Ethanethiol

Other Classes -> Thiols

Flammable agents - 4th degree

Rodenticides

Active substance -> EU Pesticides database: Not approved

Leek-like odor

Penetrating garlic-like odor

Strong, skunk-like odor.

0.826 at 68 °F (USCG, 1999) - Less dense than water; will float

0.8315 at 25 °C/4 °C

Relative density (water = 1): 0.839

0.833-0.839

0.826

0.8315 @25 °C

0.7 % (NIOSH, 2024)

Soluble in alcohol, ether, petroleum naphtha

Soluble in acetone, dilute alkali

In water, 15,603 mg/L at 25 °C

Solubility in water, g/100ml at 20 °C: 0.68

Slightly soluble in water

less than 0 °F (USCG, 1999)

-48.3 C

-48.3 °C (Closed cup)

-54 °C (Closed cup)

-48.3 °C

-55 °F

Danger

H224: Extremely flammable liquid and vapor [Danger Flammable liquids]

P210, P233, P240, P241, P242, P243, P261, P264, P270, P271, P273, P280, P301+P317, P303+P361+P353, P304+P340, P316, P321, P330, P370+P378, P391, P403+P233, P403+P235, P405, and P501 (click each P-code to see the statement)

Danger

H225 (93.1%): Highly Flammable liquid and vapor [Danger Flammable liquids]

P210, P233, P240, P241, P242, P243, P261, P264, P270, P271, P273, P280, P301+P317, P303+P361+P353, P304+P340, P317, P330, P370+P378, P391, P403+P235, and P501 (click each P-code to see the statement)

Chemical: Ethanethiol

Commission Regulation (EC) No 1565/2000 (Repealed by Com.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

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

Status: Active Update: 16-02-2018 https://echa.europa.eu/registration-dossier/-/registered-dossier/2123

Ethanethiol: HSNO Approval: HSR001043 Approved with controls

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.)

Special Hazards of Combustion Products: Irritating fumes of sulfur dioxide are generated.

· HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames.

Extremely flammable. Gives off irritating or toxic fumes (or gases) in a fire. Vapour/air mixtures are explosive.

Dangerous, when exposed to heat or flame or oxidizers.

Minimum ignition temperature in air: 299 °C; in oxygen: 261 °C

Can react vigorously with oxidizing materials.

Extremely flammable.

Inhalation of vapor causes muscular weakness, convulsions, respiratory paralysis. High concentrations may cause pulmonary irritation. Liquid irritates eyes and skin. Ingestion causes nausea and irritation of mouth and stomach. (USCG, 1999)

· May cause toxic effects if inhaled or absorbed through skin.

Its toxicity in rats and mice is similar to that of butyl mercaptan. Acutely, it is about 1/5 as toxic as hydrogen sulfide. Human volunteers exposed to 1mg/m3 (0.5 ppm) experienced no symptoms, while those exposed to 10 mg/m3 (4 ppm) complained of mucous membrane irritation and fatigue. [ACGIH] Liver necrosis occurs in animals receiving sublethal doses. [HSDB] See THIOLS.

2363 129

2363 129

Permissible Exposure Limit: Table Z-1 Ceiling value: 10 ppm (25 mg/cu m).

Vacated 1989 OSHA PEL TWA 0.5 ppm (1 mg/cu m) is still enforced in some states.

Excerpt from ERG Guide 129 [Flammable Liquids (Water-Miscible / Noxious)]:

Use powder, foam, carbon dioxide. In case of fire: keep drums, etc., cool by spraying with water.

Fresh air, rest. Artificial respiration may be needed. Refer for medical attention.

Rinse skin with plenty of water or shower. Rinse skin with plenty of water or shower.

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

Rinse mouth. Rinse mouth. Give one or two glasses of water to drink. Do NOT induce vomiting. Refer for medical attention .

· 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.

Excerpt from NIOSH Pocket Guide for Ethyl mercaptan:

General First Aid:

(General first aid procedures)

· Wear positive pressure self-contained breathing apparatus (SCBA).

0.5 [ppm]

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 foam, dry chemical, or carbon dioxide.

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.

Fireproof. Separated from strong oxidants, strong acids. Cool.

