Ethanethiol

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

H302: Harmful if swallowed [Warning Acute toxicity, oral]

H331: Toxic if inhaled [Danger Acute toxicity, inhalation]

H400: Very toxic to aquatic life [Warning Hazardous to the aquatic environment, acute hazard]

H410: Very toxic to aquatic life with long lasting effects [Warning Hazardous to the aquatic environment, long-term hazard]

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)

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

H302+H332 (11.4%): Harmful if swallowed or if inhaled [Warning Acute toxicity, oral; acute toxicity, inhalation]

H302 (14.7%): Harmful if swallowed [Warning Acute toxicity, oral]

H332 (100%): Harmful if inhaled [Warning Acute toxicity, inhalation]

H400 (100%): Very toxic to aquatic life [Warning Hazardous to the aquatic environment, acute hazard]

H410 (100%): Very toxic to aquatic life with long lasting effects [Warning Hazardous to the aquatic environment, long-term hazard]

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)

Aggregated GHS information provided per 1757 reports by companies from 13 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Information may vary between notifications depending on impurities, additives, and other factors. The percentage value in parenthesis indicates the notified classification ratio from companies that provide hazard codes. Only hazard codes with percentage values above 10% are shown. For more detailed information, please visit ECHA C&L website.

H332: Harmful if inhaled [Warning Acute toxicity, inhalation]

P261, P271, P273, P304+P340, P317, P391, and P501 (click each P-code to see the statement)

H320: Causes eye irritation [Warning Serious eye damage/eye irritation]

H335: May cause respiratory irritation [Warning Specific target organ toxicity, single exposure; Respiratory tract irritation]

H336: May cause drowsiness or dizziness [Warning Specific target organ toxicity, single exposure; Narcotic effects]

H370: Causes damage to organs [Danger Specific target organ toxicity, single exposure]

P210, P233, P240, P241, P242, P243, P260, P261, P264, P264+P265, P270, P271, P273, P280, P301+P317, P303+P361+P353, P304+P340, P305+P351+P338, P308+P316, P317, P319, P321, P330, P337+P317, P370+P378, P391, P403+P233, P403+P235, P405, and P501 (click each P-code to see the statement)

H316: Causes mild skin irritation [Warning Skin corrosion/irritation]

H319: Causes serious eye irritation [Warning Serious eye damage/eye irritation]

P210, P233, P240, P241, P242, P243, P260, P261, P264, P264+P265, P270, P271, P280, P301+P317, P303+P361+P353, P304+P340, P305+P351+P338, P308+P316, P317, P319, P321, P330, P332+P317, P337+P317, P370+P378, P403+P233, P403+P235, P405, and P501 (click each P-code to see the statement)

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

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

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 .

Excerpt from NIOSH Pocket Guide for Ethyl mercaptan:

Eye: IRRIGATE IMMEDIATELY - If this chemical contacts the eyes, immediately wash (irrigate) the eyes with large amounts of water, occasionally lifting the lower and upper lids. Get medical attention immediately.

Skin: SOAP WASH IMMEDIATELY - If this chemical contacts the skin, immediately wash the contaminated skin with soap and water. If this chemical penetrates the clothing, immediately remove the clothing, wash the skin with soap and water, and get medical attention promptly.

Breathing: RESPIRATORY SUPPORT - If a person breathes large amounts of this chemical, move the exposed person to fresh air at once. If breathing has stopped, perform artificial respiration. Keep the affected person warm and at rest. Get medical attention as soon as possible.

Swallow: MEDICAL ATTENTION IMMEDIATELY - If this chemical has been swallowed, get medical attention immediately. (NIOSH, 2024)

General First Aid:

· Call 911 or emergency medical service.

· Ensure that medical personnel are aware of the material(s) involved, take precautions to protect themselves and avoid contamination.

· Move victim to fresh air if it can be done safely.

· Administer oxygen if breathing is difficult.

· If victim is not breathing:

-- DO NOT perform mouth-to-mouth resuscitation; the victim may have ingested or inhaled the substance.

-- If equipped and pulse detected, wash face and mouth, then give artificial respiration using a proper respiratory medical device (bag-valve mask, pocket mask equipped with a one-way valve or other device).

