Mustard gas

Description

Mustard gas/sulphur mustard is an organic chemical substance synthesised by treating sulphur dichloride with ethylene. Mustard gas is a chemical substance closely related to chemical warfare class agents. It is a cytotoxic and vesicant chemical substance, and exposures are known to cause blisters on the exposed skin. Pure mustard gas/sulphur mustards are colourless, viscous liquids at room temperature. However, when used in impure form, such as warfare agents, they appear as yellow brown in colour. As the name indicates, mustard gas has an odour resembling the garlic, horseradish, or mustard plants. Mustard gas is the common name given to 1,1-thiobis(2-chloroethane), a chemical warfare agent that is believed to have first been used near Ypres in Flanders on 12 July 1917. Mustard gas is a thick liquid at ambient temperature. It is heavier than water as a liquid and heavier than air as a vapour. It does not occur naturally in the environment. Pure liquid mustard gas is colourless and odourless. It is stable, combustible, and incompatible with strong oxidising agents. Mustard gas on mixing with other chemical substances appears brown in colour and gives off a garlic-like smell. When heated, it decomposes and emits highly toxic, corrosive fumes and fumes of oxides of sulphur and chlorine-containing compounds. It is soluble in fats and oils, gasoline, kerosene, acetone, carbon tetrachloride, alcohol, tetrachloroethane, ethylbenzoate, and ether, and solubility in water is negligible. It is miscible with the OP nerve agents. During earlier years, mustard gas was in use as an important chemical warfare agent. In fact, it was used in large amounts during World Wars I and II. Mustard gas was first used by the German army in 1917. It was one of the most lethal of all the poisonous chemicals used during the war. It was reportedly used in the Iran–Iraq war in 1980–1988. It is not presently used in the United States, except for research purposes.

Description

VX (a thiophosphonate ester) and sulfur mustard [bis(2-chloroethyl) sulfide] are chemical warfare agents. VX, first patented in 1974, is an acetylcholinesterase inhibitor that is more potent than?sarin. Sulfur mustard, also known as mustard gas, is a vesicant whose effects include skin blisters, edema, and conjunctivitis; it was prepared as early as 1822. Chemists are currently developing methods to?detect trace amounts of these and other chemical weapons.

Chemical properties

Mustard gas, a chlorinated sulfur compound(s), is an oily, yellow to black liquid (clear when pure). It has a sweet, burnt garlic or horseradish-like odor. The odor threshold for HD is 0.0006 milligram per cubic meter.

The Uses of Mustard gas

Formerly in chemical warfare. In biological studies of alkylating agents.

The Uses of Mustard gas

As a vesicant in chemical warfare. Although US stockpiles were thought to exist only through the early 1970s, several other countries currently maintain large stockpiles that present an imminent danger from accidental or intentional exposure.1 Also used in small quantities as a model compound in biological studies on alkylating agents.

The Uses of Mustard gas

Sulfur mustard (SM) is a chemical warfare agent belonging to the blister agent/vesicant class. It is a cytotoxic and alkylating compound similar to other types of vesicants or blister agents such as nitrogen mustard, lewisite, and phosgene oxide. SM was used on a large scale during World War I and in the Iraq– Iran conflict in 1983–1988. It was also used by Italian troops in Ethiopia (1935–1936) and by Egyptian forces in Yemen (1963–1967). Most of the Iranian patients are still suffering from the delayed toxic effects and complications of SM poisoning.

Definition

ChEBI: An ethyl sulfide that is diethyl sulfide in which a hydrogen from each of the terminal methyl groups is replaced by a chlorine. It is a powerful vesicant regulated under the Chemical Weapons Convention.

General Description

Mustard gas is a clear amber colored oily liquid with a faint odor of mustard/garlic. Mustard gas is not readily combustible. Its vapors are heavier than air, are very toxic, and can be absorbed through the skin. The effects from exposure to the material include blindness which may be delayed. Prolonged exposure of the container to fire or intense heat may cause Mustard gas to violently rupture and rocket. Mustard gas is also known as dichlorodiethyl sulfide.

