Methyl Isocyanate

CAS RN: 624-83-9

DOT Emergency Guidelines

If THERE IS NO FIRE, go directly to protective distances to obtain initial isolation and protective action distances. IF THERE IS A FIRE, or IF A FIRE IS INVOLVED, go directly to the EVACUATION information shown below under PUBLIC SAFETY.

GUIDE 155
Substances - Toxic and/or Corrosive (Flammable / Water-Sensitive)
POTENTIAL HAZARDS
FIRE OR EXPLOSION
· HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames.
· Vapors form explosive mixtures with air: indoors, outdoors and sewers explosion hazards.
· Most vapors are heavier than air. They will spread along the ground and collect in low or confined areas (sewers, basements, tanks, etc.).
· Vapors may travel to source of ignition and flash back.
· Those substances designated with a (P) may polymerize explosively when heated or involved in a fire.
· Substance will react with water (some violently) releasing flammable, toxic or corrosive gases and runoff.
· Contact with metals may evolve flammable hydrogen gas.
· Containers may explode when heated or if contaminated with water.
HEALTH
· TOXIC; inhalation, ingestion or contact (skin, eyes) with vapors, dusts or substance may cause severe injury, burns or death.
· Bromoacetates and chloroacetates are extremely irritating/lachrymators (cause eye irritation and flow of tears).
· Reaction with water or moist air will release toxic, corrosive or flammable gases.
· Reaction with water may generate much heat that will increase the concentration of fumes in the air.
· Fire will produce irritating, corrosive and/or toxic gases.
· Runoff from fire control or dilution water may be corrosive and/or toxic and cause environmental contamination.
PUBLIC SAFETY
· CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper not available or no answer, refer to appropriate telephone number listed on the inside back cover.
· Keep unauthorized personnel away.
· Stay upwind, uphill and/or upstream.
· Ventilate closed spaces before entering, but only if properly trained and equipped.
PROTECTIVE CLOTHING
· 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.
EVACUATION
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
· For highlighted materials: see Table 1 - .
· For non-highlighted materials: increase the immediate precautionary measure distance, in the downwind direction, as necessary.
Fire
· If tank, rail car or tank truck 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.
In Canada, an Emergency Response Assistance Plan (ERAP) may be required for this product. Please consult the shipping paper and/or the ERAP Program Section.
EMERGENCY RESPONSE
FIRE
· Note: Most foams will react with the material and release corrosive/toxic gases.
CAUTION: For Acetyl chloride (UN1717), use CO2 or dry chemical only.
Small Fire
· CO2, dry chemical, dry sand, alcohol-resistant foam.
Large Fire
· Water spray, fog or alcohol-resistant foam.
· FOR CHLOROSILANES, DO NOT USE WATER; use AFFF alcohol-resistant medium-expansion foam.
· If it can be done safely, move undamaged containers away from the area around the fire.
· Avoid aiming straight or solid streams directly onto the product.
Fire Involving Tanks or Car/Trailer Loads
· 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 engulfed in fire.
SPILL OR LEAK
· ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area.
· All equipment used when handling the product must be grounded.
· Do not touch damaged containers or spilled material unless wearing appropriate protective clothing.
· Stop leak if you can do it without risk.
· A vapor-suppressing foam may be used to reduce vapors.
· FOR CHLOROSILANES, use AFFF alcohol-resistant medium-expansion foam to reduce vapors.
· DO NOT GET WATER on spilled substance or inside containers.
· Use water spray to reduce vapors or divert vapor cloud drift. Avoid allowing water runoff to contact spilled material.
· Prevent entry into waterways, sewers, basements or confined areas.
Small Spill
· Cover with DRY earth, DRY sand or other non-combustible material followed with plastic sheet to minimize spreading or contact with rain.
· Use clean, non-sparking tools to collect material and place it into loosely covered plastic containers for later disposal.
FIRST AID
· Call 911 or emergency medical service.
· Ensure that medical personnel are aware of the material(s) involved and take precautions to protect themselves.
· Move victim to fresh air if it can be done safely.
· Give artificial respiration if victim is not breathing.
· Do not perform mouth-to-mouth resuscitation if victim ingested or inhaled the substance; wash face and mouth before giving artificial respiration. Use a pocket mask equipped with a one-way valve or other proper respiratory medical device.
· Administer oxygen if breathing is difficult.
· Remove and isolate contaminated clothing and shoes.
· In case of contact with substance, immediately flush skin or eyes with running water for at least 20 minutes.
· For minor skin contact, avoid spreading material on unaffected skin.
· Keep victim calm and warm.
· Effects of exposure (inhalation, ingestion or skin contact) to substance may be delayed.
ERG 2020

Find more information on this substance at: PubChem, PubMed