Table 2.

Physical properties of sulfur mustard

Properties	Description	References
Formulation	C4H8Cl2S	[1,18]
	2 side chains of dichloroethyl/sulfide or bis (2-chloro-ethyl) sulfide
Color	Colorless, lucent, or pale yellow (pure) to yellow, brown, dark brown or black color (impure).	[8,18]
Odor	Sulfur mustard has a slight garlic, horseradish, addled egg or fried vegetables or mustard type odor.	[8,14,18]
Form	Oily substance, liquid (in room temperature), solid, powder (decontamination is much more difficult), gas or vapor. It transforms into aerosols in 105°C.	[3,8,18,21]
Chemical reaction	Neutral	[8]
Solubility	Lipophilic substance and highly fat soluble (it can easily disseminate into skin, mucosa, brain, kidneys, muscles and liver), negligible solubility in water, may be hydrolyzed in water and soluble in acetone. Water solubility 0.092 g/100 g at 22°C.	[3,8,22]
Stability	In low temperatures, sulfur mustard remains stable in clothing and soil for months. It remains in the battlefields (for example beside the moats in World War I) and can be found in the amount of 1–25 mg/m3 in 6–12 inch depth of the soil. In moderate temperatures with mild winds sulfur mustard can remain stable for more than a week . Different forms of SM can be stored in the soil for up to 10 years.	[8,23]
Boiling point	215 - 227°C	[1,8]
Melting point	13-14°C	[1]
Freezing point	14°C (its freezing point is decreased by chlorobenzene)	[8]
Volatility	610 mg/m3 in 20°C	[8]
Specific Gravity	1.27(in liquid form than water and in gas form is heavier than air)	[21,24]
Vap. Pres.	0.072 mmHg at 20°C	[8]
Molecular weight	159.08	[1]
Evaporation degree	SM evaporates at 15°C, in warm temperatures becomes less stable and its vapor form increases, and at night it sediments because of decreased temperature.	[7]
Density	SM is heavier than water when in the form of liquid and heavier than air when in the form of vapor or gas. Liquid density (1.274g/ml, Vapor Density (5.4), Solid Density (Crystal) 1.37 g/ml at 20°C	[1,8]
Half life	5 min in 37°C	[3]
Permeability	SM penetrates the porous clothing and food and plants, easily penetrates into the cell membrane of most tissues, wood, leather (it an permeate leather and regular clothing in a few minutes and reach body tissues), rubber, plastics (can easily pass through regular or plastic breathing masks and rubber or plastic clothing can protect the body for a few hours) and remains active for a long time in cold or moderate temperatures.	[7,23,25]
Absorption in the body	Eighty percent of the SM gas is evaporated and the remaining 20% penetrates the body. Of the 20%, 12% remains on the skin and 8% is absorbed systemically. Absorption is done through moist tissues like respiratory system, axillary area, genital area/groins and eyes. Tissues with higher metabolism are more sensitive to this toxic gas.	[1,3,8,26]
Metabolites	The main metabolite of SM in the urine is thiodiglycol which can be detected by chromatography with1ng /ml sensitivity.	[3]
Excretion	Fifty percent of the absorbed SM in the body is conjugated with aminoacid lecithin producing di-cystylethyl sulfone which is excreted through the kidneys.	[22]
Anti-toxin	Unfortunately there is no specific antitoxin for SM gas	[6]
Applications	Except for chemical warfare, a nitrogen analogue of SM is now being used in chemotherapy for treatment of leukemia. This therapeutic agent is called Mustargen	[1]