2-Propanethiol
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2-Propanethiol
structure -
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CAS No:
75-33-2
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Formula:
C3H8S
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Chemical Name:
2-Propanethiol
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Synonyms:
2-Propanethiol;Isopropyl mercaptan;Isopropanethiol;Isopropylthiol;2-Mercaptopropane;1-Methylethanethiol;2-Propylmercaptan;i-Propylthiol;NSC 87537;i-Propanethiol
- Categories:
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CAS No:
Description
liquid with an exceedingly unpleasant smell
Isopropyl mercaptan is a white liquid with a strong skunk-like odor. (USCG, 1999)|Liquid|colourless liquid with onion odour
Isopropyl mercaptan is a white liquid with a strong skunk-like odor. (USCG, 1999)|Propane-2-thiol is an alkanethiol that is propane substituted by a sulfanyl group at position 2.
2-Propanethiol Basic Attributes
76.16
76.16
605260
200-861-4
E52LR62ETC
87537
2402
DTXSID1025481
Colorless liquid
29309098
Characteristics
1
1.7 (est)
Colorless Liquid
0.8143 g/cm3 @ Temp: 20 °C
-130.5 °C
52.5 °C @ Press: 760 Torr
<−30 °F
n20/D 1.426(lit.)
Slightly soluble in water
Flammables area
455 mm Hg ( 37.8 °C)
2.6 (vs air)
Inhalation-Mouse LC50: 130000 mg/m3/1 hour
Inflammable in case of open flame, high temperature and oxidant; produces toxic sulfur oxide gas in case of acid and water
Vapor may explode if ignited in an enclosed area.
Extremely unpleasant odor
4.20e-11 cm3/molecule*sec
Henry's Law constant = 4.6X10-3 atm-cu m/mol at 25 °C (est)
pKa = 10.86
Boiling range 51-55 °C|Hydroxyl radical reaction rate constant = 4.20X10-11 cu cm/molec sec at 25 °C
Highly flammable. Soluble in water.
Sulfides, Organic
Highly Flammable
ISOPROPYL MERCAPTAN is incompatible with acids, diazo and azo compounds, halocarbons, isocyanates, aldehydes, alkali metals, nitrides, hydrides, and other strong reducing agents. Reactions with these materials generate heat and in many cases hydrogen gas. May liberate hydrogen sulfide when mixed with an acid.
Safety Information
II
3
UN 2402 3/PG 2
3
11-36/37/38-36/38
16-26-9-37/39-33
TZ7302000
F,Xi
The warehouse is ventilated, low temperature and dry; stored separately from oxidants and acids
Stable. Highly flammable - note low flashpoint. May form explosive mixtures with air.
P210-P261-P305 + P351 + P338
H225-H315-H319-H335
SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational exposure or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal, aquatic, and plant life; and conformance with environmental and public health regulations.|Ethyl mercaptan is a waste chemical stream constituent which may be subjected to ultimate disposal by controlled incineration (2,000 °F) followed by scrubbing with a caustic solution.|Incineration ... : Incinerate scrap material under controlled conditions using afterburner and a scrubber to neutralize sulfur dioxide ... .
Special Hazards of Combustion Products: Irritating sulfur dioxide gas is formed in fire. Behavior in Fire: Vapor is heavier than air and may travel to a source of ignition (USCG, 1999)|Flammable - 3rd degree
|Danger|H225 (98.38%): Highly Flammable liquid and vapor [Danger Flammable liquids]|P210, P233, P240, P241, P242, P243, P261, P264, P270, P271, P280, P301+P312, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P311, P321, P330, P332+P313, P337+P313, P362, P370+P378, P403+P233, P403+P235, P405, and P501|Aggregated GHS information provided by 1477 companies from 14 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.
