3D Mol Similar

METHYL MERCAPTAN

: Iupac Name：methanethiol; CAS No.: 74-93-1; Molecular Weight：48.10746; Modify Date.: 2022-11-29 03:20; Introduction: Methanethiol (also known as methyl mercaptan) is a colorless gas with a smell like rotten cabbage. It is a natural substance found in the blood and brain of humans and other animals as well as plant tissues. It is disposed of through animal feces. It occurs naturally in certain foods, such as some nuts and cheese. It is also one of the main chemicals responsible for bad breath and the smell of flatus. The chemical formula for methanethiol is CH3SH; it is classified as a thiol. It is sometimes abbreviated as MeSH. It is very flammable. View more+

Request For Quotation

1. Names and Identifiers

: 1.1 Name; METHYL MERCAPTAN; 1.2 Synonyms; 4Q 1998 CH3SH EINECS 200-822-1 FEMA 2716 MERCAPTAN C1 MERCAPTOMETHYLE Methaanthiol Methanethiole methanethiolvialwith25ml Methanthiol Methvtiolo methyl mercaptane Methyl thioalcohol methylenethiol Methylmercaptaan methylmercaptan methylthioalcohol Metilmercaptano MFCD00004866 THIOMETHANOL; View all

1.3 CAS No.: 74-93-1

1.4 CID: 878

1.5 EINECS(EC#): 200-822-1

1.6 Molecular Formula: CH4S (isomer)

1.7 Inchi: InChI=1S/CH4S/c1-2/h2H,1H3

1.8 InChIkey: LSDPWZHWYPCBBB-UHFFFAOYSA-N

1.9 Canonical Smiles: CS

1.10 Isomers Smiles: CS

2. Properties

2.1 Density: 0.8665

2.1 Melting point: -121~-123℃

2.1 Boiling point: 6℃

2.1 Refractive index: 1.430-1.436 (gas); 0.894 (liquid)

2.1 Flash Point: <71℃

2.2 Precise Quality: 48.00340

2.2 PSA: 38.80000

2.2 logP: 0.54600

2.2 VaporDensity: 1.66 (vs air)

2.3 Appearance: Methyl mercaptan appears as a colorless low-boiling liquid that is denser than water. Very toxic by inhalation. Can be absorbed through the skin. Has a sharp odor, but the sense of smell cannot be relied upon to warn of the presence of vapors at low concentrations. Rate of onset: Immediate Persistence: Minutes to hours Odor threshold: 0.002 ppm Source/use/other hazard: From decayed organic matter - pulp mills, oil refineries; highly flammable; liquid burns/frostbite.

2.4 Atmospheric OH Rate Constant: 3.29e-11 cm3/molecule*sec

2.5 Chemical Properties: colourless gas with a garlic-like or rotten cabbage-like smell

2.6 Color/Form: Water-white liq when below boiling point, or colorless gas

2.7 Decomposition: Upon decomposition, emits highly toxic fumes of /sulfur oxides/.

2.8 Heat of Combustion: -11,054 Btu/lb = -6,141 cal/g = -257.0x10+5 J/kg

2.9 Heat of Vaporization: 510.21 kJ/kg

2.10 Ionization Potential: 9.44 eV

2.11 Odor: Odor of rotten cabbage

2.12 Odor Threshold: 0.0021 ppm (purity not specified)

2.13 pKa: 10.3(at 25℃)

2.14 Water Solubility: 23.30 g/L at 20 °C (quoted, Windholz et al., 1983) 0.330 mol/L at 25 °C (Hine and Weimar, 1965)

2.15 Spectral Properties: MAX ABSORPTION (CYCLOHEXANE): 228.5 NM (LOG E= 2.15)
IR: 17224 (Sadtler Research Laboratories IR Grating Collection)
UV: 3-1 (Organic Electronic Spectral Data, Phillips et al, John Wiley & Sons, New York)
NMR: 8209 (Sadtler Research Laboratories Prism Collection)
MASS: 86 (NIST/EPA/MSDC Mass Spectral Database 1990 Version); 266 (Atlas of Mass Spectral Data, John Wiley and Sons, NY)

2.16 Stability: Stable. Highly flammable - note low flash point. Reacts vigorously or explosively with a wide variety of materials - consult a full MSDS data sheet before using. Incompatible with strong oxidizing agents, alkali and alkaline earth metals, epoxides, hydrazines, ketones, lead, mercury (II) oxide, azo- and diazo- compounds, copp

2.17 Surface Tension: 31 dynes/cm = 0.031 N/m at 5 °C

3. Use and Manufacturing

3.1 Methods of Manufacturing: e preparation method is to put water and thiourea into the reaction kettle, add dimethyl sulfate dropwise, when the temperature naturally rises to 80～90℃, start to heat to 116～120℃, react for 30～40min, discharge, cool and centrifuge , The filter cake is methyl isothiourea sulfate, and then lye is added dropwise to methyl isothiourea sulfate at 80° C., and methyl mercaptan is continuously produced. Methyl mercaptan can also be obtained by reacting methyl chloride and sodium hydrosulfide. Add 36% sodium hydrosulfide into the autoclave, press nitrogen into the methyl chloride, start stirring, control the temperature not to exceed 100°C and the pressure not to exceed 1.7 MPa, and react For 30 minutes, when the temperature and pressure drop to a moderate level, open the pressure valve, control the pressure and flow, and obtain sodium methyl mercaptan after washing and absorption. CH3Cl+NaHS[Pressure]→CH3SH+NaClCH3SH+NaOH→CH3SNa+H2O

3.2 Potential Exposure: Methyl mercaptan is used in methionine synthesis, and widely as an intermediate in pesticidemanufacture. A foul-smelling odorant usually added tochemicals, including pesticides.

