1,1-Difluoroethene

CAS RN:75-38-7

Volatilization

The Henry's Law constant for 1,1-difluoroethene is estimated as 0.4 atm-cu m/mole(SRC) derived from its vapor pressure, 3X10+4 mm Hg(1), and water solubility, 169 mg/L(2). This Henry's Law constant indicates that 1,1-difluoroethene is expected to volatilize rapidly 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 2.3 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 3.2 days(SRC). 1,1-Difluoroethene's estimated Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC). The potential for volatilization of 1,1-difluoroethene from dry soil surfaces may exist(SRC) based upon its vapor pressure(1).
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