2-mercaptoethanol

This chemical does not meet GHS hazard criteria for 0.6% (5 of 787) of reports.

H301 (53.5%): Toxic if swallowed [Danger Acute toxicity, oral]

H302 (45.9%): Harmful if swallowed [Warning Acute toxicity, oral]

H310 (44%): Fatal in contact with skin [Danger Acute toxicity, dermal]

H311 (55.4%): Toxic in contact with skin [Danger Acute toxicity, dermal]

H314 (32.4%): Causes severe skin burns and eye damage [Danger Skin corrosion/irritation]

H315 (66.8%): Causes skin irritation [Warning Skin corrosion/irritation]

H317 (56.2%): May cause an allergic skin reaction [Warning Sensitization, Skin]

H318 (66.5%): Causes serious eye damage [Danger Serious eye damage/eye irritation]

H331 (63.7%): Toxic if inhaled [Danger Acute toxicity, inhalation]

H332 (28%): Harmful if inhaled [Warning Acute toxicity, inhalation]

H361 (24.8%): Suspected of damaging fertility or the unborn child [Warning Reproductive toxicity]

H373 (51.8%): May causes damage to organs through prolonged or repeated exposure [Warning Specific target organ toxicity, repeated exposure]

H400 (59.6%): Very toxic to aquatic life [Warning Hazardous to the aquatic environment, acute hazard]

H410 (25.8%): Very toxic to aquatic life with long lasting effects [Warning Hazardous to the aquatic environment, long-term hazard]

H411 (70.8%): Toxic to aquatic life with long lasting effects [Hazardous to the aquatic environment, long-term hazard]

P203, P260, P261, P262, P264, P264+P265, P270, P271, P272, P273, P280, P301+P316, P301+P317, P301+P330+P331, P302+P352, P302+P361+P354, P304+P340, P305+P354+P338, P316, P317, P318, P319, P321, P330, P332+P317, P333+P317, P361+P364, P362+P364, P363, P391, P403+P233, P405, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 787 reports by companies from 37 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Reported as not meeting GHS hazard criteria per 5 of 787 reports by companies.

There are 36 notifications provided by 782 of 787 reports by companies with hazard statement code(s).

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.

H227: Combustible liquid [Warning Flammable liquids]

H301: Toxic if swallowed [Danger Acute toxicity, oral]

H310: Fatal in contact with skin [Danger Acute toxicity, dermal]

H315: Causes skin irritation [Warning Skin corrosion/irritation]

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

H371: May cause damage to organs [Warning Specific target organ toxicity, single exposure]

H373: May causes damage to organs through prolonged or repeated exposure [Warning Specific target organ toxicity, repeated exposure]

P210, P260, P262, P264, P264+P265, P270, P280, P301+P316, P302+P352, P305+P351+P338, P308+P316, P316, P319, P321, P330, P332+P317, P337+P317, P361+P364, P362+P364, P370+P378, P403, P405, and P501 (click each P-code to see the statement)

Fresh air, rest. Half-upright position. Artificial respiration may be needed. Refer for medical attention.

Remove contaminated clothes. Rinse skin with plenty of water or shower. Refer for medical attention .

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

Rinse mouth. Refer for medical attention .

EYES: First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. IMMEDIATELY transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop.

SKIN: IMMEDIATELY flood affected skin with water while removing and isolating all contaminated clothing. Gently wash all affected skin areas thoroughly with soap and water. If symptoms such as redness or irritation develop, IMMEDIATELY call a physician and be prepared to transport the victim to a hospital for treatment.

INHALATION: IMMEDIATELY leave the contaminated area; take deep breaths of fresh air. If symptoms (such as wheezing, coughing, shortness of breath, or burning in the mouth, throat, or chest) develop, call a physician and be prepared to transport the victim to a hospital. Provide proper respiratory protection to rescuers entering an unknown atmosphere. Whenever possible, Self-Contained Breathing Apparatus (SCBA) should be used; if not available, use a level of protection greater than or equal to that advised under Protective Clothing.

INGESTION: DO NOT INDUCE VOMITING. If the victim is conscious and not convulsing, give 1 or 2 glasses of water to dilute the chemical and IMMEDIATELY call a hospital or poison control center. Be prepared to transport the victim to a hospital if advised by a physician. If the victim is convulsing or unconscious, do not give anything by mouth, ensure that the victim's airway is open and lay the victim on his/her side with the head lower than the body. DO NOT INDUCE VOMITING. IMMEDIATELY transport the victim to a hospital. (NTP, 1992)

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:

· For corrosives, in case of contact, immediately flush skin or eyes with running water for at least 30 minutes. Additional flushing may be required.

