TYPE OF AGENT – Lachrymatory (Tear gas)

NAME (CHEMICAL) – o-Chlorobenzalmalononitrile

NAME (NATO) – CS

NAME (COMMON) – CS, Super Tear Gas

DATE OF DISCOVERY – 1928

FORMULA – C₁₀H₅ClN₂

MOLECULAR WEIGHT – 188.5 g/mol

PHYSICAL STATE @ 20° C. (68° F.)  – white or light beige solid

VAPOR DENSITY (AIR = 1.0) – 6.5

FLASH POINT – 197° C. (387° F.)

FREEZING/MELTING POINT – 93 to 95° C. (199 to 203° F.)

BOILING POINT – 310 to 315° C. (590 to 599° F.)

DECOMPOSITION TEMPERATURE – 310 to 315° C. (590 to 599 ° F.)

SOLID DENSITY – 1.296 g/cc (Crystal)

VAPOR PRESSURE (mm/Hg) – 0.35 mg/m³

ODOR – Pepperlike in crystal form, very pungent vapor

APPEARANCE – White or colorless crystalline solid

SOLUBILITY – Insoluble in water

MEDIAN INCAPACITATING DOSAGE (ID50) – 10 to 20 mg-min/m³

MEDIAN LETHAL DOSAGE (LD50) – 25,000 mg-min/m³  for resting men

PERSISTENCY – Very persistent, CS will be absorbed into most porous surfaces including soil, plaster, and many organic solids, retaining some potency possibly for years

INHALATION TOXICITY – CS is considered non-toxic in normal concentrations, causes a sensation of choking when inhaled

SKIN TOXICITY – Primary skin irritant, Irritating but not toxic from short exposures or in open areas

EYE TOXICITY – Extremely irritating but not toxic from short exposures or in open areas

RATE OF ACTION – Immediate, 10 to 60 seconds to full respiratory and eye effects

SYMPTOMS (PHYSIOLOGICAL ACTION) – Extreme burning in the eyes along with heavy tear flows, involuntary closing of eyelids, coughing, difficulty in breathing, chest tightness, runny nose, heavy concentrations can cause nausea and vomiting. Affected individuals are incapable of effecting concerted action. Itching, burning and stinging sensations on skin

TREATMENT – Removal from exposure, flush affected areas with copious amounts of water

DURATION OF EFFECTIVENESS – Incapacitating dosages lose their effectiveness in 5 to 10 minutes after removal from exposure

PROTECTION – Gas mask, rubber gloves and impermeable clothing recommended

DECONTAMINATION – Ventilate area as completely as possible, vacuum crystalline residue, wash down area while wearing protective equipment, copious washing with soap and water for skin.

USE – Common tear agent in grenades, shells, and as a spray powder (95% micropulverized CS, 5% powdered silica)

     O-Chlorobenzalmalononitrile was first synthesized by the British chemists Corson and Stoughton in 1928 and is known by the much more abbreviated, and simpler) name of CS. It has been referred to as “Super Tear Gas” especially by the numbers of US Soldiers exposed to it during training. The effects of CS are generally severe and very fast acting, but only last for about 10 to 30 minutes after removal from exposure. It has become the standard riot control and training tear gas within NATO. CS itself is not a gas so it is normally used in conjunction with a burning agent, which can be as simple as formulated smokeless powder. It is also employed as a micropulverized powder, in combination with 5% Silica Gell to prevent clumping. The microfine particles of the CS agent can be blown out from aircraft, vehicle-mounted systems, or hand-held delivery tanks.

     Heavy concentrations of CS vapor of dust can cause nausea and vomiting. As it stands, CS is very irritating to the nose and throat as well as causing immediate lachrymatory effects. The irritation from CS can cause a feeling of suffocation or dizziness. This can cause people affected by CS to appear disoriented and confused, sometimes highly so. Vapors from CS being burned cause a strong burning sensation on the skin. The burning is very strong when the CS mixes with the sweat on an individual.