Helium

1Identification

Name

Helium

IUPAC name

helium

CAS number

7440-59-7

EC number

275-187-7

Molecular formula

He

Molecular weight

4.0026 g/mol

InChIKey

SWQJXJOGLNCZEY-UHFFFAOYSA-N

SMILES

[He]

PubChem CID

23987

Synonyms

HELIUM, Atomic helium, Helium-4, p-Helium, O-Helium, Helium (USP), Helium 4, Helium [USP], INS NO.939, E939, INS-939, E-939, RefChem:5878, HELIUM, USP

Recommended uses

• Used as an inert gas in arc welding; Also used in balloons, airships, lamps, electronic tubes, and cryogenic applications; [ACGIH] Also used to replace nitrogen in breathing supply of high-pressure divers and as a coolant for nuclear reactors; [Merck Index # 4630] Also used for leak detection, growing crystals (germanium and silicon), transferring heat, and producing lasers; [Hawley]
  Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
• Welding [Category: Weld] Semiconductor Manufacturing [Category: Industry]
  Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
• Liquid helium (the most volatile liquid known) as cryogen for the production of low temps, in MRI machines. Gas in manufacture of semiconducting devices; in detection devices for leaks in vacuum systems; in Ne-He lasers; in gas mixtures as the working fluid in plasma devices; in mixtures with Ne and Ar in Geiger counters. Q-Gas, a mixture of 98.7% He and 1.3% butane, has been used as a filing for gas-flow Geiger counters. Gas as a shield in gas tungsten-arc welding, in metal processing; substitute for N2 in synthetic breathing gas for deep sea divers and workers in high pressure conditions; coolant in high temperature nuclear reactors; carrier gas in gas-liquid and gas-solid chromatography;
  Hazardous Substances Data Bank (HSDB)
• Processing aids, specific to petroleum production Not Known or Reasonably Ascertainable Heat transferring agent
  EPA Chemical Data Reporting (CDR)

Use categories: Food additives · Animal Drugs -> FDA Approved Animal Drug Products (Green Book) -> Active Ingredients · Food Additives -> FOOD_ADDITIVE; PROCESSING_AID -> JECFA Functional Classes

Description

• Helium appears as a colorless, odorless, noncombustible gas. Can asphyxiate. Inhalation causes the voice to become squeaky (Mickey Mouse voice). Exposure of the container to prolonged heat or fire can cause it to rupture violently and rocket. If liquefied, contact of the very cold liquid with water causes violent boiling. Pressures may build to dangerous levels if the liquid contacts water in a closed container. Used in arc welding, to trace leaks in refrigeration and other closed systems and as a lifting gas for lighter-than-air aircraft.
  CAMEO Chemicals
• Helium is a colorless odorless gas. It is lighter than air. It is nonflammable and is only slightly soluble in water. It is chemically inert. When shipped as a liquid it is very cold and will solidify all other gases. Contact with the liquid will cause severe frostbite. Liquid helium is used in cryogenic research and as a nuclear reactor coolant.
  CAMEO Chemicals
• Helium(0) is a monoatomic helium. It has a role as a NMR chemical shift reference compound and a member of food packaging gas.
  ChEBI

2Hazard identification

Signal word

Warning

Pictograms

GHS04

Classification source

European Chemicals Agency (ECHA)

Precautionary statements

Other reported classifications

2 classification records exist across sources. Differences usually reflect purity, physical form or impurities.

Health hazards

• Excerpt from ERG Guide 120 [Gases - Inert (Including Refrigerated Liquids)]: Vapors may cause dizziness or asphyxiation without warning, especially when in closed or confined areas. Vapors from liquefied gas are initially heavier than air and spread along ground. Contact with gas, liquefied gas or cryogenic liquids may cause burns, severe injury and/or frostbite. (ERG, 2024)
  CAMEO Chemicals
• · Vapors may cause dizziness or asphyxiation without warning, especially when in closed or confined areas. · Vapors from liquefied gas are initially heavier than air and spread along ground. · Contact with gas, liquefied gas or cryogenic liquids may cause burns, severe injury and/or frostbite.
  Emergency Response Guidebook (ERG)

