TYPE OF AGENT – Vomiting agent (Sternutator)

NAME (CHEMICAL) – Diphenylchlorarsine

NAME (NATO) – DA

NAME (COMMON) – Sneezing gas, Clark I (German)

DATE OF DISCOVERY – 1878

MOLECULAR FORMULA – C₁₂H₁₀AsCl

MOLECULAR WEIGHT – 264.59 g/mol

PHYSICAL STATE @ 20° C. (68° F.)  – Crystalline solid (pure) Liquid (technical grade)

VAPOR DENSITY (AIR = 1.0) – 9.15

FLASH POINT – 350° C. (662° F.)

FREEZING/MELTING POINT – 42° C. (108° F.)

BOILING POINT – 307° C. (585° F.)

DECOMPOSITION TEMPERATURE – 333° C. (631° F.)

LIQUID DENSITY – 1.387 @ 50° C. (122° F.)

SOLID DENSITY – 1.55 g/cc

VAPOR PRESSURE (mm/Hg) – 0.0016 mm Hg @ 20° C. (68° F.)

VOLATILITY (mg/m3) – 7.2 mg/m³ @ 20° C. (68° F.)

ODOR – None or wax-like

APPEARANCE – Colorless crystalline solid, dark brown liquid

SOLUBILITY – Poor, 0.2 gh/100 ml, slowly decomposed by water

MEDIAN INCAPACITATING DOSAGE (ID50) – 1.1 mg/m³ for 10 minutes exposure

MEDIAN LETHAL DOSAGE (LD50) – 3.4 mg/m³ for 10 minutes exposure

PERSISTENCY – Considered a non-persistent agent, incapacitated victims usually are detoxified in 1 to 2 hours.

INHALATION TOXICITY – Toxic

SKIN TOXICITY – Irritating, non-toxic

EYE TOXICITY – Irritating, non-toxic

RATE OF ACTION – Very rapid, within 2 or 3 minutes after 1 minute exposure

SYMPTOMS (PHYSIOLOGICAL ACTION) – Eye and skin pain, irritation to the mucous membranes, causes coughing, runny nose, headache, salivation, violent sneezing, can cause violent vomiting

TREATMENT – Remove from exposure, remove contaminated clothing, artificial respiration if not breathing, wash face and mouth first, administer oxygen, rinse eyes or skin with water

DURATION OF EFFECTIVENESS – 5 to 10 minutes

PROTECTION – Gas mask

DECONTAMINATION – Absorb liquid in sand or inert absorbent, wash down area with chlorine bleach solution

USE – Artillery shells, grenades

     Diphenylchlorarsine was considered by the German military to be a Maskenbrecher [Mask Breaker] an agent that would force men to remove their gas masks due to sneezing or vomiting. Such actions could cause the men to become victims of more lethal agents. It was suspected that the gas would penetrate the masks of the time, but this was not proved true. The agent proved difficult to properly disburse with explosives or sprayers. It was found to be effectively employed when released by heat as a toxic smoke. The failure to properly disburse Diphenylchlorarsine from an explosive shell proved to be one of the few technical mistakes by the Germans in the field of chemical warfare as they loaded some 14 million rounds of artillery ammunition (Blue Cross) with the substance.