Materials which are toxic as stored or which can decomp into toxic components ... should be stored in 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 ... .

Keep tightly closed and in a cool place.

Odorous gases, such as methylmercaptans, mainly present a cosmetic problem. Thus 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.

Odors can be removed from circulating air with charcoal, by catalytic oxidation, or by destruction with a UV scrubber.

If ethyl mercaptan is spilled or leaked, the following steps should be taken: 1. Remove all ignition sources. 2. Ventilate area of spill or leak. 3. For small quantities of liquids contaning ethyl 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 the hood ductwork is free from ethyl mercaptan vapors. Burn the paper in a suitable location away from combustible materials. 4. Large quantities of liquids containing ethyl mercaptan may be absorbed in vermiculite, dry sand, earth, or a similar material and placed in an appropriate container. Ethyl mercaptan should not be allowed to enter a confined space such as a sewer because of the possibility of an explosion. 5. Liquids containing ethyl 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.

Evacuate danger area! Collect leaking liquid in sealable containers. Do NOT wash away into sewer. Personal protection: self-contained breathing apparatus.

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 ... .

EC50 Daphnia magna (Waterflea, <24 hr old) 90-280 mg/L/48 hr; static, 20 °C, hardness: 250 mg/L CaCO3, dissolved oxygen: >6.5 mg/L, pH 8.2

LC50 Daphnia magna (Water flea) 170 ug/L/48 hr; static /formulated product/

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 22(SRC), determined from a water solubility of 1.56X10+4 mg/L(2) and a regression-derived equation(3), indicates that ethyl mercaptan is expected to have very high mobility in soil(SRC). Volatilization of ethyl mercaptan from moist soil surfaces is expected to be an important fate process(SRC) given a Henry's Law constant of 4.53X10-3 atm-cu m/mole(4). Ethyl mercaptan is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 529 mm Hg(5). Biodegradation data were not available(SRC, 2005).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 22(SRC), determined from a water solubility of 1.56X10+4 mg/L(2) and a regression-derived equation(3), indicates that ethyl mercaptan is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(3) based upon a Henry's Law constant of 4.53X10-3 atm-cu m/mole(4). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 2.4 hours and 3.2 days, respectively(SRC). According to a classification scheme(5), an estimated BCF of 2.7(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), ethyl mercaptan, which has a vapor pressure of 529 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase ethyl 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 10 hours(SRC), calculated from its rate constant of 4.68X10-11 cu cm/molecule-sec at 25 °C(3). Ethyl mercaptan does not absorb light at wavelengths >290 nm and therefore is not expected to be susceptible to direct photolysis by sunlight.

The substance can be absorbed into the body by inhalation and by ingestion.

inhalation, ingestion, skin and/or eye contact

Dizziness. Headache. Nausea. Vomiting. Tremor. Weakness. Unconsciousness.

Redness.

Redness. Pain.

See Inhalation.

irritation mucous membrane; headache, nausea; In Animals: incoordination, lassitude (weakness, exhaustion); liver, kidney damage; cyanosis; narcosis

Ethyl mercaptan concentrations of 0.25-1.01 mg/L were detected in the effluent of the Barceloneta waste treatment facility in Puerto Rico in Sept 1981(1); the treatment facility receives mostly industrial waste(1). An ethyl mercaptan concentration of 3.8 ppm was detected in the headspace gas of a wastewater effluent from an unidentified oil refinery(2). An ethyl mercaptan concentration of 72.5 ppm was detected in the headspace gas of a wastewater effluent from an unidentified waste treatment plant(2). A concentration of 21,000 ppm volume was reported in a study measuring gaseous trace compounds from an unspecified municipal landfill site(3).

Prior to placing a worker in a job with a potential for exposure to ethyl mercaptan, the physician should evaluate and document the worker's baseline health status with thorough medical, environmental, and occupational histories, a physical examination, and physiologic and laboratory tests appropriate for the anticipated occupational risk. These should concentrate on the function and integrity of the nervous and respiratory systems. Medical surveillance for respiratory disease should be conducted by using the principles and methods recommended by NIOSH and the American Thoracic Society (ATS). A preplacement medical evaluation is recommended in order to detect and assess preexisting or concurrent conditions which may be aggravated or result in increased risk when a worker is exposed to n-butyl mercaptan at or below the NIOSH REL. The examining physician should consider the probable frequency, intensity, and duration of exposure, as well as the nature and degree of the condition, in placing such a worker. Such conditions, which should not be regarded as absolute contraindications to job placement, include chronic diseases of the respiratory system.

