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] |
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 |
TLV (ACGIH) |
1000 ppm |
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: METHANE
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