Fire hazards

• Excerpt from ERG Guide 120 [Gases - Inert (Including Refrigerated Liquids)]: Non-flammable gases. Containers may explode when heated. Ruptured cylinders may rocket. (ERG, 2024)
  CAMEO Chemicals
• · Non-flammable gases. · Containers may explode when heated. · Ruptured cylinders may rocket.
  Emergency Response Guidebook (ERG)
• Not combustible. Heating will cause rise in pressure with risk of bursting.
  ILO-WHO International Chemical Safety Cards (ICSCs)

Hazards summary

• Simple asphyxiant; Evaporating liquid can cause frostbite; [ICSC]
  Haz-Map, Information on Hazardous Chemicals and Occupational Diseases

3Composition / information on ingredients

This page describes the pure substance. Commercial products may be solutions or mixtures. Check Section 3 of your supplier's SDS for concentrations and other ingredients.

4First-aid measures

• Excerpt from ERG Guide 120 [Gases - Inert (Including Refrigerated Liquids)]: 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. (ERG, 2024)
  CAMEO Chemicals
• General First Aid: · Call 911 or emergency medical service. · Ensure that medical personnel are aware of the material(s) involved, take precautions to protect themselves and avoid contamination. · Move victim to fresh air if it can be done safely. · Administer oxygen if breathing is difficult. · If victim is not breathing: -- DO NOT perform mouth-to-mouth resuscitation; the victim may have ingested or inhaled the substance. -- If equipped and pulse detected, wash face and mouth, then give artificial respiration using a proper respiratory medical device (bag-valve mask, pocket mask equipped with a one-way valve or other device).
  Emergency Response Guidebook (ERG)

Symptoms of exposure

• Dizziness. Lethargy. Headache. Suffocation.
  ILO-WHO International Chemical Safety Cards (ICSCs)
• ON CONTACT WITH LIQUID: FROSTBITE.
  ILO-WHO International Chemical Safety Cards (ICSCs)

5Fire-fighting measures

• Suitable extinguishing media: Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide. Special protective equipment for firefighters: Wear self contained breathing apparatus for fire fighting if necessary.
  Hazardous Substances Data Bank (HSDB)
• Use water spray to cool unopened containers.
  Hazardous Substances Data Bank (HSDB)
• If material involved in fire: Extinguish fire using agent suitable for type of surrounding fire. (Material itself does not burn or burns with difficulty.) Cool all affected containers with flooding quantities of water. Apply water from as far a distance as possible. /Helium compressed; Helium refrigerated liquid/
  Hazardous Substances Data Bank (HSDB)

6Accidental release measures

Isolation and evacuation

• Excerpt from ERG Guide 120 [Gases - Inert (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 100 meters (330 feet). 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)
  CAMEO Chemicals
• 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 100 meters (330 feet). 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.
  Emergency Response Guidebook (ERG)

Spill cleanup

• Ventilation. NEVER direct water jet on liquid. Personal protection: self-contained breathing apparatus.
  ILO-WHO International Chemical Safety Cards (ICSCs)
• Personal precautions: Avoid breathing vapors, mist or gas. Ensure adequate ventilation. Evacuate personnel to safe areas. Environmental precautions: Do not let product enter drains. Methods and materials for containment and cleaning up: Clean up promptly by sweeping or vacuum.
  Hazardous Substances Data Bank (HSDB)
• Ventilation. NEVER direct water jet on liquid. Personal protection: self-contained breathing apparatus. /Helium (liquefied, cooled)/
  Hazardous Substances Data Bank (HSDB)

7Handling and storage

• Fireproof if in building. Keep in a well-ventilated room.
  ILO-WHO International Chemical Safety Cards (ICSCs)
• Conditions for safe storage: Keep container tightly closed in a dry and well-ventilated place.
  Hazardous Substances Data Bank (HSDB)

