Sesquimustard

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 1450(SRC), determined from a structure estimation method(2), indicates that sesquimustard is expected to have low mobility in soil(SRC). Volatilization of sesquimustard from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 4.7X10-9 atm-cu m/mole(SRC), developed using a fragment constant estimation method(2). The Sulfur Mustards do not dissolve much in water(3), but the small quantity that dissolves is reactive(4). The hydrolysis half-life of dissolved sesquimustard was determined to be 1.7 minutes at 25 °C(5). Sesquimustard is not expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 3.5X10-6 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 1450(SRC), determined from a structure estimation method(2), indicates that sesquimustard 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 4.7X10-9 atm-cu m/mole(SRC), developed using a fragment constant estimation method(2). The Sulfur Mustards do not dissolve much in water(4), but the small quantity that dissolves is reactive(5). The hydrolysis half-life of dissolved sesquimustard was determined to be 1.7 minutes at 25 °C(6). According to a classification scheme(7), an estimated BCF of 43(SRC), from an estimated log Kow of 2.99(2) and a regression-derived equation(2), suggests the potential for bioconcentration in aquatic organisms is moderate(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), sesquimustard, which has a vapor pressure of 3.5X10-6 mm Hg at 25 °C(2), will exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase sesquimustard 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 hours(SRC), calculated from its rate constant of 2.7X10-11 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Particulate-phase sesquimustard may be removed from the air by wet and dry deposition(SRC).

IDENTIFICATION AND USE: Sesquimustard (Q) is a vesicant/blister agent more potent than distilled mustard (HD). It is combined with HD to form agent HQ. It could also be formed in small amounts during storage of HD in ton containers. HUMAN STUDIES: Vesicants, also referred to as "blister agents," were the most commonly used chemical warfare agents during World War I. The most likely routes of exposure are inhalation, dermal contact, and ocular contact. Vesicants are highly reactive chemicals that combine with proteins, DNA, and other cellular components to result in cellular changes immediately after exposure. Clinical effects may be delayed for 2 to 24 hours. Following exposure, the most commonly encountered clinical effects include dermal (skin erythema and blistering), respiratory (pharyngitis, cough, dyspnea), ocular (conjunctivitis and burns), and gastrointestinal (nausea and vomiting). The amount and route of exposure to the vesicant, the type of vesicant, and the premorbid condition of the person exposed will contribute to the time of onset and the severity of illness. For example, ingestion of a vesicant leads to gastrointestinal symptoms more prominent than those that would result from inhalation exposure to the same dose and type of vesicant. ANIMAL STUDIES: Acute inhalation toxicity studies with sesquimustard have been made in mice, rats, guinea pigs, hamsters, pigeons, and dogs. Following exposure, animals show loss of body weight, coughing, dyspnea, ataxia, and diarrhea prior to death. Deaths occurred over a 14-day observation period with a primary peak between the third and sixth day. Tissue damage in most animals was limited to the upper respiratory tract and digestive tract.

Using a structure estimation method based on molecular connectivity indices(1), the Koc of sesquimustard can be estimated to be 1450(SRC). According to a classification scheme(2), this estimated Koc value suggests that sesquimustard is expected to have low mobility in soil(SRC).

/SIGNS AND SYMPTOMS/ Vesicants, also referred to as "blister agents," were the most commonly used chemical warfare agents during World War I. The most likely routes of exposure are inhalation, dermal contact, and ocular contact. Vesicants are highly reactive chemicals that combine with proteins, DNA, and other cellular components to result in cellular changes immediately after exposure. Depending on the vesicant, clinical effects may occur immediately (as with phosgene oxime or lewisite) or may be delayed for 2 to 24 hours (as with mustards). Following exposure, the most commonly encountered clinical effects include dermal (skin erythema and blistering), respiratory (pharyngitis, cough, dyspnea), ocular (conjunctivitis and burns), and gastrointestinal (nausea and vomiting). The amount and route of exposure to the vesicant, the type of vesicant, and the premorbid condition of the person exposed will contribute to the time of onset and the severity of illness. For example, ingestion of a vesicant leads to gastrointestinal symptoms more prominent than those that would result from inhalation exposure to the same dose and type of vesicant. /Vesicants/

/SIGNS AND SYMPTOMS/ Respiratory signs and symptoms: chest tightness, clear rhinorrhea, cough Dyspnea (shortness of breath), hemoptysis, nasal irritation/pain, sore throat, tachypnea. /Vesicants/

/SIGNS AND SYMPTOMS/ Dermal signs and symptoms: blisters (within 1 hour with phosgene oxime, delayed for 2 to 12 hours with lewisite, delayed for 2 to 24 hours with mustards); erythema (immediate with lewisite and phosgene oxime, may be delayed for 2 to 24 hours with mustards); immediate blanching (phosgene oxime); itching; necrosis and eschar (over a period of 7 to 10 days). /Vesicants/

/SIGNS AND SYMPTOMS/ Ocular signs and symptoms: blindness, blurred vision, corneal ulceration, conjunctivitis, eyelid edema, eye pain/burning, lacrimation, photophobia. /Vesicants/

For more Human Toxicity Excerpts (Complete) data for Sesquimustard (10 total), please visit the HSDB record page.

Sesquimustard's production may result in its release to the environment through various waste streams; its use as a chemical warfare agent(1) 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).

SOIL: 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 sesquimustard(1).

An estimated BCF of 43 was calculated in fish for sesquimustard(SRC), using an estimated log Kow of 2.99(1) and a regression-derived equation(1). According to a classification scheme(2), this BCF suggests the potential for bioconcentration in aquatic organisms is moderate(SRC).

The Henry's Law constant for sesquimustard is estimated as 4.7X10-9 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that sesquimustard is expected to be essentially nonvolatile from water surfaces(2). In addition, any sesquimustard that dissolves into water will be reactive with the water(3). Sesquimustard's Henry's Law constant indicates that volatilization from moist soil surfaces is not expected to occur(SRC). Sesquimustard is not expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 3.5X10-6 mm Hg at 25 °C(4).

/LABORATORY ANIMALS: Acute Exposure/ Acute inhalation toxicity studies with 1,2-bis(2-chloroethylthio)ethane have been made in mice, rats, guinea pigs, hamsters, pigeons, and dogs. Following exposure, animals show loss of body weight, coughing, dyspnea, ataxia, and diarrhea prior to death. Deaths occurred over a 14-day observation period with a primary peak between the third and sixth day. Pigeons were the least sensitive of the species tested. Tissue damage in most animals was limited to the upper respiratory tract and digestive tract.

The rate constant for the vapor-phase reaction of sesquimustard with photochemically-produced hydroxyl radicals has been estimated as 2.7X10-11 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 14 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). The apparent hydrolysis half-life of sesquimustard at 28 °C was determined to be 8.1 minutes in an aqueous solution containing 32% dioxane(1); the hydrolysis half-life extrapolated to pure water at 25 °C is 1.7 minutes(2).

Sesquimustard decontamination derivatives were detected in decontamination waste from chemical weapons (CW) agents stored in containers on Johnston Atoll (US territory located in the Pacific Ocean) since 1971(1). Sesquimustard occurs as an impurity in sulfur mustard used as a chemical warfare agent(2).

Sesquimustard

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.