Excerpt from ERG Guide 130 [Flammable Liquids (Water-Immiscible / Noxious)]: As an immediate precautionary measure, isolate spill or leak area for at least 50 meters (150 feet) in all directions. LARGE SPILL: Consider initial downwind evacuation for at least 300 meters (1000 feet). FIRE: If tank, rail car or tank truck is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2016)
Excerpt from ERG Guide 130 [Flammable Liquids (Water-Immiscible / Noxious)]: ELIMINATE all ignition sources (no smoking, flares, sparks or flames in immediate area). All equipment used when handling the product must be grounded. Do not touch or walk through spilled material. Stop leak if you can do it without risk. Prevent entry into waterways, sewers, basements or confined areas. A vapor-suppressing foam may be used to reduce vapors. Absorb or cover with dry earth, sand or other non-combustible material and transfer to containers. Use clean, non-sparking tools to collect absorbed material. LARGE SPILL: Dike far ahead of liquid spill for later disposal. Water spray may reduce vapor, but may not prevent ignition in closed spaces. (ERG, 2016)
Self-contained breathing apparatus; goggles or face shield; rubber gloves (USCG, 1999)|Self-contained breathing apparatus; goggles or face shield; rubber gloves.|Plastic gloves; goggles or face shield.|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 n-butyl mercaptan. Workers should be provided with and required to use splashproof safety goggles where ethyl mercaptan may come in contact with the eyes.
Highly flammable, dangerous fire hazard.
Vapor may explode if ignited in an enclosed area.
Extinguish with dry chemicals, alcohol foam, or carbon dioxide. Water may be ineffective on fire. Cool exposed containers with water.|If material /is/ on fire or involved in /a/ fire: Do not extinguish fire unless flow can be stopped. Use water in flooding quantities as fog. Solid streams of water may spread fire. Cool all affected containers with flooding quantities of water. Apply water from as far a distance as possible. Use "alcohol" foam, dry chemical or carbon dioxide. /Butyl mercaptan/|Evacuation: If fire becomes uncontrollable or container is exposed to direct flame-consider evacuation of one-third (1/3) mile radius. If material leaking (not on fire) consider evacuation from downwind area based on amount of material spilled, location and weather conditions.
Vapor is heavier than air and may travel to a source of ignition and flash back.
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.|Personnel protection: Avoid breathing vapors. Keep upwind. ... Do not handle broken packages unless wearing appropriate personal protective equipment. Wash away any material which may have contacted the body with copious amounts of water or soap and water. Wear positive pressure self-contained breathing apparatus when fighting fires involving this material. /Butyl Mercaptan/|If material not on fire and not involved in fire: Keep sparks, flames, and other sources of ignition away. Keep material out of water sources and sewers. Build dikes to contain flow as necessary. Attempt to stop leak if without undue personnel hazard. Use water spray to disperse vapors and dilute standing pools of liquid.|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/|For more Preventive Measures (Complete) data for ISOPROPYL MERCAPTAN (10 total), please visit the HSDB record page.
/GUIDE 130: FLAMMABLE LIQUIDS (NON-POLAR/WATER-IMMISCIBLE/NOXIOUS)/ Fire or Explosion: HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames. Vapors may form explosive mixtures with air. Vapors may travel to source of ignition and flash back. Most vapors are heavier than air. They will spread along ground and collect in low or confined areas (sewers, basements, tanks). Vapor explosion hazard indoors, outdoors or in sewers. Those substances designated with a "P" may polymerize explosively when heated or involved in a fire. Runoff to sewer may create fire or explosion hazard. Containers may explode when heated. Many liquids are lighter than water. /Propanethiols/|/GUIDE 130: FLAMMABLE LIQUIDS (NON-POLAR/WATER-IMMISCIBLE/NOXIOUS)/ Health: May cause toxic effects if inhaled or absorbed through skin. Inhalation or contact with material may irritate or burn skin and eyes. Fire will produce irritating, corrosive and/or toxic gases. Vapors may cause dizziness or suffocation. Runoff from fire control or dilution water may cause pollution. /Propanethiols/|/GUIDE 130: FLAMMABLE LIQUIDS (NON-POLAR/WATER-IMMISCIBLE/NOXIOUS)/ Public Safety: CALL Emergency Response Telephone Number ... . As an immediate precautionary measure, isolate spill or leak area for at least 50 meters (150 feet) in all directions. Keep unauthorized personnel away. Stay upwind. Keep out of low areas. Ventilate closed spaces before entering. /Propanethiols/|/GUIDE 130: FLAMMABLE LIQUIDS (NON-POLAR/WATER-IMMISCIBLE/NOXIOUS)/ Protective Clothing: Wear positive pressure self-contained breathing apparatus (SCBA). Structural firefighters' protective clothing will only provide limited protection. /Propanethiols/|For more DOT Emergency Guidelines (Complete) data for ISOPROPYL MERCAPTAN (8 total), please visit the HSDB record page.
