2-Butanethiol

Other Classes -> Thiols

Flammable agents - 3rd degree

Obnoxious odor

Heavy skunk odor

0.8299 at 17 °C

0.8299 @ 17°C

Colorles liquid

Mobile liquid

Very sol in alc, ether, liquid hydrogen sulfide

In water, 1.32X10+3 mg/L at 20 °C

-165 °C

Liquid molar volume = 0.109430 cu m/kmol. IG Heat of Formation = -9.66X10+7 J/kmol. Heat of fusion at melting point = 6.477X10+6 J/kmol

-165 °C

80.7 [mmHg]

80.71 mm Hg at 25 °C /Extrapolated/

80.71 [mm Hg] @25 °C

Danger

H225 (100%): Highly Flammable liquid and vapor [Danger Flammable liquids]

P210, P233, P240, P241, P242, P243, P261, P264, P264+P265, P271, P272, P273, P280, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P319, P321, P332+P317, P333+P317, P337+P317, P362+P364, P370+P378, P391, P403+P233, P403+P235, P405, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 231 reports by companies from 8 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Danger

H225: Highly Flammable liquid and vapor [Danger Flammable liquids]

Chemical: 2-Butanethiol

Commission Regulation (EC) No 1565/2000 (Repealed by Com. Implementing Reg. (EU) No 872/2012)

2-Butanethiol is listed on the EPA's Chemical Data Reporting (CDR) system. Manufacturers and importers of 2-Butanethiol 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)

2-Butanethiol: Does not have an individual approval but may be used under an appropriate group standard

The New Jersey Worker and Community Right to Know Act requires public and private employers to provide information about hazardous substances at their workplaces. (N.J.S.A. 34:5A-1 et. seq.)

Emergency treatment: Butyl mercaptan; Butyl mercaptan is a mucous membrane irritant with a repulsive odor detectable at sub-toxic concentrations; It causes narcosis and paralysis; It causes pulmonary edema in animals subjected to near lethal doses; [HSDB] May cause moderate eye irritation, based on animal studies; Inhalation of high concentrations can cause CNS depression; [CHEMINFO] An irritant; Exposure may cause CNS depression; [MSDSonline] See 1-Butanethiol. See THIOLS.

/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. /Butyl mercaptan/

/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. /Butyl mercaptan/

/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. /Butyl mercaptan/

/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. /Butyl mercaptan/

For more DOT Emergency Guidelines (Complete) data for SEC-BUTYL MERCAPTAN (8 total), please visit the HSDB record page.

2 - Materials that, under emergency conditions, can cause temporary incapacitation or residual injury.

3 - Liquids and solids that can be ignited under almost all ambient temperature conditions. Materials produce hazardous atmospheres with air under almost all ambient temperatures or, though unaffected by ambient temperatures, are readily ignited under almost all conditions.

0 - Materials that in themselves are normally stable, even under fire conditions.

Flam. Liq. 2 (100%)

Flammable liquids - Category 2

Flammable agents - 3rd degree

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.

UN 2347; Butyl mercaptan

IMO 3.2; Butyl mercaptan

If material on fire or involved in fire: Do not extinguish fire unless flow can be stopped or safely confined. 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/

... Materials which are toxic as stored or which can decompose into toxic components ... should be stored in a cool, well ventilated place, out of the direct rays of the sun, away from areas of high fire hazard, and should be periodically inspected. Incompatible materials should be isolated ...

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.

SRP: Local exhaust ventilation should be applied wherever there is an incidence of point source emissions or dispersion of regulated contaminants in the work area. Ventilation control of the contaminant as close to its point of generation is both the most economical and safest method to minimize personnel exposure to airborne contaminants.

Generally process from which mercaptan vapor is liable to be evolved should as far as practicable be enclosed, and exhaust ventilation should be provided to prevent vapors from diffusing into atmosphere of workroom. /mercaptans/

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. /Butyl mercaptan/

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. ... /Butyl mercaptan/

For more Preventive Measures (Complete) data for SEC-BUTYL MERCAPTAN (6 total), please visit the HSDB record page.

15 [mg/m3]

170 [mg/m3]

1000 [mg/m3]

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 84(SRC), determined from a water solubility of 1.32X10+3 mg/L(2) and a regression-derived equation(3), indicates that sec-butyl mercaptan is expected to have high mobility in soil(SRC). Volatilization of sec-butyl mercaptan from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 7.3X10-3 atm-cu m/mole(SRC), derived from its extrapolated vapor pressure, 81 mm Hg(4), and water solubility(2). sec-Butyl mercaptan is expected to volatilize from dry soil surfaces(SRC) based upon its extrapolated vapor pressure(4). Biodegradation data were not available(SRC, 2005).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 84(SRC), determined from a water solubility of 1.32X10+3 mg/L(2) and a regression-derived equation(3), indicates that sec-butyl 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 7.3X10-3 atm-cu m/mole(SRC), derived from its extrapolated vapor pressure, 81 mm Hg(4), and water solubility(2). 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 4 days, respectively(SRC). According to a classification scheme(6), an estimated BCF of 11(SRC), from its water solubility(2) and a regression-derived equation(3), 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), sec-butyl mercaptan, which has an extrapolated vapor pressure of 81 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase sec-butyl 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 7 hours(SRC), calculated from its rate constant of 4.0X10-11 cu cm/molecule-sec at 25 °C(3). sec-Butyl mercaptan does not absorb light at wavelengths >290 nm and therefore is not expected to be susceptible to direct photolysis by sunlight.

