Diethyl Adipate

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 45(SRC), determined from a water solubility of 4,230 mg/l at 20 °C(2) and a regression-derived equation(3), indicates that diethyl adipate is expected to have very high mobility in soil(SRC). Volatilization of diethyl adipate from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 3.6X10-6 atm-cu m/mole(SRC), from a vapor pressure of 0.058 mm Hg(4) and its water solubility(2). Volatilization from dry soil surfaces is not expected to be an important environmental fate process based on the vapor pressure(4). Diethyl adipate was degraded to adipic acid using an activated sludge inoculum(5), suggesting biodegradation may be an important fate process in soils(SRC).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 45(SRC), determined from a water solubility of 4,230 mg/l at 20 °C(2) and a regression-derived equation(3), indicates that diethyl adipate is not expected to adsorb to suspended solids and sediment in water(SRC). Volatilization from water surfaces is expected(3) based upon an estimated Henry's Law constant of 3.6X10-6 atm-cu m/mole(SRC), from a vapor pressure of 0.058 mm Hg(4) and its water solubility(2). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 10 and 110 days, respectively(SRC). A base-catalyzed second-order hydrolysis rate constant of 0.12 L/mole-sec(SRC) was estimated using a structure estimation method(5); this corresponds to half-lives of 1.7 years and 64 days at pH values of 7 and 8, respectively(5). Diethyl adipate was degraded to adipic acid using an activated sludge inoculum(6), suggesting biodegradation may be an important fate process in water(SRC). According to a classification scheme(7), an estimated BCF of 6(SRC), from its water solubility and a regression-derived equation(3), suggests the potential for bioconcentration in aquatic organisms is low(SRC).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), diethyl adipate, which has a vapor pressure of 0.058 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase diethyl adipate 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 2 days(SRC), calculated from its estimated rate constant of 7.8X10-12 cu cm/molecule-sec at 25 °C(SRC) determined using a structure estimation method(3). Diethyl adipate may also undergo direct photolysis in the environment since this compound contains functional groups that can absorb light greater than 290 nm(4).

The Koc of diethyl adipate is estimated as 45(SRC), using a water solubility of 4,230 mg/l(1) and a regression-derived equation(2). According to a classification scheme(3), this estimated Koc value suggests that diethyl adipate is expected to have very high mobility in soil(SRC).

An estimated BCF of 6 was calculated for diethyl adipate(SRC), using a water solubility of 4,230(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is low(SRC).

The Henry's Law constant for diethyl adipate is estimated as 3.6X10-6 atm-cu m/mole(SRC) from its vapor pressure, 0.058 mm Hg(1), and water solubility, 4,230 mg/l(2). This Henry's Law constant indicates that diethyl adipate 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 10 days(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 110 days(SRC). Diethyl adipate's estimated Henry's Law constant(1,2) indicates that volatilization from moist soil surfaces may occur(SRC). Volatilization from dry soil surfaces is not expected to be an important environmental fate process for diethyl adipate(SRC) based on its vapor pressure(1).

DERMAL IRRITATION SLIGHT. /FROM TABLE/

SINGLE IP DOSES OF DIETHYL ADIPATE GIVEN TO MALE MICE MATED WITH UNTREATED VIRGIN FEMALES PRODUCED DOSE-DEPENDENT ANTIFERTILITY & DOMINANT LETHAL MUTAGENIC EFFECTS, AS INDICATED BY REDUCED PERCENTAGE OF PREGNANCIES & INCR NUMBER OF EARLY FETAL DEATHS. MUTATIONAL EFFECTS OCCURRED MAINLY DURING POSTMEIOTIC STAGE OF SPERMATOGENESIS.

SEVEN ADIPATES INCL DIETHYL ADIPATE WERE EVALUATED FOR THEIR EMBRYONIC-FETAL TOXICITY & TERATOGENIC EFFECTS IN RATS. THE ADIPATES APPEAR TO BE LESS TERATOGENIC THAN PHTHALATES WHEN ADMIN DURING GESTATION IN EQUIVALENT FRACTIONS OF RESPECTIVE LD50 DOSES.

Alkyloxy adipates are slightly more toxic than the parent hydrocarbon esters. ... It is possible that the ether linkage increases its toxicity toward the hepatic system, or ethylene glycol may be formed metabolically, which might affect the renal and, to a lesser extent, the hepatic system. /Alkyloxy adipates/

Moderately toxic by intraperitoneal route. Experimental reproductive effects. Mutation data reported.

The rate constant for the vapor-phase reaction of diethyl adipate with photochemically-produced hydroxyl radicals has been estimated as 7.8X10-12 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 2 days at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). A base-catalyzed second-order hydrolysis rate constant of 0.12 L/mole-sec(SRC) was estimated using a structure estimation method(2); this corresponds to half-lives of 1.7 years and 64 days at pH values of 7 and 8, respectively(2). Diethyl adipate may also undergo direct photolysis in the environment since this compound contains functional groups that can absorb light greater than 290 nm(3).

Diethyl adipate's production and use as a plasticizer may result in its release to the environment through various waste streams. If released to air, a vapor pressure of 0.058 mm Hg at 25 °C indicates diethyl adipate will exist solely as a vapor in the ambient atmosphere. Vapor-phase diethyl adipate will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals; the half-life for this reaction in air is estimated to be 2 days. Diethyl adipate may undergo direct photolysis in the environment, but the kinetics of this reaction are unknown. If released to soil, diethyl adipate is expected to have very high mobility based upon an estimated Koc of 45. Volatilization from moist soil surfaces is expected to be an important fate process based upon an estimated Henry's Law constant of 3.6X10-6 atm-cu m/mole. Volatilization from dry soil surfaces is not expected to be an important environmental fate process based on the vapor pressure of this compound. Diethyl adipate was degraded to adipic acid using an activated sludge inoculum in a single screening study. If released into water, diethyl adipate is not expected to adsorb to suspended solids and sediment in water based upon the estimated Koc. Volatilization from water surfaces is expected to be an important fate process based upon this compound's estimated Henry's Law constant. Estimated volatilization half-lives for a model river and model lake are 10 and 110 days, respectively. Hydrolysis may be an important environmental fate process based on estimated hydrolysis half-lives of 64 days and 1.7 years at pH 8 and 7, respectively. An estimated BCF of 6 suggests the potential for bioconcentration in aquatic organisms is low. Occupational exposure to diethyl adipate may occur through inhalation and dermal contact with this compound at workplaces where diethyl adipate is produced or used. (SRC)