The Henry's Law constant for ethyl propionate is estimated as 2.51X10-4 atm-cu m/mole(SRC) from its vapor pressure, 35.8 mm Hg(1), and water solubility, 19,200 mg/l(2). This Henry's Law constant indicates that ethyl propionate 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 6 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 5 days(SRC). Ethyl propionate's estimated Henry's Law constant(1,2) indicates that volatilization from moist soil surfaces may occur(SRC). The potential for volatilization of ethyl propionate from dry soil surfaces may exist(SRC) based upon a vapor pressure of 35.8 mm Hg(1).
Literature: (1) Perry RH, Green D; Perry's Chemical Handbook. Physical and Chemical data. NY, NY: McGraw-Hill 6th ed (1984) (2) Yalkowsky SH, Dannenfelser RM; The AQUASOL dATAbASE of Aqueous Solubility. Fifth ed, Tucson, AZ: Univ Az, College of Pharmacy (1992) (3) Lyman WJ et al; Handbook of Chemical Property Estimation Methods. Washington, DC: Amer Chem Soc pp. 15-1 to 15-29 (1990)
Using a structure estimation method based on molecular connectivity indices(1), the Koc for ethyl propionate can be estimated to be about 12(SRC). According to a classification scheme(2), this estimated Koc value suggests that ethyl propionate is expected to have very high mobility in soil.
Literature: (1) Meylan WM et al; Environ Sci Technol 26: 1560-67 (1992) (2) Swann RL et al; Res Rev 85: 17-28 (1983)