PHYSICAL STATE @ 20° C. (68° F.) – Crystalline solid
FLASH POINT – None
FREEZING/MELTING POINT – 195° C. (383° F.)
BOILING POINT – 410° C. (770° F.)
DECOMPOSITION TEMPERATURE – Above 195° C. (383° F.)
SOLID DENSITY – 1.65 g/cc @ 20° C. (68° F.)
VAPOR PRESSURE (mm/Hg) – Negligible, forms little vapor
VOLATILITY (mg/m3) – Negligible, forms little vapor
ODOR – None but irritating
APPEARANCE – Light green to bright canary yellow crystalline solid
SOLUBILITY – Insoluble in water
MEDIAN INCAPACITATING DOSAGE (ID50) – 22 mg-min/m3 for one minute, 8 mg-min/m3 for one hour
MEDIAN LETHAL DOSAGE (LD50) – 11,000 mg-min/m3 for two minutes plus
PERSISTENCY – Contaminates area for up to two weeks
INHALATION TOXICITY – Severe irritation
SKIN TOXICITY – Irritating
EYE TOXICITY – Irritating
RATE OF ACTION – Very rapid, immediate irritation to the eyes and skin,
SYMPTOMS (PHYSIOLOGICAL ACTION) – Fluid buildup in lungs, severe nasal congestion, headache, dizziness, and cold or flu-like symptoms follow rapidly, nausea and vomiting, which can be violent, follows within minutes or hours (depending on concentration) after inhalation
TREATMENT – Remove from exposure
DURATION OF EFFECTIVENESS – Short
PROTECTION – Gas mask
DECONTAMINATION – Wash down with bleaching powder
USE – Grenades
The original version of this chemical weapon was initially discovered, and patented, in German in 1915, but the process for making it was complicated and time consuming so it was not employed in WWI. Both the United States and Britain working on a simplified version discovered Diphenylaminechlorarsine in 1918. The agent was named “Adamsite” here in the US after its American discoverer Major Roger Adams. Adamsite was not used by the Americans during WWI, but did go into production in the post-war years. The agent is considered a Maskenbrecher [Mask Breaker] as coined by the Germans, and agent that forces affected individuals to remove their gas masks due to violent sneezing or vomiting. The removal of gas masks would expose the personnel to other, possibly more injurious or lethal, chemical agents.
To employ Adamsite, or DM as it was code named, the solid agent needed to be carried in a pyrotechnic burning compound to carry the agent in the resulting smoke cloud. As DM does not take immediate effect as a vomiting agent, it was often mixed with CN tear gas, such as in the M6 gas grenade produced in the United States. The CN would force people to immediately mask up as protection to the tear gas, the DM would then start taking effect moments later. The toxic nature of DM, as an arsenic compound, prevented it from being widely used in the United States as a riot control agent. Burning pyrotechnic charges with intermixed DM forms a bright yellow to green (depending on purity of the DM) smoke cloud.
