The Henry's Law constant for iodoform is estimated as 3.1 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that iodoform is expected to volatilize from water surfaces(2). 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)(2) is estimated as 40 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)(2) is estimated as 25 days(SRC). Iodoform's Henry's Law constant(1) indicates that volatilization from moist soil surfaces may occur(SRC). Iodoform is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 0.040 mm Hg(SRC), determined from a fragment constant method(3).
Literature: (1) Meylan WM, Howard PH; Environ Toxicol Chem 10: 1283-93 (1991) (2) Lyman WJ et al; Handbook of Chemical Property Estimation Methods. Washington, DC: Amer Chem Soc pp. 15-1 to 15-29 (1990) (3) Lyman WJ; p 31 in Environmental Exposure From Chemicals Vol I, Neely WB, Blau GE(eds), Boca Raton, FL: CRC Press (1985)
Using a structure estimation method based on molecular connectivity indices(1), the Koc for iodoform can be estimated to be 35(SRC). According to a classification scheme(2), this estimated Koc value suggests that iodoform 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)