O-Mustard

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 1180(SRC), determined from a structure estimation method(2), indicates that O-Mustard is expected to have low mobility in soil(SRC). Volatilization of O-Mustard from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 3.8X10-8 atm-cu m/mole(SRC), using a fragment constant estimation method(2). The Sulfur Mustards, including Agent T (O-Mustard), do not dissolve much in water(3), but the small quantity that dissolves is reactive(4). The hydrolysis half-life of dissolved O-Mustard was determined to be 2.8 minutes at 25 °C(5). O-Mustard is not expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 3X10-6 mm Hg at 25 °C(6). Biodegradation data in soil were not available(SRC, 2017).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 1180(SRC), determined from a structure estimation method(2), indicates that O-Mustard is 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 3.8X10-8 atm-cu m/mole(SRC), developed using a fragment constant estimation method(2). The Sulfur Mustards, including Agent T (O-Mustard), do not dissolve much in water(4), but the small quantity that dissolves is reactive(5). The hydrolysis half-life of dissolved O-Mustard was determined to be 2.8 minutes at 25 °C(6). According to a classification scheme(7), an estimated BCF of 28(SRC), from an estimated log Kow of 2.71(2) and a regression-derived equation(2), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Biodegradation data in water were not available(SRC, 2017).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), O-Mustard, which has a vapor pressure of 3X10-6 mm Hg at 25 °C(2), will exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase O-Mustard 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 5.2 hours(SRC), calculated from its rate constant of 7.5X10-11 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Particulate-phase O-Mustard may be removed from the air by wet and dry deposition(SRC).

IDENTIFICATION AND USE: O-Mustard is colorless when pure but is typically a yellow to brown oily substance with a slight garlic or mustard odor. This is a warfare and terrorism agent. HUMAN STUDIES: High doses of sulfur mustards can cause hyperexcitability, convulsions, and insomnia. The eye is the most sensitive tissue to sulfur mustard effects. Sulfur mustard vapor or liquid may cause intense conjunctival and scleral pain, swelling, lacrimation, blepharospasm, and photophobia; however, these effects do not appear for an hour or more. Miosis due to cholinergic effects may occur. High concentrations of vapor or liquid can cause corneal edema, perforation, blindness, and later scarring. Direct skin exposure to sulfur mustards causes erythema and blistering. Generally, a pruritic rash will develop within 4 to 8 hours followed by blistering 2 to 18 hours later. Contact with the vapor may result in first and second degree burns, while contact with the liquid typically produces second and third degree chemical burns. An area of burn covering 25% or more of the body surface area may be fatal. Ingestion may cause chemical burns of the GI tract and cholinergic stimulation. Nausea and vomiting may occur following ingestion or inhalation. Early nausea and vomiting is usually transient and not severe. Nausea, vomiting, and diarrhea occurring several days after exposure indicates damage to the GI tract and thus is a poor prognostic sign. Dose-dependent inflammatory reactions in the upper and lower airway begin to develop several hours after exposure and progress over several days. Burning nasal pain, epistaxis, sinus pain, laryngitis, loss of taste and smell, cough, wheezing, and dyspnea may occur. Necrosis of respiratory epithelium can cause pseudomembrane formation and local airway obstruction. Death usually occurs between 5 and 10 days due to pulmonary insufficiency complicated by infection due to immune system compromise. Systemic absorption of sulfur mustard may induce bone marrow suppression and an increased risk for fatal complicating infections, hemorrhage, and anemia. Years after apparent healing of severe eye lesions, relapsing keratitis or keratopathy may develop. Prolonged or repeated acute exposure to sulfur mustards may cause cutaneous sensitization and chronic respiratory disease. ANIMAL STUDIES: There are no data available.

Using a structure estimation method based on molecular connectivity indices(1), the Koc of O-Mustard can be estimated to be 1180(SRC). According to a classification scheme(2), this estimated Koc value suggests that O-Mustard is expected to have low mobility in soil.

