ERG 2024 · Guide 115

Gases - Flammable (Including Refrigerated Liquids)

UN3468 · Hydrogen in a metal hydride storage system

Also listed as: Hydrogen in a metal hydride storage system contained in equipment · Hydrogen in a metal hydride storage system packed with equipment

Class 2.1

CHEMTREC · 24/7

1-800-424-9300

Right now: Move upwind. Isolate 100 m minimum. Deny entry. Call CHEMTREC with shipping paper in hand.

More contacts →

Potential Hazards

Health

Vapors may cause dizziness or asphyxiation without warning, especially when in closed or confined areas.
Some may be irritating if inhaled at high concentrations.
Contact with gas, liquefied gas or cryogenic liquids may cause burns, severe injury and/or frostbite.
Fire may produce irritating and/or toxic gases.

Fire or explosion

EXTREMELY FLAMMABLE.
Will be easily ignited by heat, sparks or flames.
Will form explosive mixtures with air.
Vapors from liquefied gas are initially heavier than air and spread along ground.
CAUTION: Hydrogen (UN1049), Deuterium (UN1957), Hydrogen, refrigerated liquid (UN1966), Methane (UN1971) and Hydrogen and Methane mixture, compressed (UN2034) are lighter than air and will rise. Hydrogen and Deuterium fires are difficult to detect since they burn with an invisible flame. Use an alternate method of detection (thermal camera, broom handle, etc.)
Vapors may travel to source of ignition and flash back.
Cylinders exposed to fire may vent and release flammable gas through pressure relief devices.
Containers may explode when heated.
Ruptured cylinders may rocket.
CAUTION: When LNG – Liquefied natural gas (UN1972) is released on or near water, product may vaporize explosively.

Public Safety

General

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.).

Protective clothing

Wear positive pressure self-contained breathing apparatus (SCBA).
Structural firefighters' protective clothing provides thermal protection but only limited chemical protection.
Always wear thermal protective clothing when handling refrigerated/cryogenic liquids.

Evacuation

Immediate precautionary measure
Isolate spill or leak area for at least 100 meters (330 feet) in all directions.
Large Spill
Consider initial downwind evacuation for at least 800 meters (1/2 mile).
Fire
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.
In fires involving Liquefied Petroleum Gases (LPG) (UN1075), Butane (UN1011), Butylene (UN1012), Isobutylene (UN1055), Propylene (UN1077), Isobutane (UN1969), and Propane (UN1978), also refer to the "BLEVE – Safety Precautions" section.

Emergency Response

Fire

DO NOT EXTINGUISH A LEAKING GAS FIRE UNLESS LEAK CAN BE STOPPED.
CAUTION: Hydrogen (UN1049), Deuterium (UN1957), Hydrogen, refrigerated liquid (UN1966) and Hydrogen and Methane mixture, compressed (UN2034) will burn with an invisible flame. Use an alternate method of detection (thermal camera, broom handle, etc.)

Small Fire

Dry chemical or CO2.

Large Fire

Water spray or fog.
If it can be done safely, move undamaged containers away from the area around the fire.
CAUTION: For LNG - Liquefied natural gas (UN1972) pool fires, DO NOT USE water. Use dry chemical or high-expansion foam.

Fire Involving Tanks

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.
For massive fire, use unmanned master stream devices or monitor nozzles; if this is impossible, withdraw from area and let fire burn.

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 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.
Use water spray to reduce vapors or divert vapor cloud drift. Avoid allowing water runoff to contact spilled material.
Do not direct water at spill or source of leak.
CAUTION: For LNG - Liquefied natural gas (UN1972), DO NOT apply water, regular or alcohol-resistant foam directly on spill. Use a high-expansion foam if available to reduce vapors.
Prevent spreading of vapors through sewers, ventilation systems and confined areas.
Isolate area until gas has dispersed.
CAUTION: When in contact with refrigerated/cryogenic liquids, many materials become brittle and are likely to break without warning.

First Aid

Refer to the “General First Aid” section.

Specific First Aid:

Clothing frozen to the skin should be thawed before being removed.

In case of contact with liquefied gas, only medical personnel should attempt thawing frosted parts.

In case of burns, immediately cool affected skin for as long as possible with cold water. Do not remove clothing if adhering to skin.

