TYPE OF AGENT – Lacrimatory (Tear Gas)

NAME (CHEMICAL) – Chloroacetophenone

NAME (NATO) – CN

NAME (COMMON) – CN, Ni-Stoff (WWI German)

DATE OF DISCOVERY – 1869

MOLECULAR FORMULA – C₆H₅COCH₂CL

MOLECULAR WEIGHT – 154.59 g/mol

PHYSICAL STATE @ 20° C. (68° F.)  – Solid

VAPOR DENSITY (AIR = 1.0) – 5.3

FLASH POINT – 118° C. (244° F.)

FREEZING/MELTING POINT – 54 to 55° C. (129 to 131° F.)

BOILING POINT – 244 to 245° C. (471 to 473° F.)

DECOMPOSITION TEMPERATURE – Stable to boiling point

SOLID DENSITY – 1.32 @ 15° C. (59° F.)

VAPOR PRESSURE (mm/Hg) – 0.0017 mm Hg @ 0° C. (32° F.), 0.0054 mm Hg @ 20° C. (68° F.), 0.158 mm Hg @ 55° C. (131° F.)

VOLATILITY (mg/m³) – 30 mg/m³ @ 0° C., 105 mg/m³ @ 20°C. (68° F.)

ODOR – Fragrant, similar to apple blossoms

APPEARANCE – Colorless to gray or white crystals

SOLUBILITY – Slightly soluble 1.64 g/100 ml @25° C. (77° F.)

MEDIAN INCAPACITATING DOSAGE (ID50) – 20 to 40 mg/min/m³

MEDIAN LETHAL DOSAGE (LD50) – 7,000 mg-min/m³ (used with a solvent), 14,000 mg/min/m³ (used as a smoke carried agent)

PERSISTENCY – Short

INHALATION TOXICITY – Suspected to be around 11,000 mg/min/m³

SKIN TOXICITY – Mild to moderate irritation and pain, increased by moisture or humidity

EYE TOXICITY – Immediate weeping in concentrations of 0.0003 mg per liter

RATE OF ACTION – Immediately, 3 to 10 seconds

SYMPTOMS (PHYSIOLOGICAL ACTION) – Immediate burning pain in eyes with spasmodic blinking and heavy tear production. Runny nose, coughing, sneezing and pain, chest tightness on inhalation along with difficulty in breathing and shortness of breath, can be followed by nausea and salivation

TREATMENT – Rinse eyes with volumes of water, remove to clean air

DURATION OF EFFECTIVENESS – Dependent on exposure time and concentration, initial irritation normally resolves within 20 to 30 minutes of removal from exposure and decontamination (aeration and washing). Eye redness may take up to 1 or 2 days to resolve.

PROTECTION – Gas mask

DECONTAMINATION – Aeration in the field

USE – Common tear agent in grenades and shells

     This tear agent was developed as such by the British at their Porton Down facility. The agent was intended to be a replacement for the much more toxic tear agents that had been used during the war. It was quickly picked up by the United States and manufactured in that country. In 1922, a manufacturing plant for CN was built at Edgewood Arsenal. In 1941, the old plant was torn down and a new plant built in its place to meet the heavy demands of wartime production. The new plant was able to turn out a ton of CN agent a day. CN was used as the standard tear gas agent in the US from the 1930’s well into the 1950s. It was also produced and used by both the German and the Japanese governments during WWII. The agent has some drawbacks in that it cannot be released as a gas. Instead the solid agent is mixed with a smoke-producing fuel and disburses with the smoke. It may also be mixed with a liquid solvent such as alcohol, and utilized as an agent spray. Normally a non-lethal agent, CN can become toxic in high concentrations in closed or confined areas.