· Removal of solidified molten material from skin requires medical assistance.

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

Excerpt from ERG Guide 153 [Substances - Toxic and/or Corrosive (Combustible)]:

SMALL FIRE: Dry chemical, CO2 or water spray.

LARGE FIRE: Dry chemical, CO2, alcohol-resistant foam or water spray. If it can be done safely, move undamaged containers away from the area around the fire. Dike runoff from fire control for later disposal.

FIRE INVOLVING TANKS, RAIL TANK CARS OR HIGHWAY TANKS: Fight fire from maximum distance or use unmanned master stream devices or monitor nozzles. Do not get water inside containers. 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. (ERG, 2024)

Use water spray, powder, foam, carbon dioxide.

Alcohol foam

To fight fire use alcohol foam, CO2, or dry chemical.

· 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.

· Do not touch damaged containers or spilled material unless wearing appropriate protective clothing.

· Stop leak if you can do it without risk.

· Prevent entry into waterways, sewers, basements or confined areas.

· Absorb or cover with dry earth, sand or other non-combustible material and transfer to containers.

· DO NOT GET WATER INSIDE CONTAINERS.

Excerpt from ERG Guide 153 [Substances - Toxic and/or Corrosive (Combustible)]:

IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids.

SPILL: Increase the immediate precautionary measure distance, in the downwind direction, as necessary.

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 in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids.

· For highlighted materials: see Table 1 - Initial Isolation and Protective Action Distances.

· For non-highlighted materials: increase the immediate precautionary measure distance, in the downwind direction, as necessary.

· 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.

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.

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.

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational exposure or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal, aquatic, and plant life; and conformance with environmental and public health regulations.

SRP: 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.

Do not eat, drink, or smoke during work.

/First aid/: Remove contaminated clothes, rinse skin with plenty of water or shower, refer for medical attention.

/If contacted with eyes/, first rinse with plenty of water for several minutes (remove contact lenses if easily possible), then take to a doctor.

For more Preventive Measures (Complete) data for 2-MERCAPTOETHANOL (6 total), please visit the HSDB record page.

Excerpt from ERG Guide 153 [Substances - Toxic and/or Corrosive (Combustible)]:

ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area. Do not touch damaged containers or spilled material unless wearing appropriate protective clothing. Stop leak if you can do it without risk. Prevent entry into waterways, sewers, basements or confined areas. Absorb or cover with dry earth, sand or other non-combustible material and transfer to containers. DO NOT GET WATER INSIDE CONTAINERS. (ERG, 2024)

Separated from oxidants, metals and food and feedstuffs. Keep in a well-ventilated room.

Separated from oxidants, metals, food and feedstuffs. Keep in a well-ventilated room.

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

· Wear chemical protective clothing that is specifically recommended by the manufacturer when there is NO RISK OF FIRE.

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

0.60 [ppm]

2.3 [ppm]

14 [ppm]

Small Fire

· Dry chemical, CO2 or water spray.

Large Fire

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

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

· Dike runoff from fire control for later disposal.

Fire Involving Tanks, Rail Tank Cars or Highway Tanks

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

· Do not get water inside containers.

· 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.

Workplace Environmental Exposure Level (WEEL): 8-hr Time-weighted Average (TWA) 0.2 ppm, skin.

No indication can be given about the rate at which a harmful concentration of this substance in the air is reached on evaporation at 20 °C.

The substance is irritating to the eyes, skin and respiratory tract. The substance may cause effects on the central nervous system.

Excerpt from ERG Guide 153 [Substances - Toxic and/or Corrosive (Combustible)]:

Wear positive pressure self-contained breathing apparatus (SCBA). Wear chemical protective clothing that is specifically recommended by the manufacturer when there is NO RISK OF FIRE. Structural firefighters' protective clothing provides thermal protection but only limited chemical protection. (ERG, 2024)

/Wear/ protective gloves, protective clothing, face shield, or eye protection in combination with breathing protection.

NO open flames. Above 74 °C use a closed system and ventilation.

PREVENT GENERATION OF MISTS!

Use ventilation, local exhaust or breathing protection.

Protective gloves. Protective clothing.

Wear face shield or eye protection in combination with breathing protection.

Do not eat, drink, or smoke during work.

