Butanethiol Chemical Properties

Melting point:

−116 °C(lit.)

Boiling point:

98 °C(lit.)

Density 

0.842 g/mL at 25 °C(lit.)

vapor density 

3.1 (vs air)

vapor pressure 

83 mm Hg ( 37.7 °C)

refractive index 

n20/D 1.443(lit.)

FEMA 

3478 | 1-BUTANETHIOL

Flash point:

55 °F

storage temp. 

Store below +30°C.

solubility 

Slightly soluble in water, soluble in alcohol and oils.

pka

11.51 at 25 °C (23.0% aqueous tert-butyl alcohol, Friedman et al., 1965)

form 

Liquid

color 

Colorless

Specific Gravity

0.842

Odor

Strong skunk-like.

Odor Threshold

0.0000028ppm

Odor Type

sulfurous

explosive limit

1.4-11.3%(V)

Water Solubility 

0.60 g/100 mL. Slightly soluble

Sensitive 

Air Sensitive

Merck 

14,1577

JECFA Number

511

BRN 

1730908

Henry's Law Constant

(x 10^-3 atm?m³/mol): 7.04 at 20 °C (approximate - calculated from water solubility and vapor pressure)

Exposure limits

NIOSH REL: 15-min ceiling 0.5 ppm (1.8 mg/m³), IDLH 500 ppm; OSHA PEL: TWA 10 ppm (35 mg/m³); ACGIH TLV: TWA 0.5 ppm (adopted).

Dielectric constant

4.9500000000000002

Stability:

Stable. Incompatible with oxidizing agents, bases, alkali metals. Highly flammable. May discolour on exposure to air.

LogP

2.28

CAS DataBase Reference

109-79-5(CAS DataBase Reference)

NIST Chemistry Reference

1-Butanethiol(109-79-5)

EPA Substance Registry System

Butyl mercaptan (109-79-5)

Safety Information

Hazard Codes 

F,Xn

Risk Statements 

11-20/22-36/37/38-21/22-43

Safety Statements 

16-23-26-36-9-36/37-33-37-37/39

OEL

Ceiling: 0.5 ppm (1.8 mg/m3) [15-minute]

RIDADR 

UN 2347 3/PG 2

WGK Germany 

3

RTECS 

EK6300000

F 

10-13-23

TSCA 

Yes

HS Code 

2930 90 98

HazardClass 

3

PackingGroup 

II

Hazardous Substances Data

109-79-5(Hazardous Substances Data)

Toxicity

LD50 orally in Rabbit: 1500 mg/kg

IDLA

500 ppm

MSDS

• Language:English Provider:ACROS
• Language:English Provider:SigmaAldrich
• Language:English Provider:ALFA

Butanethiol Usage And Synthesis

Description

Butane thiol, also known as butyl mercaptan, is a volatile, clear to yellowish liquid with a fetid (extremely foul-smelling) odor, commonly described as "skunk" odor. In fact, butanethiol is structurally similar to several major constituents of a skunk's defensive spray but is not actually present in the spray. The scent of butanethiol is so strong that the human nose can easily detect it in the air at concentrations as low as 10 parts per billion. The threshold level for 1-butane thiol is reported as 1.4 ppb.

Chemical Properties

Butanethiol is chemically classified among the thiols, which are organic compounds with molecular formulas and structural formulas similar to alcohols, except that sulfur-containing sulfhydryl group (- SH) replaces the oxygen-containing hydroxyl group in the molecule. Butanethiol's basic molecular formula is C₄H₉SH, and its structural formula is similar to that of the alcohol n-butanol. Butanethiol is prepared by the free radical catalyzed addition of hydrogen sulfide to 1-butene. Commercially, this is performed using ultraviolet light. Butanethiol is a thiol of low molecular weight, and it is highly flammable.

Chemical Properties

1-Butanethiol has an unpleasant (skunk) odor.