3.3 Shipping: UN1064 Methyl mercaptan, Hazard Class: 2.3;Labels: 2.3-Poisonous gas, 2.1-Flammable gas, InhalationHazard Zone C. Cylinders must be transported in a secureupright position, in a well-ventilated truck. Protect cylinderand labels from physical damage. The owner of the compressed gas cylinder is the only entity allowed by federallaw (49CFR) to transport and refill them. It is a violationof transportation regulations to refill compressed gas cylinders without the express written permission of the owner.

3.4 Usage: Methanethiol is mainly used to produce methionine, which is used as a dietary component in poultry and animal feed. Methanethiol is also used in the plastics industry and as a precursor in the manufacture of pesticides. It is released as a by-product of wood pulping in pulp mills. Methanethiol is also used for communication in mining operations . Releasing the substance into the ventilation system is generally the most efficient and reliable means to alert all workers of an emergency , and is referred to as "releasing the pest" ,This substance's strong odor alerts the miners to immediately go to a saferoom. Since natural gas and propane are colorless and odorless, a small amount of methyl mercaptan or ethyl mercaptan is added to make it easy to detect a gas leak.

4. Safety and Handling

4.1 Hazard Codes: F+; T; N

4.1 Risk Statements: R12

4.1 Safety Statements: 16-25-60-61

4.1 Exposure Standards and Regulations: Methyl mercaptan is a food additive permitted for direct addition to food for human consumption as a synthetic flavoring substance and adjuvant in accordance with the following conditions: a) they are used in the minimum quantity required to produce their intended effect, and otherwise in accordance with all the principles of good manufacturing practice, and 2) they consist of one or more of the following, used alone or in combination with flavoring substances and adjuvants generally recognized as safe in food, prior-sanctioned for such use, or regulated by an appropriate section in this part.

4.2 Packing Group: O52

4.2 Octanol/Water Partition Coefficient: log Kow = 0.65 [Abraham MH et al; J Pharm Sci 83:1085-100 (1994)] PubMed Abstract

4.3 Fire Hazard: Combustion produces irritating sulfur dioxide. Flash back along vapor track may occur. Very dangerous when exposed to heat, flame, or oxidizers. On decomposition METHYL MERCAPTAN emits highly toxic fumes of sulfur oxides. METHYL MERCAPTAN will react with water, steam or acids to produce toxic and flammable vapors; and can react vigorously with oxidizing materials. Irritating sulfur dioxide is produced upon combustion. When heated to decomposition, METHYL MERCAPTAN emits highly toxic fumes and flammable vapors. Incompatible with mercuric oxide and oxidizing materials. Avoid direct sunlight, and areas of high fire hazards. Hazardous polymerization may not occur.

4.4 Other Preventative Measures: Open flames and other ignition sources should be excluded from areas where thiols, especially the more volatile ones, are used. Emergency procedures and routine work practices should emphasize proper handling, containment of spills ... . The primary purpose of control measures is to reduce the potential for inhalation or skin contact with thiols, with special emphasis on the eyes. Whenever feasible, control at the source of exposure should be implemented. This may involve enclosure of the operation and/or the use of local exhaust ventilation. /Thiols/
Safety showers, eye wash fountains and fire extinguishers should be located in areas where appreciable amounts of thiols are used. Handwashing facilities, soap and water, should be made available to involved employees. /Thiols/
Clothing which is contaminated with methyl mercaptan should be removed immediately and placed in closed containers for storage until it can be discarded or until a provision is made for the removal of methyl mercaptan from the clothing. If the clothing is to be laundered or cleaned, the person performing the operation should be informed of methyl mercaptan's hazardous properties.
Change and shower rooms should be provided with separate locker facilities for street and work clothes.
Respiratior Recommendations: Escape: (Assigned protection factor = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted organic vapor canister/Any appropriate escape-type, self-contained breathing apparatus.
The storage, preparation, dispensing, or consumption of food or beverages, the storage or application of cosmetics, the storage or smoking of tobacco or other smoking materials, or the storage or use of products for chewing should be prohibited in work areas.
Workers who handle methyl mercaptan should wash their faces, hands, and forearms thoroughly with soap and water before eating, smoking, or using toilet facilities.
Work clothing that becomes wet should be immediately removed due to its flammability hazard (i.e., for liquids with a flash point less than 100 deg F).
SRP: The scientific literature for the use of contact lenses in industry is conflicting. The benefit or detrimental effects of wearing contact lenses depend not only upon the substance, but also on factors including the form of the substance, characteristics and duration of the exposure, the uses of other eye protection equipment, and the hygiene of the lenses. However, there may be individual substances whose irritating or corrosive properties are such that the wearing of contact lenses would be harmful to the eye. In those specific cases, contact lenses should not be worn. In any event, the usual eye protection equipment should be worn even when contact lenses are in place.; View all