No person may /transport,/ offer or accept a hazardous material for transportation in commerce unless that person is registered in conformance ... and the hazardous material is properly classed, described, packaged, marked, labeled, and in condition for shipment as required or authorized by ... /the hazardous materials regulations (49 CFR 171-177)./|The International Air Transport Association (IATA) Dangerous Goods Regulations are published by the IATA Dangerous Goods Board pursuant to IATA Resolutions 618 and 619 and constitute a manual of industry carrier regulations to be followed by all IATA Member airlines when transporting hazardous materials.|The International Maritime Dangerous Goods Code lays down basic principles for transporting hazardous chemicals. Detailed recommendations for individual substances and a number of recommendations for good practice are included in the classes dealing with such substances. A general index of technical names has also been compiled. This index should always be consulted when attempting to locate the appropriate procedures to be used when shipping any substance or article.
Vapor: Irritating to eyes, nose and throat. Liquid: irritating to skin and eyes.
Isopropyl mercaptan was qualitatively detected in crude oil samples collected from TX(1).
Toxicity
moderately toxic
2-Propanethiol potentiated action of bradykinin on rat blood pressure. Potentiation apparently results from thiol complexation of zinc moiety in active center of carboxypeptidase B-type enzyme.
LD50 Rat oral > 2000 mg/kg|LC50 Rat inhalation >1792 mg/kg/4 hr
Isopropyl mercaptan has been qualitatively detected in crude oil samples(1,2). The occurrence of small amounts of alkyl mercaptans in crude oil is believed to result from microbial action on elemental sulfur(2). Mercaptans are formed naturally in biological processes and exist in all living systems(2,3); the lower alkyl mercaptans occur in manure gas from domestic animal pens(2) and have obnoxious odors at low concns(2-4).
Isopropyl mercaptan's production and use as a standard for petroleum analysis and chemical intermediate(1) and natural gas odorant(2) may result in its release to the environment through various waste streams(SRC).
TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 35(SRC), determined from a structure estimation method(2), indicates that isopropyl mercaptan is expected to have very high mobility in soil(SRC). Volatilization of isopropyl mercaptan from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 4.6X10-3 atm-cu m/mole(SRC), using a fragment constant estimation method(3). Isopropyl mercaptan is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 277 mm Hg(4). Biodegradation data were not available(SRC, 2005).|AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 35(SRC), determined from a structure estimation method(2), indicates that isopropyl 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 4.6X10-3 atm-cu m/mole(SRC), developed using a fragment constant estimation method(4). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 3 hours and 3.5 days, respectively(SRC). According to a classification scheme(5), an estimated BCF of 4(SRC), from an estimated log Kow of 1.7(6) and a regression-derived equation(7), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Biodegradation data were not available(SRC, 2005).|ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), isopropyl mercaptan, which has a vapor pressure of 277 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase isopropyl 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 8 hours(SRC), calculated from its rate constant of 4.10X-11 cu cm/molecule-sec at 25 °C(3). Isopropyl mercaptan does not absorb light at wavelengths >290 nm and therefore is not expected to be susceptible to direct photolysis by sunlight.