ERG 2024 · Guide 115

Gases - Flammable (Including Refrigerated Liquids)

UN3468 · Hydrogen in a metal hydride storage system

Also listed as: Hydrogen in a metal hydride storage system contained in equipment · Hydrogen in a metal hydride storage system packed with equipment

Class 2.1

CHEMTREC · 24/7

1-800-424-9300

Right now: Move upwind. Isolate 100 m minimum. Deny entry. Call CHEMTREC with shipping paper in hand.

More contacts →

Potential Hazards

Health

Vapors may cause dizziness or asphyxiation without warning, especially when in closed or confined areas.
Some may be irritating if inhaled at high concentrations.
Contact with gas, liquefied gas or cryogenic liquids may cause burns, severe injury and/or frostbite.
Fire may produce irritating and/or toxic gases.

Fire or explosion

EXTREMELY FLAMMABLE.
Will be easily ignited by heat, sparks or flames.
Will form explosive mixtures with air.
Vapors from liquefied gas are initially heavier than air and spread along ground.
CAUTION: Hydrogen (UN1049), Deuterium (UN1957), Hydrogen, refrigerated liquid (UN1966), Methane (UN1971) and Hydrogen and Methane mixture, compressed (UN2034) are lighter than air and will rise. Hydrogen and Deuterium fires are difficult to detect since they burn with an invisible flame. Use an alternate method of detection (thermal camera, broom handle, etc.)
Vapors may travel to source of ignition and flash back.
Cylinders exposed to fire may vent and release flammable gas through pressure relief devices.
Containers may explode when heated.
Ruptured cylinders may rocket.
CAUTION: When LNG – Liquefied natural gas (UN1972) is released on or near water, product may vaporize explosively.

Public Safety

General

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.).

Protective clothing

Wear positive pressure self-contained breathing apparatus (SCBA).
Structural firefighters' protective clothing provides thermal protection but only limited chemical protection.
Always wear thermal protective clothing when handling refrigerated/cryogenic liquids.

Evacuation

Immediate precautionary measure
Isolate spill or leak area for at least 100 meters (330 feet) in all directions.
Large Spill
Consider initial downwind evacuation for at least 800 meters (1/2 mile).
Fire
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.
In fires involving Liquefied Petroleum Gases (LPG) (UN1075), Butane (UN1011), Butylene (UN1012), Isobutylene (UN1055), Propylene (UN1077), Isobutane (UN1969), and Propane (UN1978), also refer to the "BLEVE – Safety Precautions" section.

Emergency Response

Fire

DO NOT EXTINGUISH A LEAKING GAS FIRE UNLESS LEAK CAN BE STOPPED.
CAUTION: Hydrogen (UN1049), Deuterium (UN1957), Hydrogen, refrigerated liquid (UN1966) and Hydrogen and Methane mixture, compressed (UN2034) will burn with an invisible flame. Use an alternate method of detection (thermal camera, broom handle, etc.)

Small Fire

Dry chemical or CO2.

Large Fire

Water spray or fog.
If it can be done safely, move undamaged containers away from the area around the fire.
CAUTION: For LNG - Liquefied natural gas (UN1972) pool fires, DO NOT USE water. Use dry chemical or high-expansion foam.

Fire Involving Tanks

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.
For massive fire, use unmanned master stream devices or monitor nozzles; if this is impossible, withdraw from area and let fire burn.

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 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.
Use water spray to reduce vapors or divert vapor cloud drift. Avoid allowing water runoff to contact spilled material.
Do not direct water at spill or source of leak.
CAUTION: For LNG - Liquefied natural gas (UN1972), DO NOT apply water, regular or alcohol-resistant foam directly on spill. Use a high-expansion foam if available to reduce vapors.
Prevent spreading of vapors through sewers, ventilation systems and confined areas.
Isolate area until gas has dispersed.
CAUTION: When in contact with refrigerated/cryogenic liquids, many materials become brittle and are likely to break without warning.

First Aid

Refer to the “General First Aid” section.

Specific First Aid:

Clothing frozen to the skin should be thawed before being removed.

In case of contact with liquefied gas, only medical personnel should attempt thawing frosted parts.

In case of burns, immediately cool affected skin for as long as possible with cold water. Do not remove clothing if adhering to skin.