Chemical Properties

colourless liquid

Chemical Properties

Butanethiol is also known as butyl mercaptan. It is a volatile, highly flammable clear to yellowish liquid with an extremely foul-smelling, strong, garlic-, cabbageor skunk-like Butanethiol is also known as butyl mercaptan. It is a volatile, highly flammable clear to yellowish liquid with an extremely foul-smelling, strong, garlic-, cabbageor skunk-like

Physical properties

Clear, colorless liquid with a strong garlic, cabbage, or pungent skunk-like odor. Odor threshold concentrations of 0.0028 ppb_v and 3.7 μg/m³ (1.0 ppb_v) were reported by Katz and Talbert (1930) and Nagata and Takeuchi (1990), respectively.

Occurrence

Reported found in beef, cheddar cheese, raw chicken, cooked potatoes, beer and boiled eggs.

Uses

Intermediate, solvent.

Uses

Butanethiol is used as an industrial solvent , and as an intermediate for cotton defoliants. It is some times placed in the "stink bombs" and "stink perfumes" for prankster.

Uses

Solvent; intermediate in the production of insecticides and herbicides; gas odorant

Definition

ChEBI: Butanethiol is an alkanethiol.

Production Methods

Butanethiol is produced from n-Butanol plus Hydrogen sulfide over catalyst.

Synthesis Reference(s)

Journal of the American Chemical Society, 72, p. 1073, 1950 DOI: 10.1021/ja01159a005

General Description

Butanethiol is also known as butyl mercaptan. It is a volatile, clear to yellowish liquid with an extremely foul smell, with a strong, garlic-, cabbage-, or skunk-like odour. It is slightly oily in nature. Butanethiol is used as a chemical intermediate in the production of insecticides and herbicides. It is also used as a gas odorant.

Air & Water Reactions

Highly flammable. Slightly soluble in water.

Reactivity Profile

Butanethiol 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 upon decomposition or reaction with an acid. Incompatible with strong oxidizing agents [USCG, 1999].

Hazard

Toxic by inhalation. Flammable, dangerous fire risk. Upper respiratory tract irritant.

Health Hazard

Inhalation causes loss of sense of smell; muscular weakness. convulsions, and respiratory paralysis may follow prolonged exposure. Contact of liquid with eyes or skin causes slight irritation. Ingestion causes nausea.

Health Hazard

Exposures to butanethiol cause adverse health effects and poisoning. The symptoms of poisoning in exposed workers include, but are not limited to, asthenia, muscular weak ness, malaise, sweating, nausea, vomiting, headache, restlessness, increased respiration, incoordination, muscular weakness, skeletal muscle paralysis in most cases, heavy to mild cyanosis, lethargy and/or sedation, respiratory depression followed by coma. Severe cases of poisoning lead to death of the exposed worker. In laboratory studies, animals given intraperitoneal and oral exposures of butane thiol survived near-lethal single doses. However, after 20 days post-treatment, animals showed pathological changes involving liver and kidney damage. The pathomorpho logical changes in the liver included cloudy swelling, fatty degeneration, and necrosis. Pathological changes in the kidneys included cloudy swelling, and the lungs displayed capillary engorgement, patchy edema, and occasional hemorrhage

Chemical Reactivity

Reactivity with Water No reaction; Reactivity with Common Materials: No reactions; Stability During Transport: Stable; Neutralizing Agents for Acids and Caustics: Not pertinent; Polymerization: Not pertinent; Inhibitor of Polymerization: Not pertinent.

Safety Profile

Poison by intraperitoneal route. Moderately toxic by ingestion. An eye irritant. Dangerous fire hazard by exposure to heat, flame, sparks, or powerful oxidizers. Reacts violently with HNO3. Incompatible with acids, acid fumes, oxidizing materials, heat, flame, and sparks. To fight fire, use alcohol foam. When heated to decomposition it emits toxic SOx. See also MERCAPTANS.