4.5 Hazard Class: 2.3

4.5 Hazard Declaration: H220

4.5 Cleanup Methods: Spills of thiols can be neutralized with a household bleach solution and flushed with an abundant flow of water. /Thiols/
A variety of methods and procedures, and also patents, are available with methods to absorb odors in scrubbers, by use of catalytic oxidizers or combined scrubber systems with oxidizing agents such as ozone or peroxides. /methyl mercaptans/
If methyl mercaptan is spilled or leaked, the following steps should be taken: 1. If methyl mercaptan is in the gaseous form, stop the flow of gas. If the source of the leak is a cylinder and the leak cannot be stopped in place, remove the leaking cylinder to a safe place in the open air and repair the leak or allow the cylinder to empty. 2. Remove all ignition sources. 3. Ventilate area of spill or leak. 4. For small quantities of liquids containing methyl mercaptan, absorb on paper towels and place in an appropriate container. Place towels in a safe place such as a fume hood for evaporation. Allow sufficient time for evaporation of the vapors so that the hood duct work is free from methyl mercaptan vapors. Burn the paper in a suitable location away from combustible material. 5. Large quantities of liquids containing methyl mercaptan may be absorbed in vermiculite, dry sand, earth, or a similar material and placed in an appropriate container. Methyl mercaptan should not be allowed to enter a confined space such as a sewer because of the possibility of an explosion. 6. Liquids containing methyl mercaptan may be collected by vacuuming with an appropriate system. If a vacuum system is used, there should be no sources of ignition in the vicinity of the spill, and flashback prevention devices should be provided.; View all

4.6 DisposalMethods: Generators of waste (equal to or greater than 100 kg/mo) containing this contaminant, EPA hazardous waste number U153, must conform with USEPA regulations in storage, transportation, treatment and disposal of waste.
Methyl mercaptan is a waste chemical stream constituent that may be subjected to ultimate disposal by controlled incineration, followed by effective scrubbing of the effluent gas.
A potential candidate for fluidized bed incineration at a temperature range of 450 to 980 deg C and residence times of seconds for liquids and gases, and longer for solids. A potential candidate for rotary kiln incineration at a temperature range of 820 to 1,600 deg C and residence times of seconds for liquids and gases, and hours for solids.

4.7 DOT Emergency Guidelines: If ... THERE IS NO FIRE, go directly to the Table of Initial Isolation and Protective Action Distances /(see table below)/ ... to obtain initial isolation and protective action distances. IF THERE IS A FIRE, or IF A FIRE IS INVOLVED, go directly to the appropriate guide /(see guide(s) below)/ and use the evacuation information shown under PUBLIC SAFETY. Table of Initial Isolation and Protective Action Distances for Methyl mercaptan Small Spills (from a small package or small leak from a large package) -------------------- First ISOLATE in all Directions 30 meters (100 feet) Then PROTECT persons Downwind during DAY: 0.1 kilometers (0.1 miles) Then PROTECT persons Downwind during NIGHT: 0.2 kilometers (0.2 miles) ==================== Large Spills (from a large package or from many small packages) -------------------- First ISOLATE in all Directions 150 meters (500 feet) Then PROTECT persons Downwind during DAY: 1.3 kilometers (0.8 miles) Then PROTECT persons Downwind during NIGHT: 4.5 kilometers (2.8 miles)
/GUIDE 117: GASES - TOXIC - FLAMMABLE (EXTREME HAZARD)/ Health: TOXIC; Extremely Hazardous. May be fatal if inhaled or absorbed through skin. Initial odor may be irritating or foul and may deaden your sense of smell. Contact with gas or liquefied gas may cause burns, severe injury and/or frostbite. Fire will produce irritating, corrosive and/or toxic gases. Runoff from fire control may cause pollution.
/GUIDE 117: GASES - TOXIC - FLAMMABLE (EXTREME HAZARD)/ Fire or Explosion: These materials are extremely flammable. May form explosive mixtures with air. May be ignited by heat, sparks or flames. Vapors from liquefied gas are initially heavier than air and spread along ground. Vapors may travel to source of ignition and flash back. Runoff may create fire or explosion hazard. Cylinders exposed to fire may vent and release toxic and flammable gas through pressure relief devices. Containers may explode when heated. Ruptured cylinders may rocket.
/GUIDE 117: GASES - TOXIC - FLAMMABLE (EXTREME HAZARD)/ Public Safety: CALL Emergency Response Telephone Number ... . As an immediate precautionary measure, isolate spill or leak area for at least 100 meters (330 feet) in all directions. Keep unauthorized personnel away. Stay upwind. Many gases are heavier than air and will spread along ground and collect in low or confined areas (sewers, basements, tanks). Keep out of low areas. Ventilate closed spaces before entering.
/GUIDE 117: GASES - TOXIC - FLAMMABLE (EXTREME HAZARD)/ Protective Clothing: Wear positive pressure self-contained breathing apparatus (SCBA). Wear chemical protective clothing that is specifically recommended by the manufacturer. It may provide little or no thermal protection. Structural firefighters' protective clothing provides limited protection in fire situations ONLY; it is not effective in spill situations where direct contact with the substance is possible.
/GUIDE 117: GASES - TOXIC - FLAMMABLE (EXTREME HAZARD)/ Evacuation: ... Fire: If tank, rail car or tank truck is involved in a fire, ISOLATE for 1600 meters (1 mile) in all directions; also, consider initial evacuation for 1600 meters (1 mile) in all directions.
/GUIDE 117: GASES - TOXIC - FLAMMABLE (EXTREME HAZARD)/ Fire: DO NOT EXTINGUISH A LEAKING GAS FIRE UNLESS LEAK CAN BE STOPPED. Small fires: Dry chemical, CO2, water spray or regular foam. Large fires: Water spray, fog or regular foam. Move containers from fire area if you can do it without risk. Damaged cylinders should be handled only by specialists. Fire involving tanks: Fight fire from maximum distance or use unmanned hose holders or monitor nozzles. Cool containers with flooding quantities of water until well after fire is out. Do not direct water at source of leak or safety devices; icing may occur. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank. ALWAYS stay away from tanks engulfed in fire.
/GUIDE 117: GASES - TOXIC - FLAMMABLE (EXTREME HAZARD)/ Spill or Leak: ELIMINATE all ignition sources (no smoking, flares, sparks or flames in immediate area). All equipment used when handling the product must be grounded. Fully encapsulating, vapor protective clothing should be worn for spills and leaks with no fire. Do not touch or walk through spilled material. Stop leak if you can do it without risk. Use water spray to reduce vapors or divert vapor cloud drift. Avoid allowing water runoff to contact spilled material. Do not direct water at spill or source of leak. If possible, turn leaking containers so that gas escapes rather than liquid. Prevent entry into waterways, sewers, basements or confined areas. Isolate area until gas has dispersed. Consider igniting spill or leak to eliminate toxic gas concerns.
/GUIDE 117: GASES - TOXIC - FLAMMABLE (EXTREME HAZARD)/ First Aid: Move victim to fresh air. Call 911 or emergency medical service. Give artificial respiration if victim is not breathing. Do not use mouth-to-mouth method if victim ingested or inhaled the substance give artificial respiration with the aid of a pocket mask equipped with a one-way valve or other proper respiratory medical device. Administer oxygen if breathing is difficult. Remove and isolate contaminated clothing and shoes. In case of contact with substance, immediately flush skin or eyes with running water for at least 20 minutes. In case of contact with liquefied gas, thaw frosted parts with lukewarm water. In case of burns, immediately cool affected skin for as long as possible with cold water. Do not remove clothing if adhering to skin. Keep victim warm and quiet. Keep victim under observation. Effects of contact or inhalation may be delayed. Ensure that medical personnel are aware of the material(s) involved and take precautions to protect themselves.; View all