Air & Water Reactions

Reacts with water or steam to produce toxic and corrosive fumes(oxides of sulfur and chlorine)

Reactivity Profile

Mustard gas is incompatible with bleaching powder. Reacts violently with oxidizing materials. Reacts with water or steam to produce toxic and corrosive fumes. Unstable, hydrolyzed in aqueous solution. Avoid high heat; contact with acid or acid fumes. [EPA, 1998].

Health Hazard

The median lethal dosage is 1500 mg-minute/m3 for inhalation and 10,000 mg-minute/m3 for skin absorption (masked personnel). The median incapacitating dosage is 200 mg-minute/m3 for eye injury and 2000 mg-minute/m3 for skin absorption (masked personnel). Wet skin absorbs more material than dry skin. May cause death or permanent injury after very short exposure to small quantities. It is a blistering gas and is highly irritating to eyes, skin, and lungs. Pulmonary lesions are often fatal. Permanent eye damage and severe respiratory impairment. It is a carcinogen.

Fire Hazard

Can be ignited by large explosive charge. When heated to decomposition, emits highly toxic fumes of oxides of sulfur and chlorine containing compounds. Reacts with water or steam to produce toxic and corrosive fumes. Containers may rupture violently in a fire. Incompatible with bleaching powder. Reacts violently with oxidizing materials. Reacts with water or steam to produce toxic and corrosive fumes. Unstable, hydrolyzed in aqueous solution. Avoid high heat; contact with acid or acid fumes.

Safety Profile

Confirmed human carcinogenwith experimental carcinogenic, neoplastigenic, andtumorigenic data. A human poison by inhalation andsubcutaneous routes. An experimental poison byinhalation, skin contact, subcutaneous, and intravenousroutes. An experimenta

Potential Exposure

Mustard gas is used as an alkylating agent. It has also been used as a chemical warfare agent, causing delayed casualties. It is a vesicant and blister agent in chemical warfare (especially during World War I, military designation H or HD). Mustard gas is used as a model compound in biological studies. Mustard gas has been tested as an antineoplastic agent, but its clinical use as a tumor inhibitor has been minimal.

First aid

There is no antidote for sulfur mustard toxicity.If this chemical gets into the eyes instantly flush with water.A delay of seconds can cause permanent damage.Inhalation: Remove from the source immediately. If breathing has stopped, give artificial respiration. If breathing isdifficult, administer oxygen. Seek medical attention immediately. Eye contact: Speed in decontaminating the eyes isabsolutely essential. Remove person from the liquid source;flush the eyes immediately with water by tilting the head tothe side, pulling the eyelids apart with the fingers, and pouring water slowly into the eyes. Do not cover eyes with bandages but, if necessary, protect eyes by means of dark oropaque goggles. Transfer the patient to a medical facilityimmediately. Ingestion: Do not induce vomiting. Give victim milk to drink. Seek medical attention immediately. Skincontact: Don respiratory protective mask and gloves;remove victim from agent source immediately. Flush skinand clothes with solution of sodium hypochlorite or liquidhousehold bleach (see decontamination procedure below)within 1 min. Cut and remove contaminated clothing, flushcontaminated skin area again with sodium hypochloritesolution, then wash contaminated skin area with soap andwater. If shower facilities are available, wash thoroughlyand transfer to medical facility. If the skin becomes contaminated with a thickened agent, blot/wipe off the materialimmediately with an absorbent pad/paper towel prior tousing decontaminating solution.