Thioglycol appears as a water-white liquid. May be toxic by ingestion, inhalation, or skin absorption.

Water-white liquid with a disagreeable odor; [Hawley] Colorless liquid with a stench; [MSDSonline]

COLOURLESS LIQUID WITH CHARACTERISTIC ODOUR.

Clear colourless liquid; Very unpleasant odour

Water-white mobile liquid

Strong disagreeable odor

315 to 316 °F at 742 mmHg (decomposes) (NTP, 1992)

Decomp at bp 157-158 °C, 742 mm Hg

156-158 °C

-148 °F (NTP, 1992)

165 °F (NFPA, 2010)

165 °F (74 °C) (open cup)

74 °C o.c.

greater than or equal to 100 mg/mL at 68 °F (NTP, 1992)

Miscible with alcohol, ether, and benzene /Pure liquid/

Miscible in most organic solvents.

Miscible in water

Solubility in water: miscible

Practically insoluble or insoluble in water

Soluble (in ethanol)

1.1143 at 68 °F (NTP, 1992) - Denser than water; will sink

1.1143 at 20 °C/4 °C

Relative density (water = 1): 1.1

1.114-1.120 (20 °C)

1.1168 @ 20°C

2.69 (NTP, 1992) - Heavier than air; will sink (Relative to Air)

2.69 (Air = 1)

Relative vapor density (air = 1): 2.7 (calculated)

1 mmHg at 68 °F (NTP, 1992)

1.0 [mmHg]

1.756 mm Hg at 25 °C /Extrapolated/

Vapor pressure, kPa at 20 °C: 0.13

1 [mm Hg] @20 °C

-0.3 (estimated)

When heated to decomposition it emits highly toxic fumes of /sulfur oxides/.

Odor Threshold Low: 0.12 [ppm]

Odor Threshold High: 0.64 [ppm]

[Hawley] Odor threshold from CHEMINFO

0.38 mg/cu m (Odor low) 2.04 mg/cu m (Odor high)

Odor perception threshold is 0.0001 ug/L.

No rapid reaction with air. No rapid reaction with water.

Alcohols and Polyols

Sulfides, Organic

Organosulfides, such as THIOGLYCOL, are 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. Many of these compounds may liberate hydrogen sulfide upon decomposition or reaction with an acid.

Reacts with oxidants and metals.

The substance can be absorbed into the body by inhalation of its vapour, through the skin and by ingestion.

Shortness of breath.

Redness. Pain.

Neurotoxin - Other CNS neurotoxin

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.

Dermatotoxin - Skin burns.

Skin Sensitizer - An agent that can induce an allergic reaction in the skin.

Toxic Pneumonitis - Inflammation of the lungs induced by inhalation of metal fumes or toxic gases and vapors.

LCLo (rat) = 250 ppm/8h

LD50 Mouse ip 200 mg/kg

LD50 Mouse iv 480 mg/kg

LD50 Mouse oral 190 mg/kg bw

LD50 Rat oral 244 mg/kg

For more Non-Human Toxicity Values (Complete) data for 2-MERCAPTOETHANOL (6 total), please visit the HSDB record page.

Sulfhydryl agents, /including/ mercaptoethanol, increase non-specifically the potency of various agonists (acetylcholine, 5-hydroxytryptamine, nicotine, bradykinin, prostaglandin E2) on the guinea pig ileum. These effects are of non-cholinergic origin and are not related to prostaglandin synthesis. Sulfydryl agents act directly on the smooth muscle cells of the guinea pig ileum most probably by reducing disulfide bonds located on the membrane surface and by this mechanism modulate the muscular contractile activity.

The negative inotropic effect produced by low concentration of mercaptoethanol on isolated frog heart was blocked by pretreatment with atropine.

2-Mercaptoethanol induced arteriosclerosis and endothelial cell cytotoxicity in baboons were inhibited by sulfinpyrazone.

... A reduction in SCE frequency was observed when cells were cultured with 20 microM 2-Mercaptoethanol (2-ME )and IL-2 compared to interleukin-2 (IL-2) alone. Three nuclear proteins, with relative molecular masses of approximately 13,000-18,000, 20,000, and 80,000, were phosphorylated in IL-2-exposed G1-phase nuclei. Elicitation of these nuclear proteins in IL-2-exposed cells was not affected by exposure to 2-ME.

