Argon

1Identification

Name

Argon

IUPAC name

argon

CAS number

7440-37-1

EC number

231-147-0

Molecular formula

Ar

Molecular weight

39.9 g/mol

InChIKey

XKRFYHLGVUSROY-UHFFFAOYSA-N

SMILES

[Ar]

PubChem CID

23968

Synonyms

ARGON, Argon-40, Argon, Elemental, Argon 40, AR, KHLADON R 740, INS NO.938, E-938, INS-938, R 740, RefChem:113993, argon atom, Argon36, argon(0)

Recommended uses

• Used as an inert gas in arc welding, semiconductor doping, and metal refining (blanketing agent); Also used as an inert gas in electric lamps and ionization chambers; [ACGIH] Also used in geological dating and cryogenic applications; [Merck Index]
  Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
• Metal Preparation and Pouring [Category: Foundry] Welding [Category: Weld] Semiconductor Manufacturing [Category: Industry] Metal Extraction and Refining [Category: Industry]
  Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
• Smoking cigarettes [Category: Food & Drugs]
  Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
• Not Known or Reasonably Ascertainable
  EPA Chemical Data Reporting (CDR)
• Not Known or Reasonably Ascertainable
  EPA Chemical Data Reporting (CDR)

Use categories: Food additives · Food Additives -> PROPELLANT -> JECFA Functional Classes

Description

• Argon appears as a colorless odorless noncombustible gas. Heavier than air and can asphyxiate by displacement of air. 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 may cause violent boiling. If the water is hot, there is the possibility that a liquid "superheat" explosion may occur. Contacts with water in a closed container may cause dangerous pressure to build.
  CAMEO Chemicals
• Argon, refrigerated liquid (cryogenic liquid) appears as a colorless noncombustible liquid. Heavier than air. Contact may cause frostbite. May cause asphyxiation by displacement of air. Prolonged exposure to fire or intense heat may cause the container to rupture violently and rocket.
  CAMEO Chemicals
• Argon(0) is a monoatomic argon. It has a role as a neuroprotective agent 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

• 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. /Argon, compressed; Argon, refrigerated liquid/
  Hazardous Substances Data Bank (HSDB)
• If material involved in fire: Do not use water on material itself. /Argon, refrigerated liquid/
  Hazardous Substances Data Bank (HSDB)
• Suitable extinguishing media: Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide. Special protective equipment for fire-fighters: Wear self contained breathing apparatus for fire fighting if necessary.
  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

• Personal protection: self-contained breathing apparatus. Ventilation. NEVER direct water jet on liquid.
  ILO-WHO International Chemical Safety Cards (ICSCs)
• Personal precautions: Avoid breathing vapors, mist or gas. Environmental precautions: No special environmental precautions required. Methods for cleaning up: Wipe up with absorbent material (e.g. cloth, fleece).
  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)
• Keep container tightly closed in a dry and well-ventilated place. Contents under pressure.
  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
• Personnel protection: Wear appropriate chemical protective gloves and goggles. /Argon, compressed; Argon, refrigerated liquid/
  Hazardous Substances Data Bank (HSDB)
• Eye protection: Safety glasses.
  Hazardous Substances Data Bank (HSDB)
• For prolonged or repeated contact use protective gloves.
  Hazardous Substances Data Bank (HSDB)

9Physical and chemical properties

10Stability and reactivity

Reactivity

• These substances undergo no chemical reactions under any known circumstances. They are nonflammable, noncombustible and nontoxic. They can asphyxiate.
  CAMEO Chemicals
• No rapid reaction with air. No rapid reaction with water.
  CAMEO Chemicals

11Toxicological information

Short-term exposure effects

• Asphyxiation. The liquid may cause frostbite.
  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)

14Transport information

DOT hazard class

• Argon, compressed
  US Code of Federal Regulations, Hazardous Materials, 49 CFR Part 172
• UN1006
  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

• 1006 120
  Emergency Response Guidebook (ERG)
• 1951 120
  Emergency Response Guidebook (ERG)

How DOT hazard classes work →

15Regulatory information

No specific US regulatory listings found in our sources. Check Section 15 of your supplier's SDS for TSCA, SARA 313, CERCLA, Prop 65 and state listings.

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

16Other information

Compiled from PubChem CID 23968 and the sources it aggregates (attributed inline). Data retrieved 2026-10-12. This summary describes the pure substance and is not a supplier SDS.