The Koc of sec-butyl mercaptan is estimated as 84(SRC), using a water solubility of 1.32X10+3 mg/L(1) and a regression-derived equation(2). According to a classification scheme(3), this estimated Koc value suggests that sec-butyl mercaptan is expected to have high mobility in soil.

/SIGNS AND SYMPTOMS/ Strong, offensive smell of mercaptans can cause headache and nausea. High concentration of their vapors in atmosphere can produce unconsciousness with cyanosis, a sense of coldness at the extremities and quickening of pulse. ... Pulmonary edema /is also observed/. /Mercaptans/

An estimated BCF of 11 was calculated for sec-butyl mercaptan(SRC), using a water solubility of 1.32X10+3 mg/L(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).

The Henry's Law constant for sec-butyl mercaptan is estimated as 7.3X10-3 atm-cu m/mole(SRC) derived from its vapor pressure, 80.7 mm Hg(1), and water solubility, 1.32X10+3 mg/L(2). This Henry's Law constant indicates that sec-butyl mercaptan is expected to volatilize rapidly from water surfaces(3). 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)(3) 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)(3) is estimated as 4 days(SRC). sec-Butyl mercaptan is expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(1).

/LABORATORY ANIMALS: Acute Exposure/ /In rats/, ... symptoms after oral exposure included ataxia and body weight loss.

/LABORATORY ANIMALS: Acute Exposure/ Instillation into rabbit eyes caused acute pain and moderate conjunctival irritation for 2 days.

/LABORATORY ANIMALS: Neurotoxicity/ Acute neurotoxic effects reported in animals include cholinesterase inhibition. /From table/

/OTHER TOXICITY INFORMATION/ ... /Investigators/ observed that at concentrations near the intraperitoneal LD50 in the rat CNS effects and cholinesterase inhibition occur.

The rate constant for the reaction of sec-butyl mercaptan with hydroxyl radicals has been experimentally determined to be 3.8X10-11 to 4.0X10-11 cu cm/molecule-sec at 25 °C(1-3). This corresponds to an atmospheric half-life range of about 7 to 11 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1-3). sec-Butyl mercaptan is not expected to undergo hydrolysis in the environment due to the lack of hydrolyzable functional groups(4). sec-Butyl mercaptan does not absorb light at wavelengths >290 nm and therefore is not expected to be susceptible to direct photolysis by sunlight.

NIOSH (NOES Survey 1981-1983) has statistically estimated that 4,715 workers are potentially exposed to sec-butyl mercaptan in the US(1). Occupational exposure to sec-butyl mercaptan may occur through inhalation and dermal contact with this compound at workplaces where sec-butyl mercaptan is produced or used(SRC). Use data suggest that the general population may be exposed to sec-butyl mercaptan via inhalation of ambient air in the vicinity of natural gas refineries and operations due to use as a natural gas odorant(SRC).

sec-Butyl mercaptan's production and use as a natural gas odorant may result in its release to the environment through various waste streams. If released to air, an extrapolated vapor pressure of 81 mm Hg at 25 °C indicates sec-butyl mercaptan will exist solely as a vapor in the ambient atmosphere. Vapor-phase sec-butyl mercaptan will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals; the half-life for this reaction in air is estimated to be 7 hours. sec-Butyl mercaptan does not absorb light at wavelengths >290 nm and therefore is not expected to be susceptible to direct photolysis by sunlight. If released to soil, sec-butyl mercaptan is expected to have high mobility based upon an estimated Koc of 84. Volatilization from moist soil surfaces is expected to be an important fate process based upon an estimated Henry's Law constant of 7.3X10-3 atm-cu m/mole. Biodegradation data were not available. If released into water, sec-butyl mercaptan is not expected to adsorb to suspended solids and sediment based upon the estimated Koc. Volatilization from water surfaces is expected to be an important fate process based upon this compound's estimated Henry's Law constant. Estimated volatilization half-lives for a model river and model lake are 3 hours and 4 days, respectively. An estimated BCF of 11 suggests the potential for bioconcentration in aquatic organisms is low. Hydrolysis is not expected to be an important environmental fate process since this compound lacks functional groups that hydrolyze under environmental conditions. Occupational exposure to sec-butyl mercaptan may occur through inhalation and dermal contact with this compound at workplaces where sec-butyl mercaptan is produced or used. Use data suggest that the general population may be exposed to sec-butyl mercaptan via inhalation of ambient air in the vicinity of natural gas refineries and operations due to use as a natural gas odorant. (SRC)

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/

Used as odorant for natural gas and to make Cadusafos; [HSDB]

Petroleum Production and Refining [Category: Industry]

Odorant for natural gas.

Manufacture of Cadusafos

Reaction of 2-butene with hydrogen sulfide in the presence of a catalyst (usually a halide)

Prepared from 2-iodobutane by means of alcoholic K-S-H solution; ... from 2-bromobutane in the same manner.

Raffinate II (n-butenes, mixed: 45-60% 1-butene, 20-40% 2-butene, 10-20% n-butane, 5% isobutene) + hydrogen sulfide (addition)

Pesticide, Fertilizer, and Other Agricultural Chemical Manufacturing

2-Butanethiol: ACTIVE

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/