| GHS-Einstufung | DangerH220: Extremely flammable gas [Danger Flammable gases]P203, P210, P222, P261, P271, P273, P280, P304+P340, P316, P321, P377, P381, P391, P403, P403+P233, P405, and P501 (click each P-code to see the statement)H220 (> 99.9%): Extremely flammable gas [Danger Flammable gases]P203, P210, P222, P261, P271, P273, P280, P304+P340, P316, P321, P377, P381, P391, P403, P403+P233, P405, P410+P403, and P501 (click each P-code to see the statement) |
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| Hazards Identification | Toxic/poison by inhalation (TIH/PIH) |
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| Regulatorische Informationen | Chemical: MethanethiolHazard Traits - NeurotoxicityRegulation (EC) No 1831/2003 (amended)Methanethiol is listed on the EPA's Chemical Data Reporting (CDR) system. Manufacturers and importers of Methanethiol are required to report information about their production and use of this chemical to the EPA under the Toxic Substances Control Act (TSCA). (40 eCFR Part 711)T - indicates a substance that is the subject of a final TSCA section 4 test rule.Status: Active Update: 05-07-2013 https://echa.europa.eu/registration-dossier/-/registered-dossier/13716 |
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| DOT-Kennzeichnung | Poison Gas Flammable Gas |
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| Brandgefahren | Combustion produces irritating sulfur dioxide. Flash back along vapor track may occur. Very dangerous when exposed to heat, flame, or oxidizers. On decomposition it emits highly toxic fumes of sulfur oxides. It will react with water, steam or acids to produce toxic and flammable vaporsand can react vigorously with oxidizing materials. Irritating sulfur dioxide is produced upon combustion. When heated to decomposition, it 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. (EPA, 1998)· These materials are extremely flammable.Extremely flammable. Gas/air mixtures are explosive. |
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| Brandpotenzial | Very dangerous, when exposed to heat, flamecan react vigorously with oxidizing materials. |
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| Gesundheitsgefahren | Can cause death by respiratory paralysis. It is an eye and respiratory tract irritant. Exposure results in pulmonary edema and hepatic and renal damage. (EPA, 1998)· TOXICExtremely Hazardous. |
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| Gefahrenübersicht | Methyl mercaptan is a colorless gas with a smell like rotten cabbage. It is a natural substance found in the blood, brain, and other tissues of people and animals. It is released from animal feces. It occurs naturally in certain foods, such as some nuts and cheese. Methyl mercaptan is released from decaying organic matter in marshes and is present in the natural gas of certain regions in the United States, in coal tar, and in some crude oils. It is manufactured for use in the plastics industry, in pesticides, and as a jet fuel additive. It is also released as a decay product of wood in pulp mills.A pulmonary irritant that can cause pulmonary edema after inhalation of high concentrationsLiver injury has been documented after occupational exposure. In high concentrations methyl mercaptan can cause coma and death, acting as a chemical asphyxiant similar to hydrogen sulfide. [ACGIH] Methemoglobinemia has been reported after occupational exposure. [HSDB] Possible frostbite from contact with liquid[NIOSH] |
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| DOT-Nummer und Handbuch | 1064 117 |
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| FDA-Anforderungen | 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. |
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| Reaktive Gruppe | Sulfides, Organic |
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| EG-Einstufung | Symbol: F+, T, NR: 12-23-50/53S: (2)-16-25-60-61 |
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| UN-Einstufung | UN Hazard Class: 2.3UN Subsidiary Risks: 2.1 |
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| Brandbekämpfung | Keep unnecessary people awayisolate hazard area and deny entry. Stay upwindkeep out of low areas. Ventilate closed spaces before entering them. Wear positive pressure breathing apparatus and special protective clothing. Evacuate area endangered by gas. Isolate for 1/2 mile in all directions if tank car or truck is involved in fire.Shut off supplyif not possible and no risk to surroundings, let the fire burn itself out. In other cases extinguish with powder, carbon dioxide. In case of fire: keep cylinder cool by spraying with water. |
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| Erste-Hilfe-Maßnahmen | Fresh air, rest. Artificial respiration may be needed. Refer for medical attention.Remove contaminated clothes. Refer for medical attention . ON FROSTBITE: rinse with plenty of water, do NOT remove clothes.First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention. |
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| Freisetungsmaßnahmen | · CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper not available or no answer, refer to appropriate telephone number listed on the inside back cover.· ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area. |