-- If no pulse detected or no respiratory medical device available, provide continuous compressions. Conduct a pulse check every two minutes or monitor for any signs of spontaneous respirations.

· Remove and isolate contaminated clothing and shoes.

· For minor skin contact, avoid spreading material on unaffected skin.

· In case of contact with substance, remove immediately by flushing skin or eyes with running water for at least 20 minutes.

· For severe burns, immediate medical attention is required.

· Effects of exposure (inhalation, ingestion, or skin contact) to substance may be delayed.

· Keep victim calm and warm.

· Keep victim under observation.

· For further assistance, contact your local Poison Control Center.

· Note: Basic Life Support (BLS) and Advanced Life Support (ALS) should be done by trained professionals.

Specific First Aid:

· Wash skin with soap and water.

· In case of burns, immediately cool affected skin for as long as possible with cold water. Do not remove clothing if adhering to skin.

In Canada, an Emergency Response Assistance Plan (ERAP) may be required for this product. Please consult the shipping paper and/or the "ERAP" section.

(General first aid procedures)

Eye: Irrigate immediately - If this chemical contacts the eyes, immediately wash (irrigate) the eyes with large amounts of water, occasionally lifting the lower and upper lids. Get medical attention immediately.

Skin: Soap wash immediately - If this chemical contacts the skin, immediately wash the contaminated skin with soap and water. If this chemical penetrates the clothing, immediately remove the clothing, wash the skin with soap and water, and get medical attention promptly.

Breathing: Respiratory support

Swallow: Medical attention immediately - If this chemical has been swallowed, get medical attention immediately.

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

CAUTION: The majority of these products have a very low flash point. Use of water spray when fighting fire may be inefficient.

SMALL FIRE: Dry chemical, CO2, water spray or alcohol-resistant foam. Do not use dry chemical extinguishers to control fires involving nitromethane (UN1261) or nitroethane (UN2842).

LARGE FIRE: Water spray, fog or alcohol-resistant foam. Avoid aiming straight or solid streams directly onto the product. If it can be done safely, move undamaged containers away from the area around the fire.

FIRE INVOLVING TANKS, RAIL TANK CARS OR HIGHWAY TANKS: Fight fire from maximum distance or use unmanned master stream devices or monitor nozzles. Cool containers with flooding quantities of water until well after fire is out. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank. ALWAYS stay away from tanks in direct contact with flames. For massive fire, use unmanned master stream devices or monitor nozzles; if this is impossible, withdraw from area and let fire burn. (ERG, 2024)

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

Vapor is heavier than air and may travel long distance to a source of ignition and flash back; containers may explode in a fire.

· 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.

· Keep unauthorized personnel away.

· Stay upwind, uphill and/or upstream.

· Ventilate closed spaces before entering, but only if properly trained and equipped.

· ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from 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.

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

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 tank car or highway tank 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, 2024)

Immediate precautionary measure

· Isolate spill or leak area for at least 50 meters (150 feet) in all directions.

· Consider initial downwind evacuation for at least 300 meters (1000 feet).

· If tank, rail tank car or highway tank 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.

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

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 ... .

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.

The worker should immediately wash the skin when it becomes contaminated.

Work clothing that becomes wet should be immediately removed due to its flammability hazard.

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 ETHYL MERCAPTAN (16 total), please visit the HSDB record page.

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

ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from 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, 2024)

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

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.

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

· Structural firefighters' protective clothing provides thermal protection but only limited chemical protection.

0.5 [ppm]

AEGL 1: Notable discomfort, irritation, or certain asymptomatic non-sensory effects. However, the effects are not disabling and are transient and reversible upon cessation of exposure (Unit: ppm)

AEGL 2: Irreversible or other serious, long-lasting adverse health effects or an impaired ability to escape (Unit: ppm)

AEGL 3: Life-threatening health effects or death (Unit: ppm)

Level of Distinct Odor Awareness (LOA) = 0.00014ppm

AEGLs Status: Final

1.0 [ppm]

120 [ppm]

360 [ppm]

0.5 ppm (1.3 mg/m³) [15 minutes]

C 0.5 ppm (1.3 mg/m3) [15-minute]

10 ppm (25 mg/m³)

C 10 ppm (25 mg/m3) See Appendix G

500 ppm (NIOSH, 2024)

500.0 [ppm]

Excerpts from Documentation for IDLHs: Basis for original (SCP) IDLH: The chosen IDLH is based on the mouse 4­hour LC50 of 2,770 ppm [Fairchild and Stokinger 1958 cited by ACGIH 1971]. . . . Human data: None relevant for use in determining the revised IDLH.