Safety

Butanethiol is a very noxious and caustic chemical compound, and at sufficiently high concentrations, it produces serious health effects in both humans and animals, especially as a result of prolonged exposure. Higher concentrations can lead to unconsciousness and coma after prolonged exposure. Contact with the skin and mucous membranes causes burns, and contact with the eyes can lead to blurred vision or complete blindness.
Inhalation may cause weakness, confusion, cough, dizziness, drowsiness, headache, nausea, vomiting, and shortness of breath. The substance irritates the eyes, the skin, and the respiratory tract. It may cause effects on the thyroid and the nervous system and could cause lowering of consciousness.

Potential Exposure

Butyl mercaptan is a flammable, colorless liquid with a strong, skunk-like odor. The Odor Threshold in air is 0.00097 ppm. Molecular weight 5 90.19; Specific gravity (H2O:1) 5 0.83 @ 20C; boiling point 5 99C;freezing/melting point 5 2116C; vapor pressure 5 35 mmHg @ 20C; 75 mmHg @ 34.5C; relative vapor density (air 5 1) 5 3.1; Flash point 5 2C (cc); Autoignition temperature # 225C. Explosive limits: LEL: 1.4%; UEL: 10.2%. Hazard identification (based on NFPA-704 M Rating System): Health 1; flammability 3; reactivity 0 ?. Slightly soluble in water; solubility 5 0.06% @ 20C.

First aid

If this chemical gets into the eyes, remove anycontact lenses at once and irrigate immediately for at least15 min, occasionally lifting upper and lower lids. Seekmedical attention immediately. If this chemical contactsthe skin, remove contaminated clothing and wash immediately with soap and water. Speed in removing materialfrom skin is of extreme importance. Shampoo hairpromptly if contaminated. Seek medical attention immediately. If this chemical has been inhaled, remove fromexposure, begin rescue breathing (using universal precautions, including resuscitation mask) if breathing hasstopped and CPR if heart action has stopped. Transferpromptly to a medical facility. When this chemical hasbeen swallowed, get medical attention. Give large quantities of water and induce vomiting. Do not make an unconscious person vomit.

Environmental Fate

Chemical/Physical. Releases toxic sulfur oxide fumes when heated to decomposition (Sax and Lewis, 1987).

storage

Color Code—Red: Flammability Hazard: Store ina flammable liquid storage area or approved cabinet awayfrom ignition sources and corrosive and reactive materials.Store in tightly closed containers in a cool, well-ventilatedarea away from heat, oxidizers, or acids.

Shipping

UN2347 Butyl mercaptan, Hazard Class: 3; Labels: 3—Flammable liquid

Purification Methods

Dry the thiol with CaSO4 or Na2SO4, then reflux it over magnesium, or dry with, and distil it from CaO, under nitrogen [Roberts & Friend J Am Chem Soc 108 7204 1986.] It has been separated from hydrocarbons by extractive distillation with aniline. Dissolve it also in 20% NaOH, extract with a small amount of *C6H6, then steam distil it until clear. The solution is then cooled and acidified slightly with 15% H2SO4. The thiol is distilled out, dried with CaSO4 or CaCl2, and fractionally distilled under N2 [Mathias & Filho J Phys Chem 62 1427 1958]. It has also been purified by precipitation as the lead mercaptide from alcoholic solution, then regeneration by adding dilute HCl to the residue followed by steam distillation. All operations should be carried out in a fume cupboard due to the TOXICITY and obnoxious odour of the thiol. [Beilstein 1 IV 1555.]

Incompatibilities

May form explosive mixture with air. Incompatible with oxidizers (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); contact may cause fires or explosions. Keep away from alkaline materials, strong bases, strong acids, oxoacids, epoxides. Attacks some plastics and rubber

Waste Disposal

Incineration (1093C) followed by scrubbing with a caustic solution.

Precautions

Butanethiol decomposes an heading and release toxic fumes. It reacts with strong acids, bases and strong oxidants. Workers during handling of butanethiol should be very careful, should avoid open flames, sparkings, and smoking. Chemical vapor/air mixtures cause explosion ha3 and workers should wear protective cloathing, safety goggles and breathing apparatus and should work in good ventillation

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