Methane

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]

Biomedical References

No

Explanatory Notes

For TLV, see Appendix F: Minimal Oxygen Content (Simple asphyxiant, Explosive hazard); [ACGIH]; Flash point = -306 deg F;

burn readily

Other Poison

Simple Asphyxiant

Diseases

Occupational diseases associated with exposure to this agent:

• Asphyxiation, simple

Processes

Industrial Processes with risk of exposure:

• Farming (Respiratory Hazards)
• Mining
• Sewer and Wastewater Treatment

Activities

Activities with risk of exposure:

• Smoking cigarettes