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| Erste Hilfe | Warning: Effects may be delayed. Caution is advised.General First Aid:(General first aid procedures) |
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| Sichere Lagerung | Fireproof. Separated from strong oxidants and acids. Cool. Store in an area without drain or sewer access. |
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| Firefighting Hazards | Flashback along vapor trail may occur. |
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| Expositionsschutz und Persönliche Schutzausrüstung | · Wear positive pressure self-contained breathing apparatus (SCBA).TIH (Toxic Inhalation Hazard) - Term used to describe gases and volatile liquids that are toxic when inhaled. Some are TIH materials themselves, e.g., chlorine, and some release TIH gases when spilled in water, e.g., chlorosilanes. [ERG 2016].0.5 [ppm] |
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| Brandbekämpfungsverfahren | Stop flow of gas before extinguishing fire. Use water spray to control fire by preventing its spread and absorbing some of its heat.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. |
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| Lagerbedingungen | Separate from oxidizing materials. Store in a cool, dry, well-ventilated location.Store in a cool place. |
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| Reinigungsverfahren | Stop or control the leak, if this can be done with undue risk. Use water spray to cool and disperse vapors, protect personnel, and dilute spills to form nonflammable mixtures. Control runoff and isolate discharged material for proper disposal.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. |
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| Freisetung ohne Brand | Excerpt from ERG Guide 117 [Gases - Toxic - Flammable (Extreme Hazard)]: |
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| Entsorgungsverfahren | 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.SRP: Wastewater from contaminant suppression, cleaning of protective clothing/equipment, or contaminated sites should be contained and evaluated for subject chemical or decomposition product concentrations. Concentrations shall be lower than applicable environmental discharge or disposal criteria. Alternatively, pretreatment and/or discharge to a permitted wastewater treatment facility is acceptable only after review by the governing authority and assurance that "pass through" violations will not occur. Due consideration shall be given to remediation worker exposure (inhalation, dermal and ingestion) as well as fate during treatment, transfer and disposal. If it is not practicable to manage the chemical in this fashion, it must be evaluated in accordance with EPA 40 CFR Part 261, specifically Subpart B, in order to determine the appropriate local, state and federal requirements for disposal.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 °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 °C and residence times of seconds for liquids and gases, and hours for solids. |
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| Toxikologische Informationen | CDC-ATSDR Toxicological Profile |
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| Körperbelastung | Methyl mercaptan appears in urine within an hour after eating asparagus(1). |
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| Wechselwirkungen | Epigallocatechin gallate (EGCg), the main antimicrobial tea catechin, has been reported to inhibit growth and virulence factors of oral pathogens in vitro. Although the mechanism is unclear, the potential of EGCg in reducing halitosis caused by volatile sulfur compounds (VSCs) has been suggested. This study tested the hypothesis that EGCg reduces VSCs by suppressing mgl, the gene encoding L-methionine-alpha-deamino-gamma-mercaptomethane-lyase, responsible for methyl mercaptan (CH3SH) production by oral anaerobes. In this study, the effect of EGCg on in vitro growth, CH3SH production, and mgl gene expression in P. gingivalis W83 was investigated. EGCg inhibited growth of P. gingivalis W83 (MIC = 97.5 ug/mL) and was bactericidal (MBC = 187.5 ug/mL). At sub-MIC levels, EGCg inhibited CH3SH production, and mgl mRNA and protein expression (p < 0.05). /The authors/ conclude that EGCg may represent a natural and alternative agent to the antimicrobial chemicals currently available for halitosis control....The doses of ip injected ammonium acetate or sodium octanoate needed to induce hepatic coma (coma following acute necrosis of the liver) were greatly reduced when /rats/ were exposed to methyl mercaptan at 1,200 ppm within 1 minute after injection. /It was/ suggested that methyl mercaptan exposure may intensify the toxic effects of ammonia and fatty acids in human hepatic failure.Methanethiol is associated with hepatic failure in humans and the synergistic action of methanethiol, ammonia and octanoate is sufficient to account for the coma of experimental hepatic necrosis. ...Interactions between mercaptans, including methyl mercaptan, and ammonium acetate or sodium octanoate in the induction of coma in rats has been reported. ...Human exposure to methyl mercaptan in conjunction with hepatotoxins may result in exacerbated liver damage and/or neurotoxicity. There is a possibility of these multiple exposures in the workplace and in the vicinity of hazardous waste sites.... Ammonia and fatty acids accentuated respiratory paralysis and coma due to exposure to methanethiol. |