4.8 RIDADR: UN 2037 2.3

4.8 Fire Fighting Procedures: Preferably let fire burn, stop gas flow. Fires may be extinguished with dry chemical, foam, or carbon dioxide. Water may be ineffective.
To fight fire: Alcohol foam, carbon dioxide, dry chemical.

4.9 FirePotential: Very dangerous, when exposed to heat, flame or oxidizers.

4.10 Safety Profile: Poison by inhalation.Mutation data reported. A common aircontaminant. Very dangerous fire hazardwhen exposed to heat or flame; can reactvigorously with oxidzing materials.Explosive in the form of vapor whenexposed to heat or flame. Reacts with water,steam, or acids to produce toxic andflammable vapors. Violent reaction withmercury(II) oxide. To fight fire, use alcoholfoam, CO2, dry chemical. Upondecomposition it emits highly toxic fumes ofSOx.

4.11 Caution Statement: P210, P261, P271, P273, P304+P340, P311, P321, P377, P381, P391, P403, P403+P233, P405, P501

4.11 Formulations/Preparations: 98% pure
99.5% pure minimum grade /Matheson Gas Products/

4.12 Incompatibilities: Violent reaction with strong oxidizers,bleaches, copper, nickel and their alloys; aluminum. Reactswith acids producing flammable and toxic hydrogensulfide

