GUIDE
125

Gases - Toxic and/or Corrosive

• TOXIC and/or CORROSIVE; may be fatal if inhaled, ingested or absorbed through skin.
• Vapors are extremely irritating and corrosive.
• Contact with gas or liquefied gas may cause burns, severe injury and/or frostbite.
• Fire will produce irritating, corrosive and/or toxic gases.
• Runoff from fire control or dilution water may cause environmental contamination.

• Some may burn but none ignite readily.
• Vapors from liquefied gas are initially heavier than air and spread along ground.
• Some of these materials may react violently with water.
• Cylinders exposed to fire may vent and release toxic and/or corrosive gas through pressure relief devices.
• Containers may explode when heated.
• Ruptured cylinders may rocket.
• For UN1005: Anhydrous ammonia, at high concentrations in confined spaces, presents a flammability risk if a source of ignition is introduced.

• 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.
• Many gases are heavier than air and will spread along the ground and collect in low or confined areas (sewers, basements, tanks, etc.).
• Ventilate closed spaces before entering, but only if properly trained and equipped.

• 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.

• Isolate spill or leak area for at least 100 meters (330 feet) in all directions.

• For highlighted materials: see Table 1 - Initial Isolation and Protective Action Distances.
• For non-highlighted materials: increase the immediate precautionary measure distance, in the downwind direction, as necessary.

• If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 1600 meters (1 mile) in all directions; also, consider initial evacuation for 1600 meters (1 mile) in all directions.

• Dry chemical or CO₂.

• Water spray, fog or regular foam.
• If it can be done safely, move undamaged containers away from the area around the fire.
• Do not get water inside containers.
• Damaged cylinders should be handled only by specialists.

• Fight fire from maximum distance or use unmanned master stream devices or monitor nozzles.
• Cool containers with flooding quantities of water until well after fire is out.
• Do not direct water at source of leak or safety devices; icing may occur.
• 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.

• Do not touch or walk through spilled material.
• Stop leak if you can do it without risk.
• If possible, turn leaking containers so that gas escapes rather than liquid.
• Prevent entry into waterways, sewers, basements or confined areas.
• Do not direct water at spill or source of leak.
• Use water spray to reduce vapors or divert vapor cloud drift. Avoid allowing water runoff to contact spilled material.
• Isolate area until gas has dispersed.

• In case of contact with liquefied gas, only medical personnel should attempt thawing frosted parts.
• In case of skin contact with hydrogen fluoride, anhydrous (UN1052), if calcium gluconate gel is available, rinse 5 minutes, then apply gel. Otherwise, continue rinsing until medical treatment is available.

ERG 2024