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| Zielorgane | Hematological (Blood Forming), Neurological (Nervous System)Eyes, skin, respiratory system, central nervous system, blood |
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| Ökotoxizitätswerte | LC50Species: SalmonidesConcentration: 0.55-0.9 mg/L /Conditions of bioassay not specified/ |
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| Umweltverhalten | TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 13(SRC), determined from a structure estimation method(2), indicates that methyl mercaptan is expected to have very high mobility in soil(SRC). Gaseous methyl mercaptan has been observed to partition to soils(3). For example, when gaseous methyl mercaptan was passed over six air-dried and moist (50% field capacity) soils, 2.4-32.1 mg/g and 2.2-21.4 mg/g of methyl mercaptan rapidly adsorbed to the dry and moist soils, respectively(3). It was suggested that adsorption to soil surfaces might be an environmental sink for gaseous methyl mercaptan(3). Volatilization of methyl mercaptan from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 0.0031 atm-cu m/mole(SRC), based upon its vapor pressure, 1,510 mm Hg at 25 °C(4), and water solubility, 15,400 mg/L(5). Methyl mercaptan is expected to volatilize rapidly from dry soil surfaces based upon its vapor pressure and because it is a gas a temperatures above 6 °C(SRC). However, the importance of volatilization from soil surfaces may be attenuated by gas-phase adsorption to soil surfaces(SRC). Methyl mercaptan is produced under anaerobic conditions (e.g., in salt marshes) by a variety of organisms and is often liberated during the decay of sulfur-containing organic matter(6). It may be formed by sulfate-reducing and methane-producing bacteria from methionine, or reversibly formed from dimethyl sulfide and dimethyl disulfide(6). Ultimately, methyl mercaptan may be mineralized to methane, carbon dioxide, and hydrogen sulfide(6). The oxidation and consequent dimerization of methyl mercaptan to dimethyl disulfide occurs for soils supplemented with methionine and its sulfoxide, and sulfone or S-methyl cysteine(7). This results in part from the formation of methyl mercaptan and subsequent dimerization to dimethyl disulfide(7).AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 13(SRC), determined from a structure estimation method(2) indicates that methyl mercaptan is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(3) based upon an estimated Henry's Law constant of 0.0031 atm-cu m/mole(SRC) derived from its vapor pressure, 1,510 mm Hg(4), and water solubility, 15,400 mg/L(5). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 0.8 hours and 2.8 days, respectively(SRC). According to a classification scheme(6), an estimated BCF of 3(SRC), from its estimated log Kow of 0.78(2) and a regression-derived equation(2), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Methyl mercaptan is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(3). Methyl mercaptan is produced under anaerobic conditions (e.g. in salt marshes) by a variety of organisms and is often liberated during the decay of sulfur-containing organic matter(7). It may be formed by sulfate-reducing and methane-producing bacteria from methionine, or reversibly formed from dimethyl sulfide and dimethyldisulfide(7). Ultimately, methyl mercaptan may be mineralized to methane, carbon dioxide, and hydrogen sulfide(7). When incubated in anaerobic lake sediment from Lake Mendota, WI for 4 hr, methyl mercaptan was rapidly mineralized(8).ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), methyl mercaptan, which has a vapor pressure of 1510 mm Hg at 25 °C(2) is expected to exist solely as a vapor/gas in the ambient atmosphere. Methyl mercaptan has a normal boiling point of 5.95 °C(2), so at temperatures above 5.95 °C, methyl mercaptan will exist as a gas in the atmosphere(SRC). Gas-phase methyl mercaptan is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC)the half-life for this reaction in air is estimated to be 11.7 hours(SRC), calculated from its rate constant of 3.29X10-11 cu cm/molecule-sec at 25 °C(3). The half-life for the reaction of methyl mercaptan with ozone in the atmosphere has been reported to be 140 hr(4). The rate constant for the gas-phase reaction of methyl mercaptan with nitrate radicals that exist in the night-time atmosphere ranged from 8.1X10-13 to 12.2X10-13 cu cm/molecule-sec(5)this corresponds to an average atmospheric half-life of about 1 hour(SRC) at an atmospheric concentration of 2.4X10+8 nitrate radicals per cu cm(5). The UV spectrum of methyl mercaptan shows a log epsilon of 0.7 at 290 nm(6) suggesting that methyl mercaptan may be susceptible to direct photolysis by sunlight(SRC). |