4.13 WGK Germany: 3

4.13 RTECS: PB4375000

4.13 Protective Equipment and Clothing: Respirator Recommendations: Up to 5 ppm: (Assigned protection factor = 10) Any chemical cartridge respirator with organic vapor cartridge(s)/(Assigned protection factor = 10) Any supplied-air respirator.
Respirator Recommendations: Up to 12.5 ppm: (Assigned protection factor = 25) Any supplied-air respirator operated in a continuous flow mode/(Assigned protection factor = 25) Any powered, air-purifying respirator with organic vapor cartridge(s).
Respirator Recommendations: Up to 25 ppm: (Assigned protection factor = 50) Any chemical cartridge respirator with a full facepiece and organic vapor cartridge(s)/ (Assigned protection factor = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted organic vapor canister/ Assigned protection factor = 50) Any powered, air-purifying respirator with a tight-fitting facepiece and organic vapor cartridge(s)/ (Assigned protection factor = 50) Any supplied-air respirator that has a tight-fitting facepiece and is operated in a continuous-flow mode/ (Assigned protection factor = 50) Any supplied-air respirator with a full facepiece.
Respirator Recommendations: Up to 150 ppm: (Assigned protection factor = 1000) Any supplied-air respirator operated in a pressure-demand or other positive-pressure mode.
Respirator Recommendations: Emergency or planned entry into unknown concentrations or IDLH conditions: (Assigned protection factor = 10,000) Any self-contained breathing apparatus that has a full facepiece and is operated in a pressure-demand or other positive pressure mode/ (Assigned protection factor = 10,000) Any supplied-air respirator with a full facepiece and operated in pressure-demand or other positive pressure mode in combination with an auxiliary self-contained positive-pressure breathing apparatus.
Recommendations for respirator selection. Condition: Escape from suddenly occurring respiratory hazards: Respirator Classes: Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted organic vapor canister. Any appropriate escape-type, self-contained breathing apparatus.
It is recommended that methanethiol be handled with caution above the TLV, using safety glasses, protective gloves, and respiratory equipment.
Where ... engineering controls are not sufficient to reduce airborne concentrations to acceptable levels, respirators may be necessary to prevent pulmonary irritation and systemic effects. At low concentrations (less than 5 ppm) a chemical cartridge respirator with a half-mask facepiece and organic vapor cartridges can be used. At high concentrations, supplied air respirators, with a full facepiece, are necessary. /Thiols/
Chemical protective clothing should be selected after utilizing available performance data, consulting with the manufacturer, and then evaluating the clothing under actual use conditions. Workers should be provided with and required to use chemical protective clothing, gloves, face shield (8-inch minimum), and other appropriate protective clothing necessary to prevent skin contact with methyl mercaptan. Workers should be provided with and required to use splashproof safety goggles where methyl mercaptan may come in contact with the eyes.
Wear appropriate personal protective clothing to prevent skin contact. /Liquid/
Wear appropriate personal protective clothing to prevent the skin from becoming frozen from contact with the liquid or from contact with vessels containing the liquid.
Wear appropriate eye protection to prevent eye contact. /Liquid/
Wear appropriate eye protection to prevent eye contact with the liquid that could result in burns or tissue damage from frostbite.
Facilities for quickly drenching the body should be provided within the immediate work area for emergency use where there is a possibility of exposure. [Note: It is intended that these facilities should provide a sufficient quantity or flow of water to quickly remove the substance from any body areas likely to be exposed. The actual determination of what constitutes an adequate quick drench facility depends on the specific circumstances. In certain instances, a deluge shower should be readily available, whereas in others, the availability of water from a sink or hose could be considered adequate.] /Liquid/
Eyewash fountains should be provided in areas where there is any possbility that workers could be exposed to the substance; this is irrespective of the recommendation involving the wearing of eye protection. /Liquid/
Facilities for quickly drenching the body should be provided within the immediate work area for emergency use where there is a possibility of exposure. [Note: It is intended that these facilities provide a sufficient quantity or flow of water to quickly remove the substance from any body areas likely to be exposed. The actual determination of what constitutes an adequate quick drench facility depends on the specific circumstances. In certain instances, a deluge shower should be readily available, whereas in others, the availability of water from a sink or hose could be considered adequate.] /Liquid/; View all

4.14 Reactivities and Incompatibilities: Strong oxidizers, bleaches, copper, aluminum, nickel-copper alloys.
Incompatible /with/ mercury (II) oxide.

4.15 Skin, Eye, and Respiratory Irritations: ... Contact with the liquid or vapor may cause irritation of the skin, eyes and mucous membranes of the upper resp tract. /Thiols/
... Direct contact with liquid may cause frostbite.

4.16 Safety: Poison by inhalation. Mutation data reported. A common air contaminant. Very dangerous fire hazard when exposed to heat or flame; can react vigorously with oxidizing materials. Explosive in the form of vapor when exposed to heat or flame. Reacts with water, steam, or acids to produce toxic and flammable vapors. Violent reaction with mercury(II) oxide. To fight fire, use alcohol foam, CO2, dry chemical. Upon decomposition it emits highly toxic fumes of SOx. See also MERCAPTANS.Analytical Methods: For occupational chemical analysis use OSHA: #26.

4.17 Specification: colourless gas with a garlic-like or rotten cabbage-like smell
Safety Statements:16-25-60-61
16:Keep away from sources of ignition - No smoking
25:Avoid contact with eyes
60:This material and/or its container must be disposed of as hazardous waste
61:Avoid release to the environment. Refer to special instructions safety data sheet

4.18 Toxicity: Inhalation-Rat LC50: 675 PPM; Inhalation-Mouse 6.53 mg/m3/ 2 hours

5. MSDS

2.Hazard identification

2.1 Classification of the substance or mixture

Gases under pressure: Compressed gas

Flammable gases, Category 1

Acute toxicity - Inhalation, Category 3

Hazardous to the aquatic environment, short-term (Acute) - Category Acute 1

Hazardous to the aquatic environment, long-term (Chronic) - Category Chronic 1

2.2 GHS label elements, including precautionary statements

Pictogram(s)
Signal word	Danger
Hazard statement(s)	H220 Extremely flammable gas H331 Toxic if inhaled H410 Very toxic to aquatic life with long lasting effects
Precautionary statement(s)
Prevention	P210 Keep away from heat, hot surfaces, sparks, open flames and other ignition sources. No smoking. P261 Avoid breathing dust/fume/gas/mist/vapours/spray. P271 Use only outdoors or in a well-ventilated area. P273 Avoid release to the environment.
Response	P377 Leaking gas fire: Do not extinguish, unless leak can be stopped safely. P381 In case of leakage, eliminate all ignition sources. P304+P340 IF INHALED: Remove person to fresh air and keep comfortable for breathing. P311 Call a POISON CENTER/doctor/\u2026 P321 Specific treatment (see ... on this label). P391 Collect spillage.
Storage	P410+P403 Protect from sunlight. Store in a well-ventilated place. P403 Store in a well-ventilated place. P403+P233 Store in a well-ventilated place. Keep container tightly closed. P405 Store locked up.
Disposal	P501 Dispose of contents/container to ...

