Name:
Methanethiol 99.5+%
Synonym:
Thiomethyl Alcohol; Methyl Mercaptan
CAS:
74-93-1
Section 1 - Chemical Product
MSDS Name:Methanethiol 99.5+%
Synonym:Thiomethyl Alcohol; Methyl Mercaptan
Synonym:Thiomethyl Alcohol; Methyl Mercaptan
Section 2 - COMPOSITION, INFORMATION ON INGREDIENTS
| CAS# | Chemical Name | emsds | EINECS# |
| 74-93-1 | Methyl Mercaptan | >99.5 | 200-822-1 |
| Hazard Symbols: XN F+ Risk Phrases: 12 20 |
Section 3 - HAZARDS IDENTIFICATION
EMERGENCY OVERVIEW
Extremely flammable. Harmful by inhalation.
Potential Health Effects
Eye:
Causes eye irritation.
Skin:
Causes skin irritation. May be absorbed through the skin.
Ingestion:
Causes gastrointestinal irritation with nausea, vomiting and diarrhea. May cause liver and kidney damage. May cause central nervous system depression. Mercaptans may cause nausea and headache.
Exposure to high concentrations of mercaptans can produce unconsciousness with cyanosis (bluish discoloration of skin due to deficient oxygenation of the blood), cold extremities and rapid pulse.
Inhalation:
Causes respiratory tract irritation. May cause liver and kidney damage. Exposure produces central nervous system depression. Vapors may cause dizziness or suffocation. Exposure may lead to delirium, convulsions, paralysis, and coma. Exposure to high concentrations of mercaptans can produce unconsciousness with cyanosis (bluish discoloration of skin due to deficient oxygenation of the blood), cold extremities and rapid pulse. Mercaptans may cause nausea and headache. Harmful if inhaled.
Chronic:
May cause liver and kidney damage. Exposure to large doses may cause central nervous system depression.
Extremely flammable. Harmful by inhalation.
Potential Health Effects
Eye:
Causes eye irritation.
Skin:
Causes skin irritation. May be absorbed through the skin.
Ingestion:
Causes gastrointestinal irritation with nausea, vomiting and diarrhea. May cause liver and kidney damage. May cause central nervous system depression. Mercaptans may cause nausea and headache.
Exposure to high concentrations of mercaptans can produce unconsciousness with cyanosis (bluish discoloration of skin due to deficient oxygenation of the blood), cold extremities and rapid pulse.
Inhalation:
Causes respiratory tract irritation. May cause liver and kidney damage. Exposure produces central nervous system depression. Vapors may cause dizziness or suffocation. Exposure may lead to delirium, convulsions, paralysis, and coma. Exposure to high concentrations of mercaptans can produce unconsciousness with cyanosis (bluish discoloration of skin due to deficient oxygenation of the blood), cold extremities and rapid pulse. Mercaptans may cause nausea and headache. Harmful if inhaled.
Chronic:
May cause liver and kidney damage. Exposure to large doses may cause central nervous system depression.
Section 4 - FIRST AID MEASURES
Eyes: Flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids. Get medical aid immediately. Do NOT allow victim to rub eyes or keep eyes closed.
Skin:
Get medical aid. Flush skin with plenty of water for at least 15 minutes while removing contaminated clothing and shoes. Wash clothing before reuse.
Ingestion:
Do not induce vomiting. If victim is conscious and alert, give 2-4 cupfuls of milk or water. Never give anything by mouth to an unconscious person. Get medical aid immediately.
Inhalation:
Get medical aid immediately. Remove from exposure and move to fresh air immediately. If breathing is difficult, give oxygen. Do NOT use mouth-to-mouth resuscitation. If breathing has ceased apply artificial respiration using oxygen and a suitable mechanical device such as a bag and a mask.
Notes to Physician:
Skin:
Get medical aid. Flush skin with plenty of water for at least 15 minutes while removing contaminated clothing and shoes. Wash clothing before reuse.
