp. 15-1 to 15-29 (1990)
The adsorption of methyl benzoate was determined by a modified version of the OECD guideline 106, a batch equilibrium method, in three soils with different characteristics: an acid forest soil (Podzol), an agricultural soil (Alfisol), and a sediment. The respective Freundlich constants, Kf (1/n), for the three soils were 8.64 (0.81), 1.29 (0.85), and 1.51 (0.84)(1). Koc values for the Podzol, Alfisol and sediment were 178, 103, and 95, respectively(1). Methyl benzoate also has a reported log Koc value of 2.10 (Koc = 126)(2). Using a structure estimation method based on molecular connectivity indices(3), the Koc of methyl benzoate can be estimated to be 70(SRC). According to a classification scheme(3), methyl benzoate is expected to have moderate to high mobility in soil.
Literature: (1) Von Oepen B et al; Chemosphere 22: 285-304 (1991) (2) Schuurmann G et al; Environ Sci Technol 40: 7005-11 (2006) (3) Swann RL et al; Res Rev 85: 17-28 (1983)