2.3 Other hazards which do not result in classification

none

View all

6. NMR Spectrum

1H NMR : parameter in benzene

7. Synthesis Route

74-93-1Total: 233 Synthesis Route

67-56-1 382 Suppliers

74-93-1 39 Suppliers

Literatures:
Redlingshoefer, Hubert; Weckbecker, Christoph Patent: US2008/15390 A1, 2008 ; Location in patent: Page/Page column 5 ;
Yield: ~93%

75-18-3 132 Suppliers

74-93-1 39 Suppliers

Literatures:
US2822400 , ; US2822401 , ; US2820061 , ; US2820062 , ; US2819313 , ; US2820060 , ; US2816146 , ; US2820831 , ; US2796438 , ; US2786079 , ; US2667515 , ;
Yield: ~%

75-15-0 112 Suppliers

74-93-1 39 Suppliers

Literatures:
US2565195 , ;
Yield: ~%

View all

8. Precursor and Product

precursor:

5416-30-8

556-64-9

75-18-3

67-68-5

103-72-0

834-12-8

75-15-0

6156-18-9

67-56-1

74-87-3

124-38-9

624-92-0

507-09-5

917-64-6

56-89-3

View all

product :

5188-07-8

29878-05-5

17302-63-5

373-80-8

1534-08-3

5756-24-1

19163-05-4

630-19-3

54187-93-8

87424-25-7

3658-80-8

22015-54-9

16978-68-0

7022-45-9

30009-65-5

75-75-2

2687-50-5

2523-90-2

18542-42-2

30411-03-1

20901-21-7

861527-45-9

7330-31-6

997-49-9

17032-46-1

View all

9. Other Information

9.0 Merck: 13,5983

9.1 BRN: 1696840

9.2 Description: Methanethiol (also known as methyl mercaptan) is a colorless gas with a smell like rotten cabbage. It is a natural substance found in the blood and brain of humans and other animals as well as plant tissues. It is disposed of through animal feces. It occurs naturally in certain foods, such as some nuts and cheese. It is also one of the main chemicals responsible for bad breath and the smell of flatus. The chemical formula for methanethiol is CH₃SH; it is classified as a thiol. It is sometimes abbreviated as MeSH. It is very flammable.

9.3 Chemical Properties: colourless gas with a garlic-like or rotten cabbage-like smell

9.4 Chemical Properties: Methyl mercaptan is a colorless gas or white liquid with a disagreeable odor like garlic or rotten cabbage. Shipped as a liquefied compressed gas. The odor threshold is 0.002 ppm.

9.5 Chemical Properties: Methyl mercaptan has an objectionable odor of decomposing cabbage. May be prepared by heating an aqueous solution of potassium methyl sulfate and KHS; from sodium methyl sulfate and potassium sulfhydrate; also from methanol and hydrogen sulfide in the presence of a catalyst.

9.6 Chemical Properties: Methyl mercaptan has an objectionable odor of decomposing cabbage or garlic

9.7 Physical properties: Colorless gas with a garlic-like or rotten cabbage odor. An experimentally determined odor threshold concentration of 2.1 ppb_v was reported by Leonardos et al. (1969). A detection odor threshold concentration of 81 μg/m³ (41 ppb_v) was determined by Katz and Talbert (1930).

9.8 Occurrence: Methanethiol is released from decaying organic matter in marshes and is present in the natural gas of certain regions, in coal tar, and in some crude oils.
In surface seawater, methanethiol is the primary breakdown product of the algal metabolite dimethylsulfoniopropionate (DMSP). Marine bacteria appear to obtain most of their protein sulfur by the breakdown of DMSP and incorporation of methanethiol, despite the fact that methanethiol is present in seawater at much lower concentrations than sulfate (～0.3 nM vs. 28 mM). Bacteria in oxic and anoxic environments can also convert methanethiol to dimethyl sulfide (DMS), although most DMS in surface seawater is produced by a separate pathway. Both DMS and methanethiol can be used by certain microbes as substrates for methanogenesis in some anaerobic soils.
Methanethiol is a weak acid, with a pKa of ～10.4. This acidic property makes it reactive with dissolved metals in aqueous solutions. The environmental chemistry of these interactions in seawater or fresh water environments such as lakes has yet to be fully investigated.
A material safety data sheet (MSDS) lists methanethiol as a colorless, flammable gas with an extremely strong and repulsive smell. At very high concentrations it is highly toxic and affects the central nervous system. Its penetrating odor provides warning at dangerous concentrations. An odor threshold of 1 ppb has been reported. The United States OSHA Ceiling Limit is listed as 10 ppm.; View all

9.9 Uses: Methanethiol is mainly used to produce methionine, which is used as a dietary component in poultry and animal feed. Methanethiol is also used in the plastics industry and as a precursor in the manufacture of pesticides. It is released as a by-product of wood pulping in pulp mills.
Methanethiol is also used for communication in mining operations . Releasing the substance into the ventilation system is generally the most efficient and reliable means to alert all workers of an emergency , and is referred to as "releasing the pest" ,This substance's strong odor alerts the miners to immediately go to a saferoom.
Since natural gas and propane are colorless and odorless, a small amount of methyl mercaptan or ethyl mercaptan is added to make it easy to detect a gas leak.

9.10 Uses: Methanethiol is used in the manufacture ofpesticides and fungicides and as an intermediate in the manufacture of jet fuels (Watkinset al. 1989); it is added to natural gas to giveodor. It is used in the synthesis of methionine.

