1,2-Propanediol Dinitrate

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 68(SRC), determined from a structure estimation method(2), indicates that 1,2-propanediol dinitrate is expected to have high mobility in soil(SRC). Volatilization of 1,2-propanediol dinitrate from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 9.4X10-7 atm-cu m/mole(SRC), calculated using a fragment constant estimation method(3). 1,2-Propanediol dinitrate forms an azeotrope with water resulting in enhanced volatilization from water(4), but it is unclear whether this will be important in moist soils(SRC). 1,2-Propanediol dinitrate is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 0.38 mm Hg(SRC), determined from a fragment constant method(5). 1,2-Propanediol dinitrate was poorly biodegraded using an activated sewage sludge, a pure culture of Pseudomonas aeruginosa, and a commercially available inoculum employed for the degradation of nitrogen containing wastes(4), suggesting biodegradation in soil will be slow(SRC).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 68(SRC), determined from a structure estimation method(2), indicates that 1,2-propanediol dinitrate is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(3) based upon an estimated Henry's Law constant of 9.4X10-7 atm-cu m/mole(SRC), developed using a fragment constant estimation method(4); however, laboratory studies have shown that 1,2-propanediol dinitrate forms an azeotrope with water resulting in enhanced volatilization(5). The Henry's Law constant for the azeotrope was estimated to be about 1X10-2 atm-cu m/mole(5). Based on the Henry's Law constant for the azeotrope, the volatilization half-life from a model river and a model lake are estimated as 2 hours and 5 days, respectively(SRC). According to a classification scheme(6), an estimated BCF of 3(SRC), from an estimated log Kow of 1.59(7) and a regression-derived equation(8), suggests the potential for bioconcentration in aquatic organisms is low(SRC). 1,2-Propanediol dinitrate was poorly biodegraded using an activated sewage sludge, a pure culture of Pseudomonas aeruginosa, and a commercially available inoculum employed for the degradation of nitrogen containing wastes(5), suggesting biodegradation in water will be slow(SRC).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), 1,2-propanediol dinitrate, which has an estimated vapor pressure of 0.38 mm Hg at 25 deg C (SRC), determined from a fragment constant method(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase 1,2-Propanediol dinitrate is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 50 days(SRC), calculated from its rate constant of 3.2X10-13 cu cm/molecule-sec at 25 deg C(3).