Ingestion:
Do not induce vomiting. If victim is conscious and alert, give 2-4 cupfuls of milk or water. Never give anything by mouth to an unconscious person. Get medical aid immediately.
Inhalation:
Get medical aid immediately. Remove from exposure and move to fresh air immediately. If breathing is difficult, give oxygen. Do NOT use mouth-to-mouth resuscitation. If breathing has ceased apply artificial respiration using oxygen and a suitable mechanical device such as a bag and a mask.
Notes to Physician:
Section 5 - FIRE FIGHTING MEASURES
General Information:
As in any fire, wear a self-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear. Vapors may form an explosive mixture with air.
Vapors can travel to a source of ignition and flash back. During a fire, irritating and highly toxic gases may be generated by thermal decomposition or combustion. Use water spray to keep fire-exposed containers cool. Extremely flammable liquid and vapor. Containers may explode in the heat of a fire. Will be easily ignited by heat, sparks or flame.
Extinguishing Media:
For small fires, use dry chemical, carbon dioxide, water spray or alcohol-resistant foam. For large fires, use water spray, fog, or alcohol-resistant foam. Use water spray to cool fire-exposed containers. Water may be ineffective. Use agent most appropriate to extinguish fire. Do NOT use straight streams of water.
As in any fire, wear a self-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear. Vapors may form an explosive mixture with air.
Vapors can travel to a source of ignition and flash back. During a fire, irritating and highly toxic gases may be generated by thermal decomposition or combustion. Use water spray to keep fire-exposed containers cool. Extremely flammable liquid and vapor. Containers may explode in the heat of a fire. Will be easily ignited by heat, sparks or flame.
Extinguishing Media:
For small fires, use dry chemical, carbon dioxide, water spray or alcohol-resistant foam. For large fires, use water spray, fog, or alcohol-resistant foam. Use water spray to cool fire-exposed containers. Water may be ineffective. Use agent most appropriate to extinguish fire. Do NOT use straight streams of water.
Section 6 - ACCIDENTAL RELEASE MEASURES
General Information: Use proper personal protective equipment as indicated in Section 8.
Spills/Leaks:
Absorb spill with inert material (e.g. vermiculite, sand or earth), then place in suitable container. Avoid runoff into storm sewers and ditches which lead to waterways. Clean up spills immediately, observing precautions in the Protective Equipment section. Remove all sources of ignition. Use a spark-proof tool. A vapor suppressing foam may be used to reduce vapors. Rinse area for 10 minutes with a strong Sodium Hypochorite (bleach) solution, then reabsorb material.
Spills/Leaks:
Absorb spill with inert material (e.g. vermiculite, sand or earth), then place in suitable container. Avoid runoff into storm sewers and ditches which lead to waterways. Clean up spills immediately, observing precautions in the Protective Equipment section. Remove all sources of ignition. Use a spark-proof tool. A vapor suppressing foam may be used to reduce vapors. Rinse area for 10 minutes with a strong Sodium Hypochorite (bleach) solution, then reabsorb material.
Section 7 - HANDLING and STORAGE
Handling:
Wash thoroughly after handling. Remove contaminated clothing and wash before reuse. Ground and bond containers when transferring material. Avoid contact with eyes, skin, and clothing. Empty containers retain product residue, (liquid and/or vapor), and can be dangerous. Keep away from heat, sparks and flame. Avoid ingestion and inhalation. Do not pressurize, cut, weld, braze, solder, drill, grind, or expose empty containers to heat, sparks or open flames.
Storage:
Keep away from heat, sparks, and flame. Keep away from sources of ignition. Store in a cool, dry place. Keep container closed when not in use. Flammables-area.
Wash thoroughly after handling. Remove contaminated clothing and wash before reuse. Ground and bond containers when transferring material. Avoid contact with eyes, skin, and clothing. Empty containers retain product residue, (liquid and/or vapor), and can be dangerous. Keep away from heat, sparks and flame. Avoid ingestion and inhalation. Do not pressurize, cut, weld, braze, solder, drill, grind, or expose empty containers to heat, sparks or open flames.