9.11 Uses: Methanethiol is an Intermediate in manufacturing of jet fuels, pesticides, fungicides, plastics; synthesis of methionine; emission from paper pulp mills, odoriferous additive to natural gas.

9.12 Preparation: Methanethiol is prepared commercially by the reaction of methanol with hydrogen sulfide gas over an acidic solid catalyst, such as alumina. It can be prepared by the reaction of methyl iodide with thiourea.

9.13 Aroma threshold values: Detection: 0.02 to 4 ppb. Aroma characteristics at 1.0%: vegetable oil, alliaceous, eggy, creamy with savory nuances

9.14 Taste threshold values: Taste characteristics at 1 ppm: sulfurous, alliaceous, creamy with a surface-ripened cheese top note and a clean, savory, meaty depth

9.15 Air & Water Reactions: Highly flammable. Reacts with water, steam or acids to produce toxic, flammable vapors [Lewis].

9.16 Reactivity Profile: METHYL MERCAPTAN is a reducing agent--can react vigorously with oxidizing agents. Dangerous fire or explosion hazard when exposed to heat, flame, sparks or strong oxidizing agents (e.g., calcium hypochlorite). When heating to decomposition emits highly toxic fumes of oxides of sulfur [Lewis, 3rd ed., 1993, p. 862]. Violent reaction with mercury(II) oxide [Klason P., Ber., 1887, 20, p. 3410].

9.17 Hazard: Flammable, dangerous fire risk. Explosive limits in air 3.9–21.8%. Strong irritant. Liver damage.

9.18 Health Hazard: Can cause death by respiratory paralysis. It is an eye and respiratory tract irritant. Exposure results in pulmonary edema and hepatic and renal damage.

9.19 Health Hazard: The acute toxicity of methanethiol is simi-lar to that of hydrogen sulfide. Inhalation ofthis gas can cause narcosis, headache, nau-sea, pulmonary irritation, and convulsions inhumans. Other symptoms noted are acutehemolytic anemia, methemoglobinemia, andcyanosis. In humans, several hours exposure to about 5 ppm concentration of thisgas can cause headache and nausea. Exposure to high concentrations can result inrespiratory paralysis and death. The 2-hour inhalation LC50 value in mice is within therange 650 mg/m³.
Shults et al. (1970) reported a case of ahuman death from overexposure to methane-thiol. The victim developed acute hemolyticanemia and methemoglobinemia and re-mainedindeepcomauntil deaththatoccurred28 days after the accident from emptying gascylinders.

9.20 Fire Hazard: Combustion produces irritating sulfur dioxide. Flash back along vapor track may occur. Very dangerous when exposed to heat, flame, or oxidizers. On decomposition METHYL MERCAPTAN emits highly toxic fumes of sulfur oxides. METHYL MERCAPTAN will react with water, steam or acids to produce toxic and flammable vapors; and can react vigorously with oxidizing materials. Irritating sulfur dioxide is produced upon combustion. When heated to decomposition, METHYL MERCAPTAN emits highly toxic fumes and flammable vapors. Incompatible with mercuric oxide and oxidizing materials. Avoid direct sunlight, and areas of high fire hazards. Hazardous polymerization may not occur.

9.21 Safety Profile: Poison by inhalation. Mutation data reported. A common air contaminant. Very dangerous fire hazard when exposed to heat or flame; can react vigorously with oxidzing materials. Explosive in the form of vapor when exposed to heat or flame. Reacts with water, steam, or acids to produce toxic and flammable vapors. Violent reaction with mercury(II) oxide. To fight fire, use alcohol foam, CO2, dry chemical. Upon decomposition it emits highly toxic fumes of SOx.

9.22 Chemical Synthesis: By heating an aqueous solution of potassium methyl sulfate and KHS; from sodium methyl sulfate and potassium sulfhydrate; also from methanol and hydrogen sulfide in the presence of a catalyst

9.23 Potential Exposure: Methyl mercaptan is used in methionine synthesis, and widely as an intermediate in pesticide manufacture. A foul-smelling odorant usually added to chemicals, including pesticides.

9.24 Source: Occurs naturally in kohlrabi stems (Brassica oleracea var. gongylodes) and potato plants (Duke, 1992)

9.25 Environmental fate: Biological. After 20 d, methyl mercaptan started to degrade in anaerobic sediments and sludges producing stoichiometric amounts of methane. Complete degradation was achieved after 20 d. Under anaerobic freshwater conditions, methyl mercaptan were degraded by methanogenic archea (van Leerdam et al., 2006).
Photolytic. Sunlight irradiation of a methyl mercaptan-nitrogen oxide mixture in an outdoor chamber yielded formaldehyde, sulfur dioxide, nitric acid, methyl nitrate, methanesulfonic acid, and an inorganic sulfate (Grosjean, 1984a).
Chemical/Physical. In the presence of nitric oxide, gaseous methyl mercaptan reacted with OH radicals forming methyl sulfenic acid and methyl thionitrite. The rate constant for this reaction is 2.1 x 10^-11 cm³/molecule?sec at 20 °C (MacLeod et al., 1984). Forms a crystalline hydrate with water (Patnaik, 1992).

