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METHYL MERCAPTAN ICSC: 0299
Date of Peer Review: May 2003

Methanethiol
Mercaptomethane
Methyl sulfhydrate
Thiomethanol
(cylinder)
CAS # 74-93-1 CH3SH
RTECS # PB4375000 Molecular mass: 48.1
UN # 1064
EC # 016-021-00-3
TYPES OF HAZARD / EXPOSURE ACUTE HAZARDS / SYMPTOMS PREVENTION FIRST AID / FIRE FIGHTING
FIRE Extremely flammable.
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 powder, carbon dioxide.
EXPLOSION Gas/air mixtures are explosive.
Closed system, ventilation, explosion-proof electrical equipment and lighting.
In case of fire: keep cylinder cool by spraying with water.
EXPOSURE
STRICT HYGIENE!

Inhalation Cough. Sore throat. Dizziness. Headache. Nausea. Vomiting. Unconsciousness.
Ventilation, local exhaust, or breathing protection.
Fresh air, rest. Artificial respiration may be needed. Refer for medical attention.
Skin ON CONTACT WITH LIQUID: FROSTBITE.
Cold-insulating gloves.
Remove contaminated clothes. Refer for medical attention. ON FROSTBITE: rinse with plenty of water, do NOT remove clothes.
Eyes Redness. Pain.
Safety goggles, or eye protection in combination with breathing protection.
First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then take to a doctor.
Ingestion


SPILLAGE DISPOSAL PACKAGING & LABELLING
Evacuate danger area! Consult an expert! Ventilation. Do NOT let this chemical enter the environment. (Extra personal protection: self-contained breathing apparatus.)
Marine pollutant.
EU Classification
Symbol: F+, Xn, N
R: 12-20-50/53
S: (2-)-16-25-60-61
UN Classification
UN Hazard Class: 2.3
UN Subsidiary Risks: 2.1

EMERGENCY RESPONSE STORAGE
Transport Emergency Card: TEC (R)-20G2TF
NFPA Code: H 4; F 4; R 0;
Fireproof. Separated from strong oxidants, acids. Cool.
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 1999

SEE IMPORTANT INFORMATION ON BACK


METHYL MERCAPTAN ICSC: 0299
IMPORTANT DATA
PHYSICAL STATE; APPEARANCE:
COLOURLESS GAS, WITH CHARACTERISTIC ODOUR.

PHYSICAL DANGERS:
The gas is heavier than air and may travel along the ground; distant ignition possible.

CHEMICAL DANGERS:
The substance decomposes on burning producing toxic fumes including sulfur oxides and hydrogen sulfide. Reacts violently with strong oxidants. Reacts with water, steam or acids to form flammable and toxic gas.

OCCUPATIONAL EXPOSURE LIMITS:
TLV: 0.5 ppm (ACGIH 2003).
MAK: 0.5 ppm (DFG 2002).
ROUTES OF EXPOSURE:
The substance can be absorbed into the body by inhalation.

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 substance is irritating to the eyes and the respiratory tract. The substance may cause effects on the central nervous system, resulting in respiratory depression. Exposure at high levels may result in unconsciousness. Exposure at high levels may result in death. The effects may be delayed. Medical observation is indicated.

PHYSICAL PROPERTIES
Boiling point: 6C
Melting point: -123C
Relative density (water = 1): 0.9
Solubility in water, g/100 ml at 20C: 2.3
Vapour pressure, kPa at 26.1C: 202
Relative vapour density (air = 1): 1.66
Flash point: Flammable Gas
Explosive limits, vol% in air: 3.9-21.8
ENVIRONMENTAL DATA
The substance is very toxic to aquatic organisms. It is strongly advised that this substance does not enter the environment.
NOTES
Turn leaking cylinder with the leak up to prevent escape of gas in liquid state.
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 1999