tert-Butyl mercaptan

90.19

90.19

200-890-2

489PW92WIV

0019

229569

2347

DTXSID0026418

Mobile liquid|COLORLESS LIQUID

29309090

1

2.14 (est)

Clear colorless Liquid

0.80 g/cm³

-0.5 °C

-63.7-64.2 °C @ Press: 760 Torr

−12 °F

1.437

Slightly soluble in water

Flammables area

303.5 mm Hg ( 37.7 °C)

3.1 (vs air)

Oral-Rat LD50: 4729 mg/kg

Open flame, heat, oxidant is combustible; in case of acid, heat releases toxic sulfur oxide gas

Lower members of the group /mercaptans/, such as...butyl mercaptan...form explosive mixtures with air. /mercaptans/

Heavy skunk odor

3.31e-11 cm3/molecule*sec

Henry's Law constant = 6.1X10-3 atm-cu m/mol at 25 °C (est)

pKa = 11.22 at 25 °C

WT/GALLON: 6.71 LB; DISTILLATION RANGE: 62-67 °C|Freezing point = 34 °F|Hydroxyl radical reaction rate constant = 3.31X10-11 cu cm/molec-sec at 25 °C

The vapour is heavier than air and may travel along the ground; distant ignition possible.

II

3.1

UN 2347 3/PG 2

3

11-41-65-43-36-51/53

3-16-26-39-38-36/37-61

TZ7660000

F,Xi,Xn,N

The warehouse is ventilated, low temperature and dry; lightly loaded and unloaded, stored separately from oxidants and acids

Stable. Flammable - note low flashpoint. Incompatible with strong oxidizing agents.

P210-P273-P280

H225-H317-H411

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.

Reacts with strong acids, strong bases, metals, strong oxidants, strong reducing agents to produce sulfur oxides.|It can react vigorously with oxidizing materials.

Highly flammable. Vapour/air mixtures are explosive.|Flammable - 3rd degree

|Danger|H225 (22.84%): Highly Flammable liquid and vapor [Danger Flammable liquids]|P210, P233, P240, P241, P242, P243, P261, P264, P272, P273, P280, P301+P310, P302+P352, P303+P361+P353, P305+P351+P338, P321, P331, P333+P313, P337+P313, P363, P370+P378, P391, P403+P235, P405, and P501|Aggregated GHS information provided by 578 companies from 7 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.|H225: Highly Flammable liquid and vapor [Danger Flammable liquids]|P210, P233, P240, P241, P242, P243, P260, P261, P264, P271, P272, P280, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P312, P314, P321, P333+P313, P337+P313, P363, P370+P378, P403+P233, P403+P235, P405, and P501

According to degree of possible exposure, persons working with mercaptans should wear personal protective equipment; contact with skin and mucous membranes of mercaptans in high or unknown concn should be avoided. /mercaptans/|Personnel protection: ... Wear appropriate chemical protective gloves, boots and goggles. ... Wear positive pressure self-contained breathing apparatus when fighting fires involving this material. /Butyl mercaptan/

Dangerous, when exposed to heat or flame.|In general, mercaptans are flammable substances.

Lower members of the group /mercaptans/, such as...butyl mercaptan...form explosive mixtures with air. /mercaptans/

Alcohol foam, dry chemical, mist, fog.|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/

Evacuate danger area! Remove all ignition sources. Collect leaking and spilled liquid in sealable containers as far as possible. Absorb remaining liquid in sand or inert absorbent and remove to safe place. Do NOT wash away into sewer. Carefully collect remainder, then remove to safe place.

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.|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.|Ventilation control: 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/|For more Preventive Measures (Complete) data for T-BUTYL MERCAPTAN (8 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. /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 T-BUTYL 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.

/Causes/ redness /in/ eyes.|t-Butyl mercaptan/ is irritating to the eyes and the respiratory tract. Exposure at high levels may result in lowering of consciousness.

Evacuate danger area! Personal protection: filter respirator for organic gases and vapours adapted to the airborne concentration of the substance. Remove all ignition sources. Collect leaking and spilled liquid in sealable containers as far as possible. Absorb remaining liquid in sand or inert absorbent. Then store and dispose of according to local regulations. Do NOT wash away into sewer.

Fireproof. Separated from strong oxidants, strong bases, strong acids, metals and strong reducing agents.

A harmful contamination of the air can be reached rather quickly on evaporation of this substance at 20 °C.

The substance is irritating to the eyes and respiratory tract. Exposure at high levels could cause lowering of consciousness.

NO open flames, NO sparks and NO smoking. Closed system, ventilation, explosion-proof electrical equipment and lighting. Do NOT use compressed air for filling, discharging, or handling.

Use ventilation, local exhaust or breathing protection.

Protective gloves.