See: 75081

8 hr Time Weighted Avg (TWA): 0.5 ppm.

Excursion Limit Recommendation: Excursions in worker exposure levels may exceed 3 times the TLV-TWA for no more than a total of 30 minutes during a work day, and under no circumstances should they exceed 5 times the TLV-TWA, provided that the TLV-TWA is not exceeded.

0.5 ppm as TWA.

0.5 ppm [2003]

1.3 mg/m

CAUTION: The majority of these products have a very low flash point. Use of water spray when fighting fire may be inefficient.

Small Fire

· Dry chemical, CO2, water spray or alcohol-resistant foam.

· Do not use dry chemical extinguishers to control fires involving nitromethane (UN1261) or nitroethane (UN2842).

Large Fire

· Water spray, fog or alcohol-resistant foam.

· Avoid aiming straight or solid streams directly onto the product.

· If it can be done safely, move undamaged containers away from the area around the fire.

Fire Involving Tanks, Rail Tank Cars or Highway Tanks

· Fight fire from maximum distance or use unmanned master stream devices or monitor nozzles.

· Cool containers with flooding quantities of water until well after fire is out.

· Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank.

· ALWAYS stay away from tanks in direct contact with flames.

· For massive fire, use unmanned master stream devices or monitor nozzles; if this is impossible, withdraw from area and let fire burn.

Australia TWA 0.5 ppm (1 mg/cu m)

Belgium TWA 0.5 ppm (1.3 mg/cu m)

Ethyl mercaptan appears as a clear colorless low-boiling liquid (boiling point 97 °F) with an overpowering, garlic-like/skunk-like odor. Flash point -55 °F. Less dense than water and very slightly soluble in water. Vapors are heavier than air. Vapors may irritate nose and throat. May be toxic if swallowed, by inhalation or by contact. Added to natural gas as an odorant. Used as a stabilizer for adhesives.

Colorless liquid with a strong, skunk-like odor; Note: A gas above 95 degrees F; [NIOSH]

COLOURLESS LIQUID WITH PUNGENT ODOUR.

Colourless to yellow liquid; Fruity, sulfur aroma

Colorless liquid with a strong, skunk-like odor.

Colorless liquid with a strong, skunk-like odor. [Note: A gas above 95 °F.]

Colorless liquid [Note: A gas above 95 degrees F].

Leek-like odor

Penetrating garlic-like odor

Strong, skunk-like odor.

93.9 °F at 760 mmHg (USCG, 1999)

Azeotrope with n-pentane (51% ethanethiol) bp: 30.46 °C; with ether (40% ethanethiol) bp: 31.50 °C

35 °C @760 [mm Hg]

-234 °F (USCG, 1999)

-147.8 °C

-144.4 °C

-147.88 °C

less than 0 °F (USCG, 1999)

-48.3 °C (Closed cup)

-54 °C (Closed cup)

-48.3 °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

Soluble (in ethanol)

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

0.8315 @25 °C

2.14 (Air= 1)

Relative vapor density (air = 1): 2.14

442 mmHg (NIOSH, 2024)

529.0 [mmHg]

529 mm Hg at 25 °C /Extrapolated/

Vapor pressure, kPa at 20 °C: 58.9

442 mmHg

Highly flammable. A very dangerous fire hazard. Very slightly soluble in water.

Sulfides, Organic

Highly Flammable

ETHYL MERCAPTAN reacts violently with calcium hypochlorite, May react vigorously with other oxidizing reagents. On contact with strong acids or when heated to decomposition it emits highly toxic fumes of sulfur oxides [Sax, 9th ed., 1996, p. 1575].

Strong oxidizers [Note: Reacts violently with calcium hypochlorite].

Will react with water or steam to produce toxic and flammable vapors.