8Exposure controls / personal protection

Personal protective equipment

• Excerpt from ERG Guide 120 [Gases - Inert (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 or solids. (ERG, 2024)
  CAMEO Chemicals
• Respiratory protection Where risk assessment shows air-purifying respirators are appropriate use a full-face respirator with multi-purpose combination (US) or type AXBEK (EN 14387) respirator cartridges as a backup to engineering controls. If the respirator is the sole means of protection, use a full-face supplied air respirator. Use respirators and components tested and approved under appropriate government standards such as NIOSH (US) or CEN (EU).
  Hazardous Substances Data Bank (HSDB)
• Handle with gloves.
  Hazardous Substances Data Bank (HSDB)
• Eye protection: Use equipment for eye protection tested and approved under appropriate government standards such as NIOSH (US) or EN 166(EU).
  Hazardous Substances Data Bank (HSDB)

9Physical and chemical properties

10Stability and reactivity

Reactivity

• Chemically inert. These substances undergo no chemical reactions under any known circumstances. They are nonflammable, noncombustible and nontoxic. They can asphyxiate.
  CAMEO Chemicals
• These substances undergo no chemical reactions under any known circumstances. They are nonflammable, noncombustible and nontoxic. They can asphyxiate. Contact of very cold liquefied gas with water may result in vigorous or violent boiling of the product and extremely rapid vaporization due to the large temperature differences involved. If the water is hot, there is the possibility that a liquid "superheat" explosion may occur. Pressures may build to dangerous levels if liquid gas contacts water in a closed container, [Handling Chemicals Safely 1980].
  CAMEO Chemicals
• No rapid reaction with air. No rapid reaction with water.
  CAMEO Chemicals

Incompatible materials and hazardous reactions

• Materials to avoid: Strong oxidizing agents.
  Hazardous Substances Data Bank (HSDB)

Chemical stability

• Chemical stability: Stable under recommended storage conditions.
  Hazardous Substances Data Bank (HSDB)

11Toxicological information

Short-term exposure effects

• The liquid may cause frostbite. Asphyxiation.
  ILO-WHO International Chemical Safety Cards (ICSCs)

12Ecological information

Not available in the public sources we compile. Check Section 12 of the supplier's SDS.

13Disposal considerations

• SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal and plant life; and conformance with environmental and public health regulations.
  Hazardous Substances Data Bank (HSDB)
• Product: Offer surplus and non-recyclable solutions to a licensed disposal company. Contact a licensed professional waste disposal service to dispose of this material. Contaminated packaging: Dispose of as unused product.
  Hazardous Substances Data Bank (HSDB)
• Release to atmosphere.
  Hazardous Substances Data Bank (HSDB)

14Transport information

UN numbers: UN 1046, UN 1963

Shipping name

• UN 1046; Helium, compressed
  Hazardous Substances Data Bank (HSDB)
• UN 1963; Helium, refrigerated liquid (cryogenic liquid)
  Hazardous Substances Data Bank (HSDB)

DOT hazard class

• Helium, compressed
  US Code of Federal Regulations, Hazardous Materials, 49 CFR Part 172
• UN1046
  US Code of Federal Regulations, Hazardous Materials, 49 CFR Part 172
• Div 2.2 Non-flammable compressed gas (49 eCFR § 173.115)
  US Code of Federal Regulations, Hazardous Materials, 49 CFR Part 172

DOT label

• Non-Flammable Gas
  CAMEO Chemicals

UN classification

• UN Hazard Class: 2.2
  ILO-WHO International Chemical Safety Cards (ICSCs)

Emergency Response Guidebook

• 1963 120
  Emergency Response Guidebook (ERG)
• 1046 120
  Emergency Response Guidebook (ERG)

How DOT hazard classes work →

15Regulatory information

• Substance added directly to human food affirmed as generally recognized as safe (GRAS).
  Hazardous Substances Data Bank (HSDB)

Overview of SDS regulations (OSHA HazCom, WHMIS, REACH/CLP) →

16Other information

Compiled from PubChem CID 23987 and the sources it aggregates (attributed inline). Data retrieved 2026-10-12. This summary describes the pure substance and is not a supplier SDS.