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Chemical Sampling Information (CSI)
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General Description

Synonyms: Methyl hydride; Marsh gas; Fire Damp

OSHA IMIS Code Number: 1640

Chemical Abstracts Service (CAS) Registry Number: 74-82-8

NIOSH Registry of Toxic Effects of Chemical Substances (RTECS) Identification Number: PA1490000

Chemical Description and Physical Properties:

colorless, compressed or liquefied gas, with no odor
molecular weight: 16.05
vapor pressure: 258574 mm Hg @ 37.8°C
molecular formula: CH4
boiling point: -161°C
melting point: -183°C

Incompatibilities: Reacts violently with chlorine dioxide and liquid oxygen; and powerful oxidizers such as, bromine pentafluoride, chlorine trifluoride, chlorine, fluorine, iodine heptafluoride, dioxygenyl tetrafluoroborate, dioxygen difluoride, trioxygen difluoride, and liquid oxygen. It is incompatible with halogens or interhalogens. It will react with bromine in light (explosively in direct sunlight).

Exposure Limits

American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Value (TLV): Simple Asphyxiant

Health Factors

Carcinogenic Classification:

International Agency for Research on Cancer (IARC): Group 3, not classifiable as to its carcinogenicity to humans

Potential Symptoms: Drowsiness; unconsciousness; frostbite (from liquid form)

Health Effects: Simple asphyxiant (HE17); Explosive (HE18)

Affected Organs: Skin (contact with liquid form)

Literature Basis:

  • (symptoms)
    International Chemical Safety Cards (WHO/IPCS/ILO): Methane.

Date Last Revised: 06/27/2003

Monitoring Methods used by OSHA

On-Site Sampling Techniques/Methods:

  • device: Detector Tube
    manufacturer: AUER/MSA
    model/type: Natural Gas, MSA P/N 655789
    sampling information: follow manufacturer's instructions
    upper measurement limit: semi-quantitative
    detection limit: approx. 5000 ppm
    overall uncertainty: unknown
    method reference: on-site air secondary (manufacturer)

  • device: Detector Tube
    manufacturer: Dräger
    model/type: Natural Gas Test, order no. CH 20001
    sampling information: 2 strokes
    upper measurement limit: qualitative test
    detection limit: approx. 0.5% vol.
    overall uncertainty: n.a.
    method reference: on-site air secondary (manufacturer)

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