...The effect of NaBu plus IL-2 was markedly augmented by 2-mercaptoethanol (2-ME), which showed a slight or null effect on the response of untreated, IL-2-treated or NaBu-treated B cells, as assessed by both anti-TNP plaque-forming cell assay and anti-TNP IgM ELISA. ... 2-ME enhanced the anti-TNP antibody production induced by other short-chain fatty acids with three to five carbon atoms plus IL-2. The proliferation of B cells was significantly inhibited by NaBu or NaBu plus IL-2, and the proliferation was completely restored by the simultaneous addition of 2-ME.

/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/ /2-Mercaptoethanol causes/ redness and pain in eyes and skin. .../Causes/ shortness of breath /via/ inhalation. The substance may cause effects on central nervous system.

/LABORATORY ANIMALS: Acute Exposure/ 2-Mercaptoethanol applied undiluted to the rabbit eye is toxic to the conjunctiva and causes long-lasting moderately severe corneal opacity.

/LABORATORY ANIMALS: Chronic Exposure or Carcinogenicity/ Chronic iv administration of 2-mercaptoethanol produced arteriosclerosis in baboons. It was also cytotoxic to endothelial cells in vitro.

/LABORATORY ANIMALS: Chronic Exposure or Carcinogenicity/ Female RLEF1/Lati rats were chronically treated with 2-mercaptoethanol in a dose of 13 micrograms/100 g bw-1/day-1 dissolved in drinking water. During a 48-h experiment 15N-labelled glycine was given orally in a dose of 5 mg 15N.kg bw-1 and urine samples were collected and analysed by an emission spectrometric isotope method. Protein synthesis and nitrogen excretion rate constants were calculated according to the three-pool model, and 3-methylhistidine excretion rates were also determined. 2-Mercaptoethanol appears to influence protein metabolism; however, the slower rates of protein synthesis proved to be apparent in almost all groups of treated rats. Protein synthesis and nitrogen excretion rate constants have exceptionally high values in 2-year-old rats, possibly explained by the occurrence of hypercompensation mechanisms in old age. These were reflected by the excretion rates of 3-methylhistidine which were reduced as a result of sulphhydryl group interactions in age-dependent cellular metabolic changes.

/LABORATORY ANIMALS: Chronic Exposure or Carcinogenicity/ In old CBA/Ca mice the effect of cigarette smoke was compared with that of 2-mercaptoethanol (2-ME) treatment. It could be stated that spontaneous death was more frequent in animals kept in cigarette smoke than in the control animals. Prevalence of hepatocellular carcinoma was higher in animals kept in cigarette smoke than in the controls. After 2-ME treatment the occurrence of hepatocellular carcinoma was significantly lower and animals without disorders were more frequent than in smokers. Body weights were lower in animals kept in cigarette smoke and differences in organ indices could be observed, too. Immunological changes were also demonstrated: in mice kept in cigarette smoke the reactivity against a foreign antigen such as sheep erythrocytes (SRBC) was lower, while after 2-ME treatment it was higher than in their controls using direct plaque formation technique. The ratio of normal reactivity (against SRBC) and autoreactivity (against mouse erythrocytes) showed a decrease in smoker animals, and an increase in the 2-ME-treated ones. The experiments showed a deleterious effect of cigarette smoke and a beneficial effect of 2-ME on age-related alterations.

For more Non-Human Toxicity Excerpts (Complete) data for 2-MERCAPTOETHANOL (14 total), please visit the HSDB record page.

LC50 Poecilia reticulata (Guppy) 187 mg/L/24 hr /formulated product/ /Conditions of bioassay not specified in source examined/

EC50 Pseudomonas putida (cell multiplic. inhib. test) 125 mg/L/17 hr

EC50 Scenedesmus subspicatus (cell multiplic. inhib. test) 12 mg/L/72 hr

EC50 Daphnia magna (Straus) 3.2 mg/L/24 hr; toxic effect: immobilization /Conditions of bioassay not specified in source examined/

For more Ecotoxicity Values (Complete) data for 2-MERCAPTOETHANOL (10 total), please visit the HSDB record page.

