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METHYL CHLORIDE ICSC: 0419
Date of Peer Review: March 1999

Chloromethane
Monochloromethane
CAS # 74-87-3 CH3Cl
RTECS # PA6300000 Molecular mass: 50.5
UN # 1063
EC Index # 602-001-00-7
TYPES OF HAZARD / EXPOSURE ACUTE HAZARDS / SYMPTOMS PREVENTION FIRST AID / FIRE FIGHTING
FIRE Highly flammable. Heating will cause rise in pressure with risk of bursting.
NO open flames, NO sparks, and NO smoking.
Shut off supply; if not possible and no risk to surroundings, let the fire burn itself out; in other cases extinguish with water spray.
EXPLOSION Gas/air mixtures are explosive.
Closed system, ventilation, explosion-proof electrical equipment and lighting. Use non-sparking handtools.
In case of fire: keep cylinder cool by spraying with water. Combat fire from a sheltered position.
EXPOSURE
STRICT HYGIENE!

Inhalation Staggering gait. Dizziness. Headache. Nausea. Vomiting.Convulsions. Unconsciousness. See Notes.
Ventilation, local exhaust, or breathing protection.
Fresh air, rest. Artificial respiration may be needed. Refer for medical attention.
Skin MAY BE ABSORBED! ON CONTACT WITH LIQUID: FROSTBITE.
Cold-insulating gloves. Protective clothing.
ON FROSTBITE: rinse with plenty of water, do NOT remove clothes.
Eyes (See Skin).
Safety goggles face shield or eye protection in combination with breathing protection.

Ingestion


SPILLAGE DISPOSAL PACKAGING & LABELLING
Evacuate danger area! Consult an expert! Ventilation. NEVER direct water jet on liquid. Personal protection: complete protective clothing including self-contained breathing apparatus.
EU Classification
Symbol: F+, Xn
R: 12-40-48/20
S: (2-)-9-16-33
UN Classification
UN Hazard Class: 2.1

EMERGENCY RESPONSE STORAGE
Transport Emergency Card: TEC (R)-20S1063 or 20G2F
NFPA Code: H2; F4; R0;
Fireproof. Ventilation along the floor.
IPCS
International
Programme on
Chemical Safety
Prepared in the context of cooperation between the International Programme on Chemical Safety and the Commission of the European Communities IPCS, CEC 2005

SEE IMPORTANT INFORMATION ON BACK
METHYL CHLORIDE ICSC: 0419
IMPORTANT DATA
PHYSICAL STATE; APPEARANCE:
COLOURLESS LIQUEFIED GAS.

PHYSICAL DANGERS:
The gas is heavier than air and may travel along the ground; distant ignition possible, and may accumulate in low ceiling spaces causing deficiency of oxygen. See Notes.

CHEMICAL DANGERS:
The substance decomposes on burning producing toxic and corrosive fumes including hydrogen chloride and phosgene. Reacts violently with powdered aluminium, powdered zinc, aluminium trichloride and ethylene causing fire and explosion hazard. Attacks many metals in the presence of moisture.

OCCUPATIONAL EXPOSURE LIMITS:
TLV: 50 ppm as TWA, 100 ppm as STEL; (skin); A4 (not classifiable as a human carcinogen); (ACGIH 2004).
MAK: 50 ppm 100 mg/m; Peak limitation category: II(2); skin absorption (H); Carcinogen category: 3B; Pregnancy risk group: B; (DFG 2004).
ROUTES OF EXPOSURE:
The substance can be absorbed into the body by inhalation and through the skin.

INHALATION RISK:
A harmful concentration of this gas in the air will be reached very quickly on loss of containment.

EFFECTS OF SHORT-TERM EXPOSURE:
The liquid may cause frostbite. The substance may cause effects on the central nervous system. Exposure may result in unconsciousness. Exposure far above the OEL may result in liver, cardiovascular system and kidney damage. Medical observation is indicated.

EFFECTS OF LONG-TERM OR REPEATED EXPOSURE:
The substance may have effects on the central nervous system, resulting in effects measured using behavioural tests. Animal tests show that this substance possibly causes toxic effects upon human reproduction.
PHYSICAL PROPERTIES
Boiling point: -24.2C
Melting point: -97.6C
Relative density (water = 1): 0.92
Solubility in water, g/100 ml at 25C: 0.5
Vapour pressure, kPa at 21C: 506
Relative vapour density (air = 1): 1.8
Flash point: Flammable Gas
Auto-ignition temperature: 632C
Explosive limits, vol% in air: 8.1-17.4
Octanol/water partition coefficient as log Pow: 0.91
ENVIRONMENTAL DATA

NOTES
Following intoxication patient should be observed carefully for 48 hours. Check oxygen content before entering area. Card has been partly updated in October 2005. See sections Occupational Exposure Limits, Emergency Response.
ADDITIONAL INFORMATION


LEGAL NOTICE Neither the CEC nor the IPCS nor any person acting on behalf of the CEC or the IPCS is responsible for the use which might be made of this information
IPCS, CEC 2005
See Also:
        Methyl chloride (IARC Summary & Evaluation, Volume 71, 1999)
        Methyl chloride (PIM 339)