The substance is a weak acid. Reacts with oxidants causing fire and explosion hazard. Reacts with strong acids producing toxic gases, hydrogen sulfide and sulfur oxides.

Strong oxidizers [Note: Reacts violently with calcium hypochlorite.]

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

Eyes, respiratory system, liver, kidneys, blood

Occupational hepatotoxin - Secondary hepatotoxins: the potential for toxic effect in the occupational setting is based on cases of poisoning by human ingestion or animal experimentation.

Other Poison - Chemical Asphyxiant

LC50 (rat) = 4,420 ppm/4H

LD50 Rat ip 226 mg/kg

LC50 Rat inhalation 2770 ppm/4 hr

LC50 Mouse inhalation 4420 ppm/4 hr

LD50 Rat oral 682 mg/kg

LD50 Rat dermal > 2000 mg/kg

... It supplements the effect of UV light on the epidermis by increasing the skin's histidase activity.

/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/

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.

/HUMAN EXPOSURE STUDIES/ Human volunteers exposed to ethyl mercaptan at 10 mg/cu m (4 ppm) 3 hr daily during 5-10 days showed minimal effects such as rise in olfactory threshold and altered taste reaction to bitter and sweet substances. /Volunteers reported/ periodic nausea, irritation of mucous membranes of lips, mouth, and nose and sensation of fatigue.

/HUMAN EXPOSURE STUDIES/ Male subjects /exposed/ at 50 ppm for 20 min showed in part a decrease in respiration frequency, which was more pronounced at 112 ppm with a minute expiratory value and marked tidal volume increase, but no cardiac or vascular changes. A Russian report states that at 4 ppm, headache, irritation, and nausea were reported, but no signs and symptoms occured at 0.4 ppm.

/SIGNS AND SYMPTOMS/ May be ... /SRP: CNS depressant/ in high concentrations. Irritating to mucous membranes.

/SIGNS AND SYMPTOMS/ Exposure to ethyl mercaptan can cause headache, nausea, weakness, fatigue, incoordination, and irritation of the mucous membranes.

For more Human Toxicity Excerpts (Complete) data for ETHYL MERCAPTAN (7 total), please visit the HSDB record page.

/LABORATORY ANIMALS: Acute Exposure/ Exposure of male rats to a concentration of 33,000 ppm for 15 min caused the loss of the righting reflex to 50% of the animals tested.

/LABORATORY ANIMALS: Acute Exposure/ Male rats survived a 1 hr exposure to 28,400 ppm; three of five female rats died during a 1 hr exposure to 27,700 ppm.

/LABORATORY ANIMALS: Acute Exposure/ Instillation of 0.1 mL of undiluted material into the conjunctival sac of rabbits caused slight irritation.

/LABORATORY ANIMALS: Acute Exposure/ When tested by application of drop in rabbit's eye, only slight irritation developed, but high concentration of vapor caused animals to rub and close their eyes after 15 minutes of exposure, indicating considerable irritation. Characteristic property of thiols, and particularly ethyl mercaptan, is the production of lethargy or sleepiness; relatively deep sedation was produced /in rats/ by maximal, sublethal, ip doses. Sedation persists for one to several hours followed by a lethargic condition. Higher exposures result in restlessness, muscular incoordination, skeletal muscle paralysis, severe to mild cyanosis, resp depression, coma and death. Rats receiving ethyl mercaptan by ip injection showed lymphocytic infiltration in hepatic portal spaces, with occasional necrotic foci.

For more Non-Human Toxicity Excerpts (Complete) data for ETHYL MERCAPTAN (17 total), please visit the HSDB record page.

