Acetyl Acetone

CAS RN: 123-54-6

Environmental Fate

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 39(SRC), determined from a log Kow of 0.40(2) and a regression-derived equation(3), indicates that acetyl acetone is expected to have very high mobility in soil(SRC). Volatilization of acetyl acetone from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 2.3X10-6 atm-cu m/mole(SRC) derived from its vapor pressure, 2.96 mm Hg(4), and water solubility, 166,000 mg/L(5). Acetyl acetone is expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(4). In a screening study using settled sewage seed at 20 deg C, 5.6, 40.0, 62.8, and 69.6 % of theoretical BOD was determined after 5, 10, 15, and 20 incubation days, respectively(6). Although this study is not specific to soil media, it suggests that biodegradation in soil may be important(SRC).
AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 39(SRC), determined from a log Kow of 0.40(2) and a regression-derived equation(3), indicates that acetyl acetone is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(3) based upon an estimated Henry's Law constant of 2.3X10-6 atm-cu m/mole(SRC), derived from its vapor pressure, 2.96 mm Hg(4), and water solubility, 166,000 mg/L(5). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 16 days and 120 days, respectively(SRC). The aquatic oxidation rate for acetyl acetone has been experimentally determined to be 9.9X109 L/mol-s at pH 6.4(6). Based on this rate and a hydroxyl radical concn of 1X10-17 mol/L in water under continuous sunlight(7), the half-life for the aquatic oxidation of acetyl acetone can be estimated to be 81 days(SRC). According to a classification scheme(8), an estimated BCF of 3.2(SRC), from its log Kow(2) and a regression-derived equation(9), suggests the potential for bioconcentration in aquatic organisms is low(SRC). In a screening study using settled sewage seed at 20 deg C, 5.6, 40.0, 62.8, and 69.6 % of theoretical BOD was determined after 5, 10, 15, and 20 incubation days, respectively(10).
ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), acetyl acetone, which has a vapor pressure of 2.96 mm Hg at 20 deg C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase acetyl acetone 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 14 days(SRC), calculated from its rate constant of 1.15X10-12 cu cm/molecule-sec at 25 deg C(3).
Find more information on this substance at: PubChem, PubMed