2-Mercaptoethanol's production and use as solvent for dyestuffs, intermediate for producing dyestuffs, pharmaceuticals, rubber chemicals, flotation agents, insecticides, plasticizers, water-soluble reducing agent, biochemical reagent, PVC stabilizers, agricultural chemicals, and textile auxiliary may result in its release to the environment through various waste streams. It is a hydrolysis product of the chemical warfare agent mustard gas. 2-Mercaptoethanol is formed through the decomposition of naturally occurring products such as swine manure and proteins (produced by marine algae and other marine plants). If released to air, an extrapolated vapor pressure of 1.76 mm Hg at 25 °C indicates 2-mercaptoethanol will exist solely as a vapor. Vapor-phase 2-mercaptoethanol 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 8.5 hours. 2-Mercaptoethanol does not contain chromophores that absorb at wavelengths >290 nm and therefore is not expected to be susceptible to direct photolysis by sunlight. If released to soil, 2-mercaptoethanol is expected to have very high mobility based upon an estimated Koc of 1.3. Volatilization from moist soil surfaces is not expected to be an important fate process based upon an estimated Henry's Law constant of 1.8X10-7 atm-cu m/mole. 2-Mercaptoethanol may volatilize from dry soil surfaces based upon its vapor pressure. A 29% biomineralization after 55 days under methanogenic conditions indicates that biodegradation is not an important environmental fate process in anoxic environments. If released into water, 2-mercaptoethanol is not expected to adsorb to suspended solids and sediment based upon the estimated Koc. Volatilization from water surfaces is not expected to be an important fate process based upon this compound's estimated Henry's Law constant. An estimated BCF of 3.0 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 2-mercaptoethanol may occur through inhalation and dermal contact with this compound at workplaces where 2-mercaptoethanol is produced or used. Monitoring data indicate that the general population may be exposed to 2-mercaptoethanol via dermal contact with this compound and other products containing 2-mercaptoethanol. (SRC)

2-Mercaptoethanol has been identified as one of volatile substances evolved from aerobic and anaerobic microbial decomposition of liquid swine manure(1).

2-Mercaptoethanol's production and use as a solvent for dyestuffs, intermediate for producing dyestuffs, pharmaceuticals, rubber chemicals, flotation agents, insecticides, plasticizers, water-soluble reducing agent, biochemical reagent, PVC stabilizers, agricultural chemicals, and textile auxiliary(1) may result in its release to the environment through various waste streams(SRC). 2-Mercaptoethanol is a hydrolysis product of the chemical warfare agent mustard gas(2).

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 1.3(SRC), determined from a structure estimation method(2), indicates that 2-mercaptoethanol is expected to have very high mobility in soil(SRC). Volatilization of 2-mercaptoethanol from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 1.8X10-7 atm-cu m/mole(SRC), derived from its extrapolated vapor pressure, 1.76 mm Hg(4), and an assigned value for water solubility of 1.00X10+6 mg/L (miscible)(3). 2-Mercaptoethanol is expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(4). A 29% biomineralization after 55 days under methanogenic conditions(5) indicates that biodegradation is not an important environmental fate process in anoxic soil environments(SRC).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 1.3(SRC), determined from a structure estimation method(2), indicates that 2-mercaptoethanol is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(3) based upon an estimated Henry's Law constant of 1.8X10-7 atm-cu m/mole(SRC), derived from its vapor pressure, 1.76 mm Hg(4), and assigned water solubility(5). According to a classification scheme(6), an estimated BCF of 3.0(SRC), from an estimated log Kow of -0.20(7) and a regression-derived equation(8), suggests the potential for bioconcentration in aquatic organisms is low(SRC). A 29% biomineralization after 55 days under methanogenic conditions(9) indicates that biodegradation is not an important environmental fate process in anoxic aquatic environments(SRC).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), 2-mercaptoethanol, which has an extrapolated vapor pressure of 1.76 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase 2-mercaptoethanol 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 8.5 hours(SRC), calculated from its rate constant of 4.6X10-11 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). 2-Mercaptoethanol does not contain chromophores that absorb at wavelengths >290 nm and therefore is not expected to be susceptible to direct photolysis by sunlight(SRC).

ANAEROBIC: 2-Mercaptoethanol, was shown to be biomineralized under methanogenic conditions(1). 2-Mercaptoethanol, present at 100 mg/L reached 29% biodegradation in 55 days using 120 mL flasks containing sludge from an upflow anaerobic blanket reactor treating liquid hen manure at 1 g volatile suspended solids (VSS)/L, 0.4 g Chemical Oxygen Demand (COD), basal medium, and incubated at 30 °C(1). Therefore, this compound is not expected to biodegrade rapidly under anaerobic conditions(SRC). Addition of cosubstrates, glucose or a combination of propionic or butyric acids, did not affect the rate of degradation(1). The compound is moderately toxic to microorganisms(1).