Wear safety goggles or eye protection in combination with breathing protection.

| 1 - Materials that, under emergency conditions, can cause significant irritation.| 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.| 1 - Materials that in themselves are normally stable but that can become unstable at elevated temperatures and pressures.

moderately toxic

LD50 Rat oral 4729 mg/kg|LD50 Rat inhalation 22,000 ppm/4 hr|LD50 Rat ip 590 mg/kg|LD50 Mouse inhalation 16,500 ppm/4 hr|For more Non-Human Toxicity Values (Complete) data for T-BUTYL MERCAPTAN (6 total), please visit the HSDB record page.

t-Butyl mercaptan's production and use as an odorant in natural gas, as an intermediate, and as a bacterial nutrient(1) 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 49(SRC), determined from a structure estimation method(2), indicates that t-butyl mercaptan is expected to have very high mobility in soil(SRC). Volatilization of t-butyl mercaptan from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 6.1X10-3 atm-cu m/mole(SRC), using a fragment constant estimation method(3). t-Butyl mercaptan is expected to volatilize from dry soil surfaces(SRC) based upon an extrapolated vapor pressure of 181 mm Hg(4). Biodegradation data were not available(SRC, 2005).|AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 49(SRC), determined from a structure estimation method(2), indicates that t-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 6.1X10-3 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 4 days, respectively(SRC). According to a classification scheme(5), an estimated BCF of 9(SRC), from an estimated log Kow of 2.1(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), t-butyl mercaptan, which has an extrapolated vapor pressure of 181 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase t-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 12 hours(SRC), calculated from its rate constant of 3.31X10-11 cu cm/molecule-sec at 25 °C(3). t-Butyl mercaptan does not absorb light at wavelengths >290 nm and therefore is not expected to be susceptible to direct photolysis by sunlight.

The rate constant for the vapor-phase reaction of t-butyl mercaptan with photochemically-produced hydroxyl radicals is 3.31X10-11 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 12 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). Other experimental rates constant for the vapor-phase reaction of t-butyl mercaptan with photochemically produced hydroxyl radicals were measured as 2.9X10-11(2) and 3.51X10-11(3) cu cm/molecule-sec at 25 °C, corresponding to half-lives of 13.3 and 11.0 hours, respectively, based on a hydroxyl radical concentration of 5X10+5(1). t-Butyl mercaptan is not expected to undergo hydrolysis in the environment due to the lack of hydrolyzable functional groups(4). t-Butyl mercaptan is difficult to convert to the disulfide or oxidize to the sulfonic acid under normal environmental conditions(5). t-Butyl 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 9 was calculated for t-butyl mercaptan(SRC), using an estimated log Kow of 2.1(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 t-butyl mercaptan can be estimated to be 49(SRC). According to a classification scheme(2), this estimated Koc value suggests that t-butyl mercaptan is expected to have very high mobility in soil. Natural gas containing 0.5 lb of t-butyl mercaptan per million cubic feet was passed through a bed of pulverized, dry, raw montmorillonite clay and then measured for loss of odorant. Within 100 standard cubic feet, over 85% of the average influent concentration of t-butyl mercaptan was present in the effluent(3).

The Henry's Law constant for t-butyl mercaptan is estimated as 6.1X10-3 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that t-butyl 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 4 days(SRC). t-Butyl mercaptan's Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC). t-Butyl mercaptan is expected to volatilize from dry soil surfaces(SRC) based upon an extrapolated vapor pressure of 181 mm Hg(3).

SURFACE WATER: t-Butyl mercaptan was detected not quantified in samples from the Winfield Dam at Winfield, West Virginia, and from the Kanawha-Ohio River confluence at Huntington, West Virginia, sampled from August 30 to November 11, 1962(1).

t-Butyl mercaptan was identified as a volatile component of cooked beef flavor(1).

NIOSH (NOES Survey 1981-1983) has statistically estimated that 4,717 workers are potentially exposed to t-butyl mercaptan in the US(1). Occupational exposure to t-butyl mercaptan may occur through inhalation and dermal contact with this compound at workplaces where t-butyl mercaptan is produced or used(SRC). Use data suggest that general population exposure may occur via inhalation of ambient air near natural gas refineries and operations due to use as a natural gas odorant(SRC).

Enzyme system responsible for conversion of endogenous toxic mercaptans in nontoxic thioether products via methylation is located in endoplasmic reticulum. Methylation of thiols studied was minimal in kidneys and brain, high activity seen in lungs. /Mercaptans/|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/

Fresh air, rest. Refer for medical attention.

Remove contaminated clothes. Rinse and then wash skin with water and soap.

First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.

/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/ /t-Butyl mercaptan/ is irritating to the eyes and the respiratory tract. Exposure at high levels may result in lowering of consciousness.|/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 the extremities and quickning of pulse ... Pulmonary edema /is also observed. /Mercaptans/|/SIGNS AND SYMPTOMS/ /T-butyl mercaptan may cause/ cough, dizziness, headache, nausea, drowsiness /by inhalation/.

2-methyl-2-propanethiol

The substance can be absorbed into the body by inhalation.

Cough. Dizziness. Headache. Nausea. Drowsiness.

Redness.

Grade: 95%

All other basic organic chemical manufacturing|2-Propanethiol, 2-methyl-: 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/

t-Butyl mercaptan was measured in river water using ... gas chromatography and FID detection.

Fire Hazards -> Flammable - 3rd degree