Agent Name

Methane

CAS Number

74-82-8

Formula

C-H4

Major Category

Toxic Gases & Vapors

Synonyms

Biogas; Fire Damp; Marsh gas; Methane; Methyl hydride; R 50 (refrigerant); [ChemIDplus] UN1971; UN1972;

Category

Simple Asphyxiants

Description

Colorless, odorless gas; [Merck Index] Vapor density = 0.554 (lighter than air); [HSDB]

Sources/Uses

In the USA 85% of natural gas is methane. [Merck Index] Produced by decaying matter in swamps and marshes; [Hawley]

Comments

The "Critical Effects" for aliphatic hydrocarbon gases are CNS depression and cardiac sensitization. "From a toxicologic standpoint, methane and ethane are practically inert; however, at very high concentrations, they act as a simple asphyxiant and can cause suffocation by displacement of oxygen from breathing atmosphere, below the critical level of 16% oxygen that is required to sustain life." [ACGIH] Simple asphyxiant; Evaporating liquid can cause frostbite; [ICSC]

Exposure Assessment
Skin Designation (ACGIH)

No

Explanatory Notes

For TLV, see Aliphatic hydrocarbon gases: Alkane (C1-C4); [ACGIH]; Flash point = -306 deg F;

Flammability (NFPA)

4: Burns readily

Adverse Effects
Other Poison

Simple Asphyxiant

Links to Other NLM Databases
Health Studies

Human Health Effects from Hazardous Substances Data Bank:

Toxicity Information

Chemical Information

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Biomedical References

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Related Information in HazMap
Diseases

Occupational diseases associated with exposure to this agent:

Processes

Industrial Processes with risk of exposure:

Activities

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