METHYLDICHLOROARSINE

A chemical warfare blister agent. Very toxic by inhalation. A colorless liquid with an agreeable odor. Denser than water. Painful burns on contact.

• Strong Reducing Agent
• Water-Reactive
• Air-Reactive

Decomposes slowly in water to form a corrosive solution of HCl.

For information on chemical warfare blister agents see the ERG Criminal or Terrorist Use of CBR Agents. (ERG, 2024)

Excerpt from ERG Guide 152 [Substances - Toxic (Combustible)]:

Combustible material: may burn but does not ignite readily. Containers may explode when heated. Those substances designated with a (P) may polymerize explosively when heated or involved in a fire. Runoff may pollute waterways. Substance may be transported in a molten form. (ERG, 2024)

For information on chemical warfare blister agents see the ERG Criminal or Terrorist Use of CBR Agents. (ERG, 2024)

Excerpt from ERG Guide 152 [Substances - Toxic (Combustible)]:

Highly toxic, may be fatal if inhaled, ingested or absorbed through skin. Contact with molten substance may cause severe burns to skin and eyes. Avoid any skin contact. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause environmental contamination. (ERG, 2024)

METHYLDICHLOROARSINE is a reducing agent. Reacts rapidly and dangerously with oxygen and with other oxidizing agents, even weak ones. Can ignite on contact with alcohols. Incompatible with acids, alcohols, amines, and aldehydes. May be ignited by heat, sparks or flames. May re-ignite after fire is extinguished. In one instance, reaction with chlorine rapidly produced gaseous chloromethane, which led to an over pressurization failure [J. Chem. Soc., Dalton Trans., 1976, 1479].

• Acyl Halides, Sulfonyl Halides, and Chloroformates

Use caution: Liquids with this reactive group classification have been known to react with the absorbents listed below.

• Cellulose-Based Absorbents
• Mineral-Based & Clay-Based Absorbents
• Dirt/Earth

For initial isolation and protective action distances for chemical warfare blister agents see the Chemical Warfare Agents table in the ERG Criminal or Terrorist Use of CBR Agents. (ERG, 2024)

Excerpt from ERG Guide 152 [Substances - Toxic (Combustible)]:

IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids.

SPILL: See ERG Table 1 - Initial Isolation and Protective Action Distances on the UN/NA 1556 datasheet.

FIRE: If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2024)

For information on chemical warfare blister agents see the ERG Criminal or Terrorist Use of CBR Agents. (ERG, 2024)

Excerpt from ERG Guide 152 [Substances - Toxic (Combustible)]:

SMALL FIRE: Dry chemical, CO2 or water spray.

LARGE FIRE: Water spray, fog or regular foam. If it can be done safely, move undamaged containers away from the area around the fire. Dike runoff from fire control for later disposal. Avoid aiming straight or solid streams directly onto the product.

FIRE INVOLVING TANKS, RAIL TANK CARS OR HIGHWAY TANKS: Fight fire from maximum distance or use unmanned master stream devices or monitor nozzles. Do not get water inside containers. Cool containers with flooding quantities of water until well after fire is out. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank. ALWAYS stay away from tanks in direct contact with flames. For massive fire, use unmanned master stream devices or monitor nozzles; if this is impossible, withdraw from area and let fire burn. (ERG, 2024)

For information on chemical warfare blister agents see the ERG Criminal or Terrorist Use of CBR Agents. (ERG, 2024)

Excerpt from ERG Guide 152 [Substances - Toxic (Combustible)]:

ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area. Do not touch damaged containers or spilled material unless wearing appropriate protective clothing. Stop leak if you can do it without risk. Prevent entry into waterways, sewers, basements or confined areas. Cover with plastic sheet to prevent spreading. Absorb or cover with dry earth, sand or other non-combustible material and transfer to containers. DO NOT GET WATER INSIDE CONTAINERS. (ERG, 2024)

For information on chemical warfare blister agents see the ERG Criminal or Terrorist Use of CBR Agents. (ERG, 2024)

Excerpt from ERG Guide 152 [Substances - Toxic (Combustible)]:

Wear positive pressure self-contained breathing apparatus (SCBA). Wear chemical protective clothing that is specifically recommended by the manufacturer when there is NO RISK OF FIRE. Structural firefighters' protective clothing provides thermal protection but only limited chemical protection. (ERG, 2024)

No information available.

For information on chemical warfare blister agents see the ERG Criminal or Terrorist Use of CBR Agents. (ERG, 2024)

Excerpt from ERG Guide 152 [Substances - Toxic (Combustible)]:

Refer to the "General First Aid" section. Specific First Aid: Removal of solidified molten material from skin requires medical assistance. (ERG, 2024)

• ARSINE, DICHLOROMETHYL-
• DICHLOROMETHYLARSINE
• MD (CHEMICAL WARFARE AGENT)
• METHYLARSINE DICHLORIDE
• METHYLDICHLOROARSINE