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METHYL MERCAPTAN
(cylinder)
ICSC: 0299
Peer-Review Status: 05.06.2003 Validated
Methanethiol
Mercaptomethane
Methyl sulfhydrate
Thiomethanol 
CAS #: 74-93-1 RTECS #: PB4375000
UN #: 1064
EC #: 016-021-00-3
EINECS #: 200-822-1
    Formula: CH3SH
Molecular mass: 48.1

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. Unconciousness.  Use 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.  Wear 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 refer for medical attention. 
Ingestion      

SPILLAGE DISPOSAL
PACKAGING & LABELLING
Evacuate danger area! Consult an expert! Personal protection: self-contained breathing apparatus. Ventilation. Do NOT let this chemical enter the environment.  Marine pollutant. 
EC Classification
Symbol: F+, T, N; R: 12-23-50/53; S: (2)-16-25-60-61 
UN Classification
UN Hazard Class: 2.3; UN Subsidiary Risks: 2.1 
GHS Classification
 

EMERGENCY RESPONSE SAFE STORAGE
Transport Emergency Card: TEC (R)-20G2TF.
NFPA Code: H4; F4; R0. 
Fireproof. Separated from strong oxidants and acids. Cool. Store in an area without drain or sewer access. 

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
Decomposes on burning. This produces toxic fumes including sulfur oxides and hydrogen sulfide. Reacts violently with strong oxidants. Reacts with water, steam and acids. This produces flammable and toxic gas. 

Occupational exposure limits
TLV: 0.5ppm as TWA; (ACGIH 2004).
MAK: 0.5 ppm, 1.0 mg/m³; Peak limitation category: II(2); Pregnancy risk group: D; (DFG 2006). 

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 respiratory tract. The substance may cause effects on the central nervous system. This may result in respiratory depression. Exposure at high levels could cause unconsciousness. Exposure at high levels could cause death. The effects may be delayed. Medical observation is indicated. 

Effects of long-term or repeated exposure
 


PHYSICAL PROPERTIES ENVIRONMENTAL DATA
Boiling point: 6°C
Melting point: -123°C
Relative density (water = 1): 0.9
Solubility in water, g/100ml at 20°C: 2.3
Vapour pressure, kPa at 26.1°C: 202
Relative vapour density (air = 1): 1.66
Flash point: Flammable gas
Explosive limits, vol% in air: 3.9-21.8 
The substance is very toxic to aquatic organisms. It is strongly advised not to let the chemical enter into the environment. 

NOTES
Turn leaking cylinder with the leak up to prevent escape of gas in liquid state.
Card has been partly updated in October 2004.
See sections Occupational Exposure Limits, EU classification, Emergency Response.
Card has been partially updated in July 2007: see Occupational Exposure Limits.
Card has been partially updated in January 2008: see Storage. 

ADDITIONAL INFORMATION
 

IPCS
International
Programme on
Chemical Safety
WHO ILO EC Prepared in the context of cooperation between the International Programme on Chemical Safety and the European Commission
© IPCS 2004-2012
LEGAL NOTICE Neither the EC nor the IPCS nor any person acting on behalf of the EC or the IPCS is responsible for the use which might be made of this information.


    See Also:
       Toxicological Abbreviations
       METHYL MERCAPTAN (JECFA Evaluation)