/SIGNS AND SYMPTOMS/ Eyes are very susceptible to low concentrations; incapacitating effects by skin absorption require higher concentrations than does eye injury. /Mustard-T Mixture (HT)/

/SIGNS AND SYMPTOMS/ It is somewhat more vesicant than Levinstein mustard (H) on bare skin; however, it is less vesicant through wet or dry clothing and is somewhat less effective than H on the eyes. /Mustard-T Mixture (HT)/

/SIGNS AND SYMPTOMS/ Death usually occurs between the 5 and 10 day due to pulmonary insufficiency complicated by infection due to immune system compromise. /Sulfur mustards/

/SIGNS AND SYMPTOMS/ The eye is the most sensitive tissue to sulfur mustard effects. Sulfur mustard vapor or liquid may cause intense conjunctival and scleral pain, swelling, lacrimation, blepharospasm, and photophobia; however, these effects do not appear for an hour or more. Miosis due to cholinergic effects may occur. High concentrations of vapor or liquid can cause corneal edema, perforation, blindness, and later scarring. /Sulfur mustards/

For more Human Toxicity Excerpts (Complete) data for O-Mustard (16 total), please visit the HSDB record page.

O-Mustard's limited production for research may result in its release to the environment through various waste streams; its illegal use as a chemical warfare agent(1,2) will result in its direct release to the environment(SRC). Destruction of US stockpiles of chemical agents, including sulfur mustards, was mandated by the Chemical Weapons Convention to take place before April 2007(2).

In August 1988, chemical weapons were reported used against Kurdish populations in the mountainous region of northern Iraq close to the borders of Turkey and Iran(1). In November of that year, soil samples (and other samples) were collected from a hillside site of an impacted bomb(1). Analysis of the soil samples identified degradation products of sulfur mustard and O-mustard(1).

An estimated BCF of 28 was calculated in fish for O-Mustard(SRC), using an estimated log Kow of 2.71(1) and a regression-derived equation(1). According to a classification scheme(2), this BCF suggests the potential for bioconcentration in aquatic organisms is low(SRC).

The Henry's Law constant for O-Mustard is estimated as 3.8X10-8 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that O-Mustard is expected to be essentially nonvolatile from water surfaces(2). In addition, any O-Mustard that dissolves into water will be reactive with the water(3). O-Mustard's Henry's Law constant indicates that volatilization from moist soil surfaces is not expected to occur(SRC). O-Mustard is not expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 3X10-6 mm Hg at 25 °C(4).

The rate constant for the vapor-phase reaction of O-Mustard with photochemically-produced hydroxyl radicals has been estimated as 7.5X10-11 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 5.2 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). The apparent hydrolysis half-life of O-Mustard at 25 °C was determined to be 2.8 minutes in an aqueous solution containing 5% ethanol at pH of 5-8(1).

O-Mustard's limited production for research may result in its release to the environment through various waste streams; its illegal use as a chemical warfare agent will result in its direct release to the environment. Destruction of US stockpiles of chemical agents, including sulfur mustards, was mandated by the Chemical Weapons Convention to take place before April 2007. If released to air, a vapor pressure of 3X10-6 mm Hg at 25 °C indicates O-Mustard will exist in both the vapor and particulate phases in the atmosphere. Vapor-phase O-Mustard 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 5.2 hours. Particulate-phase O-Mustard will be removed from the atmosphere by wet and dry deposition. If released to soil, O-Mustard is expected to have low mobility based upon an estimated Koc of 1180. Volatilization from moist soil surfaces is not expected to be an important fate process based upon an estimated Henry's Law constant of 3.8X10-8 atm-cu m/mole. O-Mustard is not expected to volatilize from dry soil surfaces based upon its vapor pressure. O-Mustard does not dissolve much in water, but the quantity that dissolves is reactive indicating that hydrolysis in moist soil is an important fate process. Biodegradation data in soil or water were not available. If released into water, O-Mustard is expected to adsorb to suspended solids and sediment based upon the estimated Koc. Volatilization from water surfaces is not expected to be an important fate process based upon this compound's estimated Henry's Law constant. O-Mustard that dissolves in water has a hydrolysis half-life of 2.8 minutes at 25 °C. Occupational exposure to O-Mustard may occur through inhalation and dermal contact with this compound at workplaces where O-Mustard is produced or used. (SRC)

O-Mustard (T)

CUM 100g

CUM 100g

Chemical Weapons/Chemical Weapons Precursors chemical material that, if stolen or diverted, can be converted into weapons using simple chemistry, equipment, or techniques.