1,2-Ethanedithiol

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 44(SRC), determined from a structure estimation method(2), indicates that 1,2-ethanedithiol is expected to have very high mobility in soil(SRC). Volatilization of 1,2-ethanedithiol from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 1.2X10-4 atm-cu m/mole(SRC), using a fragment constant estimation method(3). 1,2-Ethanedithiol is expected to volatilize from dry soil surfaces(SRC) based upon an extrapolated vapor pressure of 5.61 mm Hg(4). Biodegradation data were not available(SRC, 2005).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 44(SRC), determined from a structure estimation method(2), indicates that 1,2-ethanedithiol 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 1.2X10-4 atm-cu m/mole(SRC), developed using a fragment constant estimation method(4). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 3 days and 17 days, respectively(SRC). According to a classification scheme(5), an estimated BCF of 2(SRC), from an estimated log Kow of 1.2(6) and a regression-derived equation(7), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Biodegradation data were not available(SRC, 2005).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), 1,2-ethanedithiol, which has an extrapolated vapor pressure of 5.61 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase 1,2-ethanedithiol 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 5 hours(SRC), calculated from its rate constant of 8.3X10-11 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). 1,2-Ethanedithiol does not contain chromophores that absorb at wavelengths >290 nm and therefore is not expected to be susceptible to direct photolysis by sunlight(SRC).

/AQUATIC SPECIES/ Static aquatic assays were conducted for 24 hr on three species of fish. No mortality or change in equilibrium resulted from 5 ppm in Northern squawfish, and 10 ppm caused the death of Coho salmon, steelhead trout, and Northern squawfish in 2 to 14 hr (high alkalinity and hardness). In different water conditions (low alkalinity and hardness), mortality was observed in Northern squawfish at 10 ppm in 7 to 19 hr.

Using a structure estimation method based on molecular connectivity indices(1), the Koc of 1,2-ethanedithiol can be estimated to be 44(SRC). According to a classification scheme(2), this estimated Koc value suggests that 1,2-ethanedithiol is expected to have very high mobility in soil.

The ability of 1,2-ethanedithiol to induce specific locus mutations at the TK locus in cultured L5178Y mouse lymphoma cells (Mouse Lymphoma Mutagenicity Assay) was evaluated in the presence and absence of Aroclor-induced rat liver S9 metabolic activation. Based on preliminary toxicity determinations, nonactivated cultures were treated with concentrations ranging from 13ug/mL to 150ug/mL, producing a range of 32.5 - 0.9% total survival. S9 activated cultures treated with concentrations ranging from 0.07ug/mL to 1ug/mL produced a range of 48.9 - 3% total survival. Nonactivated cultures exhibited a dose-related increase in the mutant frequency relative to the solvent control (DMSO). No increase in forward mutations was observed in the presence of metabolic activation.

The mutagenicity of 1,2-ethanedithiol was evaluated in Salmonella tester strains TA98, TA100, TA1535, TA1537 and TA1538 (Ames Test), both in the presence and absence of added metabolic activation by Aroclor-induced rat liver S9 fraction. Based on preliminary toxicity determinations, 1,2-ethanedithiol, diluted in DMSO, was tested at concentrations up to 5,000ug/plate using the plate incorporation technique. 1,2-Ethanedithiol did not cause a positive response in any tester strain with or without metabolic activation.

The ability of 1,2-ethanedithiol to induce Sister Chromatid Exchange (SCE) in Chinese hamster ovary (CHO) cells was evaluated both in the presence and absence of Aroclor-induced rat liver S9 metabolic activation. Based on preliminary toxicity tests, 1,2-ethanedithiol diluted with DMSO, was tested at concentrations of 0, 0.5, 1.6, 5.0, 16 or 50 ug/mL. In nonactivated cultures, concentrations of 16 and 50 ug/mL (p < 0.0001) and in activated cultures, concentrations of 1.6 and 5.0 ug/mL (p = 0.004), 16 ug/mL (p = 0.002), and 50 ug/mL (p < 0.0001) induced statistically significant increases in the frequency of SCE relative to controls.

/SIGNS AND SYMPTOMS/ Vapors of ethanedithiol may cause severe headache and nausea.

/CASE REPORTS/ ... A 22-year-old female chemistry student who developed widespread erythema multiforme-like lesions after local contact with 1,2-ethanedithiol. Many target lesions were observed bilaterally on her hands, forearms, arms, and on her forehead. One such lesion was histologically compatible with erythema multiforme. The patient had a positive patch test to 1,2-ethanedithiol, whereas none of 30 healthy subjects showed a positive reaction. However, eight of the 30 controls (26.7%) developed irritant reactions to 1,2-ethanedithiol.

An estimated BCF of 2 was calculated for 1,2-ethanedithiol(SRC), using an estimated log Kow of 1.21(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 1,2-ethanedithiol is estimated as 1.2X10-4 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that 1,2-ethanedithiol 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 2 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)(2) is estimated as 17 days(SRC). 1,2-Ethanedithiol is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 5.61 mm Hg(3).

/LABORATORY ANIMALS: Acute Exposure/ In general /in rats/, toxicological signs noted after oral dosing included decreased activity, depression, ataxia, labored respiration, loss of righting reflex, tremors, and convulsions.

/LABORATORY ANIMALS: Acute Exposure/ Toxicological signs /in rabbits dermally exposed/ included depression, weakness, labored respiration, tremors, erythema, edema, and sloughing of the skin at the application site.

/LABORATORY ANIMALS: Acute Exposure/ A /sensory/ irritation study of mice found depressions in the respiratory rates at 87 ppm (1 minute intervals).

/LABORATORY ANIMALS: Acute Exposure/ ...Clinical signs /in mice exposed by inhalation/ included lack of muscular coordination, lacrimation, ataxia, labored respiration, and progressive cyanosis.

For more Non-Human Toxicity Excerpts (Complete) data for 1,2-ETHANEDITHIOL (7 total), please visit the HSDB record page.

The rate constant for the vapor-phase reaction of 1,2-ethanedithiol with photochemically-produced hydroxyl radicals has been estimated as 8.3X10-11 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 5 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). 1,2-Ethanedithiol is not expected to undergo hydrolysis in the environment due to the lack of hydrolyzable functional groups(2). 1,2-Ethanedithiol does not contain chromophores that absorb at wavelengths >290 nm and therefore is not expected to be susceptible to direct photolysis by sunlight(SRC).