9.26 Shipping: UN1064 Methyl mercaptan, Hazard Class: 2.3; Labels: 2.3-Poisonous gas, 2.1-Flammable gas, Inhalation Hazard Zone C. Cylinders must be transported in a secure upright position, in a well-ventilated truck. Protect cylinder and labels from physical damage. The owner of the compressed gas cylinder is the only entity allowed by federal law (49CFR) to transport and refill them. It is a violation of transportation regulations to refill compressed gas cylinders without the express written permission of the owner.

9.27 Asparagus: Methanethiol is a byproduct produced by the metabolism of asparagus. The ability to produce methanethiol in urine after eating asparagus was once thought to be a genetic trait. However recent research suggests that the peculiar odor is in fact produced by all humans after consuming asparagus, while the ability to detect it (methanethiol being one of many components in "asparagus pee") is in fact the genetic trait. The chemical components responsible for the change in the odor of urine show as soon as 15 minutes after eating asparagus.

9.28 Incompatibilities: Violent reaction with strong oxidizers, bleaches, copper, nickel and their alloys; aluminum. Reacts with acids producing flammable and toxic hydrogen sulfide

9.29 Waste Disposal: Return refillable compressed gas cylinders to supplier. Consult with environmental regulatory agencies for guidance on acceptable disposal practices. Generators of waste containing this contaminant (≥100 kg/mo) must conform to EPA regulations governing storage, transportation, treatment, and waste disposal. Incineration followed by effective scrubbing of the effluent gas.

9.30 Storage Conditions: e preparation method is to put water and thiourea into the reaction kettle, add dimethyl sulfate dropwise, when the temperature naturally rises to 80～90℃, start to heat to 116～120℃, react for 30～40min, discharge, cool and centrifuge , The filter cake is methyl isothiourea sulfate, and then lye is added dropwise to methyl isothiourea sulfate at 80° C., and methyl mercaptan is continuously produced. Methyl mercaptan can also be obtained by reacting methyl chloride and sodium hydrosulfide. Add 36% sodium hydrosulfide into the autoclave, press nitrogen into the methyl chloride, start stirring, control the temperature not to exceed 100°C and the pressure not to exceed 1.7 MPa, and react For 30 minutes, when the temperature and pressure drop to a moderate level, open the pressure valve, control the pressure and flow, and obtain sodium methyl mercaptan after washing and absorption. CH3Cl+NaHS[Pressure]→CH3SH+NaClCH3SH+NaOH→CH3SNa+H2O

9.31 Storage features: The warehouse is ventilated, low temperature and dry; stored separately from oxidants and acids

10. Computational chemical data

Molecular Weight: 48.10746g/mol
Molecular Formula: CH₄S
Compound Is Canonicalized: True
XLogP3-AA: 0.5
Exact Mass: 48.00337130
Monoisotopic Mass: 48.00337130
Complexity: 2
Rotatable Bond Count: 0
Hydrogen Bond Donor Count: 1
Hydrogen Bond Acceptor Count: 1
Topological Polar Surface Area: 1
Heavy Atom Count: 2
Defined Atom Stereocenter Count: 0
Undefined Atom Stereocenter Count: 0
Defined Bond Stereocenter Count: 0
Undefined Bond Stereocenter Count: 0
Isotope Atom Count: 0
Covalently-Bonded Unit Count: 1
CACTVS Substructure Key Fingerprint: AAADcYAAAABAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAEAQAAAAAAAAAAACCAAAAAAQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA==

11. Question & Answer

What are the Uses and Dangers of Methanethiol? Oct 21 2019
Methanethiol, the lowest thiol in aliphatic hydrocarbons, possesses a pungent odor and a threshold value of 0.01×10-6. It exhibits hypnotic properties and high concentrations can lead to paralysis of ..

12. Recommended Suppliers

Global33SuppliersView all >>

Tianjin Furun Tongda International Trade Co., LTD Diamond member

1YR

Products:Plastic particles, chemical products
Tel:+86-0-18032801167
Email:Nora@furuntongda.com

Factory Supply methanethiol CAS 74-93-1 with best price

Purity:99%Packing: 200kg/bag FOB
Price: 50 USD/kg
Time: 2024/11/15

Inquire

Hebei Crovell Biotech Co. Ltd Diamond member

4YRS

Products:Cosmetic Raw Materials,solvents,etc.
Tel:86-311-66562153
Email:breeduan@crovellbio.com

Factory Supply methanethiol CAS 74-93-1

Purity:99%Packing: 200kg/bag FOB
Price: 1 USD/kilogram
Time: 2024/11/15

Inquire

Henan Tianfu Chemical Co.,Ltd Diamond member

2YRS

Products:Medical Intermediate,Lithium Battery Additive,Organicetc Chemical, Organic Chemical, Paint Chemical and Detergent Chemical etc..
Tel:0086-0371-55170693
Email:info@tianfuchem.com

Methyl mercaptan

Purity:99%Packing: 200kg/bag FOB
Price: 100 USD/kilogram
Time: 2024/11/15

Inquire

Hangzhou Utanpharma biology co,.Ltd Diamond member

7YRS

Products:Sulindac?Acid?;Roxadustat;Upadacitinib;Relugolix;Moxifloxacin;Ticagrelor;Valsartan;Ivabradine;Fingolimod;Fluvoxamine ;HPMC;PVP;Emagliflozine;D-Cycloserine;D-Proline;L-Proline;L-tert-Leucine
Tel:86-571-87758773
Email:balas@utanpharma.com

METHYL MERCAPTAN