Rate constants for the vapor-phase reaction of isopropyl mercaptan with photochemically-produced hydroxyl radicals have been reported as 4.20X10-11, 3.9X10-11, and 4.59X10-11 cu cm/molecule-sec at 25 °C(1-3). These values correspond to an atmospheric half-life of about 8 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). The hydroxyl radical reaction proceeds primarily through OH addition to the sulfur(1); based upon chamber experiments with similar sulfur compounds(4), the reaction products may include isopropylsulfonic acid(SRC). Isopropyl mercaptan is not expected to undergo hydrolysis in the environment due to the lack of hydrolyzable functional groups(5). Isopropyl mercaptan does not absorb light at wavelengths >290 nm and therefore is not expected to be susceptible to direct photolysis by sunlight.
An estimated BCF of 4 was calculated for isopropyl mercaptan(SRC), using an estimated log Kow of 1.7(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is low(SRC).
Using a structure estimation method based on molecular connectivity indices(1), the Koc of isopropyl mercaptan can be estimated to be 35(SRC). According to a classification scheme(2), this estimated Koc value suggests that isopropyl mercaptan is expected to have very high mobility in soil.
The Henry's Law constant for isopropyl mercaptan is estimated as 4.6X10-3 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that isopropyl mercaptan is expected to volatilize from water surfaces(2). Based on this Henry's Law constant, the volatilization half-life from a model river (1 m deep, flowing 1 m/sec, wind velocity of 3 m/sec)(2) is estimated as 3 hours(SRC). The volatilization half-life from a model lake (1 m deep, flowing 0.05 m/sec, wind velocity of 0.5 m/sec)(2) is estimated as 3.5 days(SRC). Isopropyl mercaptan's Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC). Isopropyl mercaptan is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 277 mm Hg(3).
NIOSH (NOES Survey 1981-1983) has statistically estimated that 4,715 workers are potentially exposed to isopropyl mercaptan in the USA(1). Occupational exposure to isopropyl mercaptan may occur through inhalation and dermal contact with this compound at workplaces where isopropyl mercaptan is produced or used(SRC). Use data suggest that the general population may be exposed to isopropyl mercaptan via inhalation of ambient air in the vicinity of natural gas refineries and operations(SRC).
Drug Information
Simple aliphatic and aromatic thiols undergo S-methylation in mammals to produce the corresponding methyl thioether or sulfide. Methylation is catalysed by thiopurine methyltransferase in the cytoplasm and thiol methyltransferase in microsomes, and both reactions require S-adenosyl-l-methionine as a methyl group donor. Thiopurine methyltransferase is present in human liver, kidney, and erythrocytes; preferential substrates for this enzyme include aromatic and heterocyclic thiols. S-Methylation of aliphatic thiols is catalysed by microsomal thiol methyltransferase, and the resulting methyl thioether (sulfide) metabolite would undergo S-oxidation to give the methyl sulfoxide and methyl sulfone analogues as urinary products. Thiols may react with glutathione and other endogenous thiol substances to form mixed disulfides. Both microsomal and cytoplasmic thioltransferasess have been reported to catalyse the formation of mixed disulfides. The resulting mixed disulfides can undergo reduction back to thiols, oxidative desulfuration, or oxidation to a sulfonic acid via the intermediate thiosulfinate and sulfinic acids. The principal form in the circulation would probably be a mixed disulfide formed with albumin. /Simple thiols/|Conversion of endogenous toxic mercaptans into nontoxic thioether products via methylation, ie, alkane thiol s-methyltransferase located in endoplasmic reticulum and extracted through detergent solubilization. /Mercaptans/
Inhalation causes loss of sense of smell, muscular weakness, convulsions, respiratory paralysis. Ingestion causes nausea and vomiting. Contact with eyes or skin causes irritation. (USCG, 1999)
INHALATION: remove victim to fresh air; start artificial respiration and give oxygen if required; observe for signs of pulmonary edema; get medical attention. INGESTION: give large amount of water and induce vomiting. EYES or SKIN: flush with water. (USCG, 1999)
