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Chemical Datasheet
HYDROGEN |
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Chemical Identifiers
CAS Number |
UN/NA Number |
DOT Hazard Label |
USCG CHRIS Code |
- 1333-74-0
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NIOSH Pocket Guide |
International Chem Safety Card |
none
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NFPA 704
General Description
Hydrogen is a colorless, odorless gas. It is easily ignited. Once ignited it burns with a pale blue, almost invisible flame. The vapors are lighter than air. It is flammable over a wide range of vapor/air concentrations. Hydrogen is not toxic but is a simple asphyxiate by the displacement of oxygen in the air. Under prolonged exposure to fire or intense heat the containers may rupture violently and rocket. Hydrogen is used to make other chemicals and in oxyhydrogen welding and cutting.
Hazards
Reactivity Alerts
Air & Water Reactions
Highly flammable.
Fire Hazard
Excerpt from ERG Guide 115 [Gases - Flammable (Including Refrigerated Liquids)]:
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. (ERG, 2020)
Health Hazard
Excerpt from ERG Guide 115 [Gases - Flammable (Including Refrigerated Liquids)]:
Vapors may cause dizziness or asphyxiation without warning. Some may be irritating if inhaled at high concentrations. Contact with gas or liquefied gas may cause burns, severe injury and/or frostbite. Fire may produce irritating and/or toxic gases. (ERG, 2020)
Reactivity Profile
Finely divided platinum and some other metals will cause a mixture of hydrogen and oxygen to explode at ordinary temperatures. If a jet of hydrogen in air impinges on platinum black the metal surface gets hot enough to ignite the gases, [Mellor 1:325(1946-1947)]. Explosive reactions occur upon ignition of mixtures of nitrogen trifluoride with good reducing agents such as ammonia, hydrogen, hydrogen sulfide or methane. Mixtures of hydrogen, carbon monoxide, or methane and oxygen difluoride are exploded when a spark is discharged, [Mellor 2, Supp. 1:192(1956)]. An explosion occurred upon heating 1'-pentol and 1''-pentol under hydrogen pressure. It appears that this acetylenic compound under certain conditions suddenly breaks down to form elemental carbon, hydrogen, and carbon monoxide with the release of sufficient energy to develop pressures in excess of 1000 atmospheres, [AIChE Loss Prevention, p1, (1967)].
Belongs to the Following Reactive Group(s)
Potentially Incompatible Absorbents
No information available.
Response Recommendations
Isolation and Evacuation
Excerpt from ERG Guide 115 [Gases - Flammable (Including Refrigerated Liquids)]:
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 car or tank truck 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 BLEVE - SAFETY PRECAUTIONS (ERG page 366). (ERG, 2020)
Firefighting
Excerpt from ERG Guide 115 [Gases - Flammable (Including Refrigerated Liquids)]:
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 engulfed in fire. For massive fire, use unmanned master stream devices or monitor nozzles; if this is impossible, withdraw from area and let fire burn. (ERG, 2020)
Non-Fire Response
Excerpt from ERG Guide 115 [Gases - Flammable (Including Refrigerated Liquids)]:
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. (ERG, 2020)
Protective Clothing
Excerpt from ERG Guide 115 [Gases - Flammable (Including Refrigerated Liquids)]:
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. (ERG, 2020)
DuPont Tychem® Suit Fabrics
No information available.
First Aid
Excerpt from ERG Guide 115 [Gases - Flammable (Including Refrigerated Liquids)]:
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. Administer oxygen if breathing is difficult. Remove and isolate contaminated clothing and shoes. Clothing frozen to the skin should be thawed before being removed. In case of contact with liquefied gas, thaw frosted parts with lukewarm water. In case of burns, immediately cool affected skin for as long as possible with cold water. Do not remove clothing if adhering to skin. Keep victim calm and warm. (ERG, 2020)
Physical Properties
Flash Point: data unavailable
Lower Explosive Limit (LEL):
4 %
(USCG, 1999)
Upper Explosive Limit (UEL):
75 %
(USCG, 1999)
Autoignition Temperature:
1065°F
(USCG, 1999)
Melting Point:
-434°F
(USCG, 1999)
Vapor Pressure: data unavailable
Vapor Density (Relative to Air): data unavailable
Specific Gravity:
0.071
at -423.4°F
(USCG, 1999)
Boiling Point:
-423°F
at 760 mmHg
(USCG, 1999)
Molecular Weight:
2
(USCG, 1999)
Water Solubility: data unavailable
Ionization Energy/Potential: data unavailable
IDLH: data unavailable
AEGLs (Acute Exposure Guideline Levels)
No AEGL information available.
ERPGs (Emergency Response Planning Guidelines)
No ERPG information available.
Regulatory Information
EPA Consolidated List of Lists
Regulatory Name |
CAS Number/ 313 Category Code |
EPCRA 302 EHS TPQ |
EPCRA 304 EHS RQ |
CERCLA RQ |
EPCRA 313 TRI |
RCRA Code |
CAA 112(r) RMP TQ |
Hydrogen |
1333-74-0 |
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10000 pounds |
(EPA List of Lists, 2022)
CISA Chemical Facility Anti-Terrorism Standards (CFATS)
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RELEASE |
THEFT |
SABOTAGE |
Chemical of Interest |
CAS Number |
Min Conc |
STQ |
Security Issue |
Min Conc |
STQ |
Security Issue |
Min Conc |
STQ |
Security Issue |
Hydrogen |
1333-74-0 |
1.00 % |
10000 pounds |
flammable |
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(CISA, 2007)
OSHA Process Safety Management (PSM) Standard List
No regulatory information available.
Alternate Chemical Names
- DIHYDROGEN
- HYDROGEN
- HYDROGEN (H2)
- HYDROGEN MOLECULE
- HYDROGEN, COMPRESSED
- HYDROGEN, GAS
- MOL. HYDROGEN
- MOLECULAR HYDROGEN
- ORTHOHYDROGEN
- PARAHYDROGEN
- PROTIUM