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| Lebensmitteluntersuchungswerte | Methyl mercaptan has been identified as a volatile flavor compound in roasted filberts(1). It is also a volatile component of Beaufort cheese, a Gruyere type cheese manufactured in a limited area of the French Alps(2). |
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| Unerwünschte Wirkungen | Occupational hepatotoxin - Secondary hepatotoxins: the potential for toxic effect in the occupational setting is based on cases of poisoning by human ingestion or animal experimentation. |
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| Expositionspfade | The substance can be absorbed into the body by inhalation.inhalation, skin and/or eye contact (liquid) |
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| Ökotoxizitätsauszüge | /AQUATIC SPECIES/ Fish are highly sensitive to methyl mercaptan. ... The no-effect level is 0.5 ppm and the minimum lethal concentration is 0.9 ppm for the coastal cutthroat trout and king and silver salmon. Methyl mercaptan was lethal at 1 ppm to white bass, yellow perch, large- and smallmouth bass, bluegills, and rock bass./AQUATIC SPECIES/ King salmon (Oncorhynchus tschawytscha) (10 fish) were exposed for 120 hours in static cylindrical glass jugs of 18 L capacity. The LC100 was 0.9 mg/L and the LC0 was 0.5 mg/L. The LC100 was 1.75 mg/L and the LC0 was 0.9 mg/L in similarly exposed silver salmon (Oncorhynchus kisutch) and the LC100 was 1.2 mg/L with an LC0 of 0.7 mg/L in coastal cutthroat trout (Salmo clarki). |
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| Plant Concentrations | Trace amounts of methyl mercaptan are present in the roots and leaves of some plants(1). |
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| Signs and Symptoms | Cough. Sore throat. Dizziness. Headache. Nausea. Vomiting. Unconsciousness.ON CONTACT WITH LIQUID: FROSTBITE.Redness. Pain.irritation eyes, skin, respiratory systemnarcosiscyanosisconvulsionsliquid: frostbite |
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| RCRA-Anforderungen | U153As stipulated in 40 CFR 261.33, when methanethiol, as a commercial chemical product or manufacturing chemical intermediate or an off-specification commercial chemical product or a manufacturing chemical intermediate, becomes a waste, it must be managed according to Federal and/or State hazardous waste regulations. Also defined as a hazardous waste is any residue, contaminated soil, water, or other debris resulting from the cleanup of a spill, into water or on dry land, of this waste. Generators of small quantities of this waste may qualify for partial exclusion from hazardous waste regulations (40 CFR 261.5). |
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| TSCA-Anforderungen | All persons who manufacture (including import or manufacture as a byproduct) or process or intend to manufacture or process one or more of the substances in paragraph c of this section, other than as an impurity, after July 29, 1988, to the end of the reimbursement period shall submit letters of intent to conduct testing, submit study plans, conduct tests, and submit data, or submit exemption applications for those substances they manufacture or process, or intend to manufacture or process, as specified in this section, subpart A of this part, and parts 790 and 792 of this chapter for single-phase rulemaking. Methanethiol is included on this list. Required testing: soil adsorption. |
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| CERCLA-Meldepflichtmengen | Persons in charge of vessels or facilities are required to notify the National Response Center (NRC) immediately, when there is a release of this designated hazardous substance, in an amount equal to or greater than its reportable quantity of 100 lb or 45.4 kg. The toll free number of the NRC is (800) 424-8802. The rule for determining when notification is required is stated in 40 CFR 302.4 (section IV. D.3.b).Releases of CERCLA hazardous substances are subject to the release reporting requirement of CERCLA section 103, codified at 40 CFR part 302, in addition to the requirements of 40 CFR part 355. Methyl mercaptan is an extremely hazardous substance (EHS) subject to reporting requirements when stored in amounts in excess of its threshold planning quantity (TPQ) of 500 lbs. |
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| Clean Water Act Anforderungen | Methyl mercaptan is designated as a hazardous substance under section 311(b)(2)(A) of the Federal Water Pollution Control Act and further regulated by the Clean Water Act Amendments of 1977 and 1978. These regulations apply to discharges of this substance. This designation includes any isomers and hydrates, as well as any solutions and mixtures containing this substance. |
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| DHS Chemicals of Interest (COI) | Methyl mercaptan11000045500Flammable chemical that can be released at a facility. |
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| Alarmwort | Achtung |
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| Gefahrenhinweise | Code Gefahrenhinweise Gefahrenklasse Abteilung Alarmwort Symbol P-Code H220 |
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