The Koc of ethyl mercaptan is estimated as 22(SRC), using a water solubility of 1.56X10+4 mg/L(1) and a regression-derived equation(2). According to a classification scheme(3), this estimated Koc value suggests that ethyl mercaptan is expected to have very high mobility in soil.

Ethyl mercaptan

1

10000

Flammable chemical that can be released at a facility.

A membrane bound enzymatic activity found in rabbit liver microsomes which catalyzes transmethylation from s-adenosylmethionine to series of c1-c3 alkane thiols. Methane and ethane thiols are endogenous toxins. Methylation could play role in metabolic detoxification.

Metabolism of ethyl mercaptan studied in rabbits. Ethyl methyl sulfide and diethyl sulfide were detected in blood and expired air.

... In dogs ... and ... guinea pigs in vitro ... ethanethiol is oxidatively metabolized to the sulfate probably via a sulfonic intermediate. One of the intermediate products is also postulated to involve ethylmethionine with a S-adenosylthionine enzyme as a mediator.

Mercaptans ... in small amount, occur naturally in urine, and appear to be related to nature of diet. ... Mercaptans also result from reduction of disulfides and may undergo methylation to form methyl alkyl sulfides, which are oxidized to corresponding sulfones. However, most of these sulfur compounds are metabolized eventually into sulfate.

For more Metabolism/Metabolites (Complete) data for ETHYL MERCAPTAN (6 total), please visit the HSDB record page.

In rabbits after inhalation of 30 ppm for 25 min, trace amounts were detected in blood, while inhalation of 10,000 ppm for 60 min resulted in significant amount of gas in blood. After exposure ended, amount present was very small and diminished rapidly.

Ethylmercaptan is rapidly absorbed, but also readily excreted by the mammalian system. Even in a normal subject, 5.9 ug/cu m of the thiol is exhaled.

Rabbits that inhaled 30 ppm for 25 min had trace amounts of ethyl mercaptan in the blood. Inhalation of 10,000 ppm for 60 min resulted in significant amounts in the blood. After the exposure ended, the amount present in the blood was very small and diminished very rapidly.

Used as an odorant for natural gas; used as an intermediate in the plastic, pesticide, and organic chemical industries; [ACGIH]

Odorant for natural gas; intermediate and starting material in manufacture of plastics, insecticides, antioxidants.

Intermediate in production of acaricides, defoliants, pharmaceuticals, and adhesives

2023: 7,000,000 - <8,500,000 lb

Ethanethiol is listed as a High Production Volume (HPV) chemical (65FR81686). Chemicals listed as HPV were produced in or imported into the U.S. in >1 million pounds in 1990 and/or 1994. The HPV list is based on the 1990 Inventory Update Rule. (IUR) (40 CFR part 710 subpart B; 51FR21438).

(1991) Exceeded 5000 lb or US $5000 in value

... From sodium ethylsulfate and KSH /potassium thiol/; ... catalytically from ethanol and hydrogen sulfide.

By saturating potassium hydroxide solution with hydrogen sulfide, mixing with calcium ethylsulfate solution and distilling on water bath.

Ethanethiol is prepared from ethylene and hydrogen sulfide in the gas phase over aluminum oxide catalysts containing potassium tungstate or nickel and tungsten oxides.

... Ethanethiol is obtained from ethylene and hydrogen sulfide in the liquid phase in the presence of azobisisobutyronitrile and tributylphosphine.

Flavouring Agent -> FLAVOURING_AGENT -> JECFA Functional Classes

Flavoring Agents -> JECFA Flavorings Index

Flavouring Agent -> FLAVOURING_AGENT -> JECFA Functional Classes

Petroleum Refineries

Ethanethiol: 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/

Has one of the most penetrating and persistent odors known (skunk). Tomato juice is reported to deodorize materials contaminated with this compound.