Carcinogenicity

Mustard gas is known to be a human carcinogen based on sufficient evidence of carcinogenicity from studies in humans.

storage

Protective gloves, mandatory: Butyl, toxicological agent, protective gloves (M3, M4,glove set). As a minimum, chemical goggles will be worn.For splash hazards use goggles and face shield. Full protective clothing will consist of the M3 butyl rubber suit withhood, M2A1 butyl boots; M3 gloves; impregnated underwear; M9 series mask and coveralls (if desired); or theDemilitarization Protective Ensemble (DPE). For generallab work, gloves and lab coat shall be worn with M9 orM17 mask readily available. In addition, when handlingcontaminated lab animals, a daily clean smock, foot covers,and head covers are required. Ventilation: Local Exhaust:Mandatory. Must be filtered or scrubbed. Special: Chemicallaboratory hoods shall have an average inward face velocityof 100 linear feet per minute (lfpm) plus or minus 10% withthe velocity at any point not deviating from the averageface velocity by more than 20%. Laboratory hoods shall belocated so that cross-drafts do not exceed 20% of the inwardface velocity. A visual performance test utilizing smokeproducing devices shall be performed in assessing the ability of the hood to contain agent HD. Other: recirculation ofexhaust air from agent areas is prohibited. No connectionbetween agent areas and other areas through ventilation system is permitted. Emergency backup power is necessary.Hoods should be tested semi-annually or after modificationor maintenance operations. Operations should be performedwith 20 cm inside hoods

Shipping

UN2810 Toxic liquids, organic, n.o.s., Hazard Class: 6.1; Labels: 6.1-Poisonous materials, Technical Name Required.

Toxicity evaluation

Although SM reacts with RNA, proteins, and phospholipids, the consensus view is that a DNA alkylate plays an important role in delayed toxic effects. This DNA alkylation and crosslinking in rapidly dividing cells such as basal keratinocytes, mucosal epithelium, and bone marrow precursor cells leads to cellular death and inflammatory reactions. At higher levels of cellular exposure, however, mechanisms other than DNA crosslinking that produce more rapid cell death may become important. The acute damage to the cornea, mucous membranes, and skin seen after SM exposure is probably generated by one or both of these two mechanisms: (1) depletion of nicotinamide adenine dinucleotide (NAD); (2) rapid inactivation of sulfhydryl-containing proteins and peptides, such as glutathione.

Incompatibilities

Sulfur mustard is stable at ambient temperatures. Reacts with oxidizers (vigorous), strong acids; acid fumes; strong alkalies; oxygen; water, steam, and other forms of moisture. On contact with acid or acid fumes, it emits highly toxic fumes of oxides of sulfur and chlorine. Rapidly corrosive to brass @ 65℃. Will corrode steel at a rate of 0.0001 in/month @ 65℃. HD reacts with water; will hydrolyze; forming HCI and thiodiglycol. When heated to decomposition (between 149℃ to 177℃), it emits gaseous hydrogen chloride and oxides of sulfur and chlorine. Contact with metals may evolve flammable hydrogen gas.

Waste Disposal

Principles and methods for destruction of chemical weapons: “Destruction of chemical weapons” means a process by which chemicals are converted in an essentially irreversible way to a form unsuitable for production of chemical weapons, and which in an irreversible manner renders munitions and other devices unusable as such. Each nation shall determine how it shall destroy chemical weapons, except that the following processes may not be used: dumping in any body of water, land burial or open-pit burning. It shall destroy chemical weapons only at specifically designated and appropriately designed and equipped facilities. Each nation shall ensure that its chemical weapons destruction facilities are constructed and operated in a manner to ensure the destruction of the chemical weapons; and that the destruction process can be verified under the provisions of this Convention . All decontaminated material should be collected, contained and chemically decontaminated or thermally decomposed in an EPA approved incinerator, which will filter or scrub toxic by-products from effluent air before discharge to the atmosphere. Any contaminated protective clothing should be decontaminated using calcium hypochlorite (HTH) or bleach and analyzed to assure it is free of detectable contamination (3X) level. Contaminated clothes and personal belongings should be placed in a sealed double bag and subsequently placed inside properly labeled drums and held for shipment back to the DA issue point. Decontamination of waste or excess material shall be accomplished in accordance with the procedures outlined above with the following exceptions: (a) HD on laboratory glassware may be oxidized by its vigorous reaction with concentrated nitric acid. (b) Open pit burning or burying of HD or items containing or contaminated with HD in any quantity is prohibited. Note: Several states define decontaminated surety material as a RCRA Hazardous Waste.