Storage:
Keep away from heat, sparks, and flame. Keep away from sources of ignition. Store in a cool, dry place. Keep container closed when not in use. Flammables-area.
Section 8 - EXPOSURE CONTROLS, PERSONAL PROTECTION
Engineering Controls:
Facilities storing or utilizing this material should be equipped with an eyewash facility and a safety shower. Use process enclosure, local exhaust ventilation, or other engineering controls to control airborne levels.
Exposure Limits CAS# 74-93-1: United Kingdom, WEL - TWA: 0.5 ppm TWA; 1.0 mg/m3 TWA United Kingdom, WEL - STEL: 1.5 ppm STEL; 3.0 mg/m3 STEL United States OSHA: ; 10 ppm Ceiling; 20 mg/m3 Ceiling Belgium - TWA: 0.5 ppm VLE; 0.99 mg/m3 VLE France - VME: 0.5 ppm VME; 1 mg/m3 VME Germany: 0.5 ppm TWA; 1 mg/m3 TWA Malaysia: 0.5 ppm TWA; 0.98 mg/m3 TWA Netherlands: 0.5 ppm MAC; 1 mg/m3 MAC Russia: 0.8 mg/m3 TWA Spain: 0.5 ppm VLA-ED; 1 mg/m3 VLA-ED Personal Protective Equipment Eyes: Wear chemical splash goggles. Wear appropriate protective eyeglasses or chemical safety goggles as described by OSHAs eye and face protection regulations in 29 CFR 1910.133 or European Standard EN166.
Skin:
Wear appropriate protective gloves to prevent skin exposure.
Clothing:
Wear appropriate protective clothing to minimize contact with skin.
Respirators:
A respiratory protection program that meets OSHAs 29 CFR 1910.134 and ANSI Z88.2 requirements or European Standard EN 149 must be followed whenever workplace conditions warrant respirator use.
Facilities storing or utilizing this material should be equipped with an eyewash facility and a safety shower. Use process enclosure, local exhaust ventilation, or other engineering controls to control airborne levels.
Exposure Limits CAS# 74-93-1: United Kingdom, WEL - TWA: 0.5 ppm TWA; 1.0 mg/m3 TWA United Kingdom, WEL - STEL: 1.5 ppm STEL; 3.0 mg/m3 STEL United States OSHA: ; 10 ppm Ceiling; 20 mg/m3 Ceiling Belgium - TWA: 0.5 ppm VLE; 0.99 mg/m3 VLE France - VME: 0.5 ppm VME; 1 mg/m3 VME Germany: 0.5 ppm TWA; 1 mg/m3 TWA Malaysia: 0.5 ppm TWA; 0.98 mg/m3 TWA Netherlands: 0.5 ppm MAC; 1 mg/m3 MAC Russia: 0.8 mg/m3 TWA Spain: 0.5 ppm VLA-ED; 1 mg/m3 VLA-ED Personal Protective Equipment Eyes: Wear chemical splash goggles. Wear appropriate protective eyeglasses or chemical safety goggles as described by OSHAs eye and face protection regulations in 29 CFR 1910.133 or European Standard EN166.
Skin:
Wear appropriate protective gloves to prevent skin exposure.
Clothing:
Wear appropriate protective clothing to minimize contact with skin.
Respirators:
A respiratory protection program that meets OSHAs 29 CFR 1910.134 and ANSI Z88.2 requirements or European Standard EN 149 must be followed whenever workplace conditions warrant respirator use.
Section 9 - PHYSICAL AND CHEMICAL PROPERTIES
Physical State: Liquid
Color: water-white - colorless
Odor: garlic-like odor - unpleasant odor
pH: Not available.
Vapor Pressure: 1520 mm Hg @ 26C
Viscosity: Not available.