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/

Ethyl mercaptan's production and use as a liquid petroleum gas odorant, adhesive, stabilizer, and chemical intermediate may result in its release to the environment through various waste streams. Ethyl mercaptan occurs in some vegetables (such as cabbage), mammalian excretion products, manure gas from domestic animal pens, in various crude oils and in natural gas; it is formed by biological processes. If released to air, a vapor pressure of 529 mm Hg at 25 °C indicates ethyl mercaptan will exist solely as a vapor in the ambient atmosphere. Vapor-phase ethyl 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 10 hours. Ethyl 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, ethyl mercaptan is expected to have very high mobility based upon an estimated Koc of 22. Volatilization from moist soil surfaces is expected to be an important fate process based upon a Henry's Law constant of 4.53X10-3 atm-cu m/mole. Ethyl mercaptan may volatilize from dry soil surfaces based upon its vapor pressure. Biodegradation data were not available. If released into water, ethyl 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 2.4 hours and 3.2 days, respectively. An estimated BCF of 2.7 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 ethyl mercaptan may occur through inhalation and dermal contact with this compound at workplaces where ethyl mercaptan is produced or used. Monitoring data indicate that the general population may be exposed to ethyl mercaptan via inhalation of air in the vicinity of natural gas refineries (through usde as an odorant) and municipal waste sites, and dermally in preparation or ingestion of certain meats and vegetables. (SRC)

Ethyl mercaptan is formed in vinous fermentation. It occurs in illuminating gas, in "sour" natural gas of west Texas and in petroleum distillates from which it may be separated by chemical or physical methods(1).

Ethyl mercaptan occurs in illuminating gas, natural "sour" Texas gas wells, petroleum distillates and coal tar(1); it is a natural mammalian excretion product(1); it occurs naturally in some vegetables such as cabbage(1). Ethyl mercaptan has been qualitatively detected in crude oil samples collected from TX(2). The occurrence of small amounts of alkyl mercaptans in crude oil is believed to result from microbial action on elemental sulfur(3). Mercaptans are formed naturally in biological processes and exist in all living systems(3-4); the lower alkyl mercaptans occur in manure gas from domestic animal pens(3). Small amounts of ethyl mercaptan are components of human breath(3). Microbes and natural gas have been identified as sources of ethyl mercaptan emissions to the atmosphere(5).

Ethyl mercaptan occurs naturally in some vegetables such as cabbage(1).

Ethyl mercaptan's production and use as a liquid petroleum gas odorant, adhesive, stabilizer, chemical intermediate(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 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.

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/

Ethyl mercaptan's production and use as a liquid petroleum gas odorant, adhesive, stabilizer, and chemical intermediate may result in its release to the environment through various waste streams. Ethyl mercaptan occurs in some vegetables (such as cabbage), mammalian excretion products, manure gas from domestic animal pens, in various crude oils and in natural gas; it is formed by biological processes. If released to air, a vapor pressure of 529 mm Hg at 25 °C indicates ethyl mercaptan will exist solely as a vapor in the ambient atmosphere. Vapor-phase ethyl 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 10 hours. Ethyl 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, ethyl mercaptan is expected to have very high mobility based upon an estimated Koc of 22. Volatilization from moist soil surfaces is expected to be an important fate process based upon a Henry's Law constant of 4.53X10-3 atm-cu m/mole. Ethyl mercaptan may volatilize from dry soil surfaces based upon its vapor pressure. Biodegradation data were not available. If released into water, ethyl 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 2.4 hours and 3.2 days, respectively. An estimated BCF of 2.7 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 ethyl mercaptan may occur through inhalation and dermal contact with this compound at workplaces where ethyl mercaptan is produced or used. Monitoring data indicate that the general population may be exposed to ethyl mercaptan via inhalation of air in the vicinity of natural gas refineries (through usde as an odorant) and municipal waste sites, and dermally in preparation or ingestion of certain meats and vegetables. (SRC)

Ethyl mercaptan is formed in vinous fermentation. It occurs in illuminating gas, in "sour" natural gas of west Texas and in petroleum distillates from which it may be separated by chemical or physical methods(1).

Ethyl mercaptan occurs in illuminating gas, natural "sour" Texas gas wells, petroleum distillates and coal tar(1); it is a natural mammalian excretion product(1); it occurs naturally in some vegetables such as cabbage(1). Ethyl mercaptan has been qualitatively detected in crude oil samples collected from TX(2). The occurrence of small amounts of alkyl mercaptans in crude oil is believed to result from microbial action on elemental sulfur(3). Mercaptans are formed naturally in biological processes and exist in all living systems(3-4); the lower alkyl mercaptans occur in manure gas from domestic animal pens(3). Small amounts of ethyl mercaptan are components of human breath(3). Microbes and natural gas have been identified as sources of ethyl mercaptan emissions to the atmosphere(5).