/SRP:/ Basic treatment: Establish a patent airway. Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilations if necessary. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Monitor for pulmonary edema and treat if necessary ... . Anticipate seizures and treat if necessary ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with normal saline during transport ... . Do not use emetics. For ingestion, rinse mouth and administer 5 m1/kg up to 200 ml of water for dilution if the patient can swallow, has a strong gag reflex, and does not drool ... . Administer activated charcoal ... . Cover skin burns with dry sterile dressings after decontamination ... . /Sulfur and related compounds/|/SRP:/ Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious. Early intubation at the first sign of upper airway obstruction may be necessary. Monitor cardiac rhythm and treat arrhythmias if necessary ... . Start an IV with D5W /SRP: "To keep open", minimal flow rate/. Use lactated Ringer's if signs of hypovolemia are present. Watch for signs of fluid overload. Consider drug therapy for pulmonary edema ... . Treat seizures with diazepam ... . For hypotension with signs of hypovolemia, administer fluid cautiously. Consider vasopressors for hypotension with a normal fluid volume. Watch for signs of fluid overload ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Sulfur and related compounds/
/SIGNS AND SYMPTOMS/ Strong, offensive smell of mercaptans can cause headache and nausea. High concentrations of their vapors in atmosphere can produce unconsciousness with cyanosis, a sense of coldness at extremities and quickening of pulse ...pulmonary edema. /Mercaptans/|/SIGNS AND SYMPTOMS/ In the manufacture of rubber, irritant contact dermatitis may occur from a variety of acids, alkalies, detergents, and solvents used in the process. Allergic contact dermatitis occurs not infrequently and is almost always due to an organic accelerator or antioxidant. /Mercapto compounds/
2-Propanethiol Use and Manufacturing
Propylene and hydrogen sulfide.|Thiols can be prepared by a variety of methods. The most-utilized of these synthetic methods for tertiary and secondary thiols is acid-catalyzed synthesis; for normal and secondary thiols, the most-utilized methods are free-radical-initiated, alcohol substitution, or halide substitution; for mercaptoalcohols, the most-utilized method is oxirane addition; and for mercaptoacids and mercaptonitriles, the most-utilized methods are Michael-type additions. /Thiols/
Standard for petroleum analysis, intermediate.
Intermediates
Fuels and related products
(1991) Exceeded 5000 lb or US $5000 in value
Liquid grade /Pennwalt Corp/|Technical grade /Phillips Chemical/
All other basic organic chemical manufacturing|2-Propanethiol: ACTIVE
Thiols were converted with a 0.01 M soln of tributyltin hydroxide in hexane to tributyltin mercaptides. Part of the hexane soln was evaporated in a small test tube on a water bath, hexane vapor was removed and the remaining mercaptides were decomposed with 3 M hydrochloric acid saturated with amonium sulfate. A sample of 1.2 ml from the total headspace of 1.3 ml was applied on the column of a gas chromatograph using nitrogen gas and flame ionization defection. The avg standard deviation of the peak height for 10 nmol of each of seven different thiols was 11%. ...|A gas chromatographic technique is described for measuring various volatile sulfur cmpd (H2S, COS, CS2, thiols, sulfides, disulfides) in air at parts per trillion level. The sulfur /containing/ cmpd are trapped and concentrated at -196 °C in a small glass tube filled with porous polymer Tenax GC. The excess of water in the air samples is pretrapped by calcium chloride, a drying agent does not adsorb any of the sulfur volatiles. The Texax trap tube fits exactly in the injection port of the gas chromatograph, where the adsorbed sulfur cmpd are liberated at 200 °C directly into the carrier gas stream and are transferred to the gas chromatographic column. The sulfur cmpd are then assayed by means of a flame photometric detector. The Tenax trap tubes can be stored at -196 °C for more than 1 wk without any loss of sulfur volatiles.
Food additives -> Flavoring Agents|Flavoring Agents -> JECFA Flavorings Index|Fire Hazards -> Flammable - 3rd degree
Flavoring Agents
Computed Properties
Molecular Weight:76.16
XLogP3:1.3
Hydrogen Bond Donor Count:1
Hydrogen Bond Acceptor Count:1
Exact Mass:76.03467143
Monoisotopic Mass:76.03467143
Topological Polar Surface Area:1
Heavy Atom Count:4
Complexity:10.8
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes
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