Boiling Point: 5.95 deg C
Freezing/Melting Point: -123 deg C
Autoignition Temperature: Not available.
Flash Point: >-18 deg C
Explosion Limits, lower: 3.9
Explosion Limits, upper: 21.0
Decomposition Temperature:
Solubility in water: Slightly soluble.
Specific Gravity/Density: .9000g/cm3
Molecular Formula: CH4S
Molecular Weight: 48.11
Section 10 - STABILITY AND REACTIVITY
Chemical Stability:
Stable under normal temperatures and pressures.
Conditions to Avoid:
Incompatible materials, ignition sources, excess heat, strong oxidants.
Incompatibilities with Other Materials:
Strong oxidizing agents, strong reducing agents, strong acids, strong bases, copper, copper alloys, halogenated agents, hydrazine, organic peroxides, zinc, ketones (e.g. acetone, acetophenone, MEK, MIBK), epoxides (e.g. butyl glycidyl ether), lead, moisture, organic materials.
Hazardous Decomposition Products:
Irritating and toxic fumes and gases, sulfur oxides (SOx), including sulfur oxide and sulfur dioxide.
Hazardous Polymerization: Has not been reported
Stable under normal temperatures and pressures.
Conditions to Avoid:
Incompatible materials, ignition sources, excess heat, strong oxidants.
Incompatibilities with Other Materials:
Strong oxidizing agents, strong reducing agents, strong acids, strong bases, copper, copper alloys, halogenated agents, hydrazine, organic peroxides, zinc, ketones (e.g. acetone, acetophenone, MEK, MIBK), epoxides (e.g. butyl glycidyl ether), lead, moisture, organic materials.
Hazardous Decomposition Products:
Irritating and toxic fumes and gases, sulfur oxides (SOx), including sulfur oxide and sulfur dioxide.
Hazardous Polymerization: Has not been reported
Section 11 - TOXICOLOGICAL INFORMATION
RTECS#:
CAS# 74-93-1: PB4375000 LD50/LC50:
CAS# 74-93-1: Inhalation, mouse: LC50 = 6530 ug/m3/2H; Inhalation, rat: LC50 = 675 ppm.
Inhalation, rat: Carcinogenicity:
Methyl Mercaptan - Not listed by ACGIH, IARC, or NTP.
Other:
See actual entry in RTECS for complete information.
CAS# 74-93-1: PB4375000 LD50/LC50:
CAS# 74-93-1: Inhalation, mouse: LC50 = 6530 ug/m3/2H; Inhalation, rat: LC50 = 675 ppm.
Inhalation, rat: Carcinogenicity:
Methyl Mercaptan - Not listed by ACGIH, IARC, or NTP.
Other:
See actual entry in RTECS for complete information.
Section 12 - ECOLOGICAL INFORMATION
Other No information available.
Section 13 - DISPOSAL CONSIDERATIONS
Dispose of in a manner consistent with federal, state, and local regulations.
Section 14 - TRANSPORT INFORMATION
IATA
Not regulated as a hazardous material.
IMO
Not regulated as a hazardous material.
RID/ADR
Not regulated as a hazardous material.
USA RQ: CAS# 74-93-1: 100 lb final RQ; 45.4 kg final RQ
Section 15 - REGULATORY INFORMATION
European/International Regulations
European Labeling in Accordance with EC Directives
Hazard Symbols: XN F+
Risk Phrases:
R 12 Extremely flammable.
R 20 Harmful by inhalation.
Safety Phrases:
S 16 Keep away from sources of ignition - No
smoking.
S 25 Avoid contact with eyes.
WGK (Water Danger/Protection)
CAS# 74-93-1: 3
Canada
CAS# 74-93-1 is listed on Canadas DSL List.
CAS# 74-93-1 is listed on Canadas Ingredient Disclosure List.
US FEDERAL
TSCA
CAS# 74-93-1 is listed on the TSCA inventory.