Ethyl mercaptan occurs naturally in some vegetables such as cabbage(1).

Ethyl mercaptan's production and use as a liquid petroleum gas odorant, adhesive, stabilizer, chemical intermediate(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 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 rate constant for the vapor-phase reaction of ethyl mercaptan with photochemically-produced hydroxyl radicals is 4.68X10-11 cu cm/molecule-sec at 25 °C(1). This corresponds to an atmospheric half-life of about 10 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(2), the reaction products may include ethylsulfonic acid(SRC). The rate constant for the vapor-phase reaction of ethyl mercaptan with atmospheric nitrate radicals has been experimentally determined to be 1.2X10-12 cu cm/molecule-sec at 25 °C(3) which corresponds to an atmospheric half-life of about 1 hr at an atmospheric concn of 2X10+8 nitrate radicals per cu cm(SRC); the nitrate radical occurs in the lower troposphere during nighttime hours(4). Ethyl mercaptan is not expected to undergo hydrolysis in the environment due to the lack of hydrolyzable functional groups(5). Ethyl 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 2.7 was calculated for ethyl mercaptan(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 BCF suggests the potential for bioconcentration in aquatic organisms is low(SRC).

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.

The Henry's Law constant for ethyl mercaptan is 4.53X10-3 atm-cu m/mole(1). This Henry's Law constant indicates that ethyl 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 2.4 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 3.2 days(SRC). Ethyl mercaptan's Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC). Ethyl mercaptan is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 529 mm Hg(3).

SURFACE WATER: Ethyl mercaptan was qualitatively detected in seawater samples collected in Feb 1978 at an ocean dumpsite near Puerto Rico where pharmaceutical wastes had just been dumped(1). Ethyl mercaptan was detected in only one of 204 water samples (concentration not reported) collected from 14 heavily industrialized river basins in the US(2).

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).

Ethyl mercaptan was qualitatively detected in the volatile components of raw chicken breast muscle(1). The compound has been identified as a beef volatile(2). Ethyl mercaptan occurs naturally in some vegetables such as cabbage(3).

... A TLV, based on the prevention of discomfort and minor irritation (disagreeable odor) of 0.5 ppm. ... In view of the fact that this level exceeds the odor threshold by about 500, it is doubtful that this concentration can be maintained in a workplace without causing a community air pollution problem if appreciable quantities are involved.

NIOSH (NOES Survey 1981-1983) has statistically estimated that 1,793 workers (14 of these are female) are potentially exposed to ethyl mercaptan in the US(1). Occupational exposure to ethyl mercaptan may occur through inhalation and dermal contact with this compound at workplaces where ethyl mercaptan is produced or used(SRC). Monitoring data indicate that the general population may be exposed to ethyl mercaptan via inhalation of air in the vicinity of natural gas refineries (through use as an odorant) and municipal waste sites, and dermally in preparation or ingestion of certain meats and vegetables(SRC).

Small amounts of ethyl mercaptan are components of human breath(1).

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 ... .

/GUIDE 129: FLAMMABLE LIQUIDS (Polar/Water-Miscible/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.

/GUIDE 129: FLAMMABLE LIQUIDS (Polar/Water-Miscible/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.

/GUIDE 129: FLAMMABLE LIQUIDS (Polar/Water-Miscible/Noxious)/ Public Safety: CALL Emergency Response Telephone Number on Shipping Paper first. If Shipping Paper not available or no answer, refer to appropriate telephone number listed on the inside back cover. 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.

/GUIDE 129: FLAMMABLE LIQUIDS (Polar/Water-Miscible/Noxious)/ Protective Clothing: Wear positive pressure self-contained breathing apparatus (SCBA). Structural firefighters' protective clothing will only provide limited protection.

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

UN 2363; ETHYL MERCAPTAN

IMO 3.1; ETHYL MERCAPTAN

49 081 69; Ethyl mercaptan

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.

Flammable Liquid

Symbol: F, Xn, N; R: 11-20-50/53; S: (2)-16-25-60-61

UN Hazard Class: 3; UN Pack Group: I