The rate constant for the vapor-phase reaction of 2-mercaptoethanol with photochemically-produced hydroxyl radicals has been estimated as 4.6X10-11 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 8.5 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). The rate constant for the reaction between hydroxyl radicals and 2-mercaptoethanol in aqueous solution at pH 6.5 has been experimentally determined to be 6.8X10+9/M-sec(2); assuming that the hydroxyl radical concentration of brightly sunlit natural water is 1X10-17 M(3), the half-life for this reaction would be 118 days(SRC). 2-Mercaptoethanol is not expected to undergo hydrolysis in the environment due to the lack of hydrolyzable functional groups(4). 2-Mercaptoethanol does not contain chromophores that absorb at wavelengths >290 nm and therefore is not expected to be susceptible to direct photolysis by sunlight(SRC).

LC50 Poecilia reticulata (Guppy) 187 mg/L/24 hr /formulated product/ /Conditions of bioassay not specified in source examined/

EC50 Pseudomonas putida (cell multiplic. inhib. test) 125 mg/L/17 hr

EC50 Scenedesmus subspicatus (cell multiplic. inhib. test) 12 mg/L/72 hr

EC50 Daphnia magna (Straus) 3.2 mg/L/24 hr; toxic effect: immobilization /Conditions of bioassay not specified in source examined/

For more Ecotoxicity Values (Complete) data for 2-MERCAPTOETHANOL (10 total), please visit the HSDB record page.

2-Mercaptoethanol's production and use as solvent for dyestuffs, intermediate for producing dyestuffs, pharmaceuticals, rubber chemicals, flotation agents, insecticides, plasticizers, water-soluble reducing agent, biochemical reagent, PVC stabilizers, agricultural chemicals, and textile auxiliary may result in its release to the environment through various waste streams. It is a hydrolysis product of the chemical warfare agent mustard gas. 2-Mercaptoethanol is formed through the decomposition of naturally occurring products such as swine manure and proteins (produced by marine algae and other marine plants). If released to air, an extrapolated vapor pressure of 1.76 mm Hg at 25 °C indicates 2-mercaptoethanol will exist solely as a vapor. Vapor-phase 2-mercaptoethanol 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 8.5 hours. 2-Mercaptoethanol does not contain chromophores that absorb at wavelengths >290 nm and therefore is not expected to be susceptible to direct photolysis by sunlight. If released to soil, 2-mercaptoethanol is expected to have very high mobility based upon an estimated Koc of 1.3. Volatilization from moist soil surfaces is not expected to be an important fate process based upon an estimated Henry's Law constant of 1.8X10-7 atm-cu m/mole. 2-Mercaptoethanol may volatilize from dry soil surfaces based upon its vapor pressure. A 29% biomineralization after 55 days under methanogenic conditions indicates that biodegradation is not an important environmental fate process in anoxic environments. If released into water, 2-mercaptoethanol is not expected to adsorb to suspended solids and sediment based upon the estimated Koc. Volatilization from water surfaces is not expected to be an important fate process based upon this compound's estimated Henry's Law constant. An estimated BCF of 3.0 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 2-mercaptoethanol may occur through inhalation and dermal contact with this compound at workplaces where 2-mercaptoethanol is produced or used. Monitoring data indicate that the general population may be exposed to 2-mercaptoethanol via dermal contact with this compound and other products containing 2-mercaptoethanol. (SRC)

2-Mercaptoethanol has been identified as one of volatile substances evolved from aerobic and anaerobic microbial decomposition of liquid swine manure(1).

2-Mercaptoethanol's production and use as a solvent for dyestuffs, intermediate for producing dyestuffs, pharmaceuticals, rubber chemicals, flotation agents, insecticides, plasticizers, water-soluble reducing agent, biochemical reagent, PVC stabilizers, agricultural chemicals, and textile auxiliary(1) may result in its release to the environment through various waste streams(SRC). 2-Mercaptoethanol is a hydrolysis product of the chemical warfare agent mustard gas(2).

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 1.3(SRC), determined from a structure estimation method(2), indicates that 2-mercaptoethanol is expected to have very high mobility in soil(SRC). Volatilization of 2-mercaptoethanol from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 1.8X10-7 atm-cu m/mole(SRC), derived from its extrapolated vapor pressure, 1.76 mm Hg(4), and an assigned value for water solubility of 1.00X10+6 mg/L (miscible)(3). 2-Mercaptoethanol is expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(4). A 29% biomineralization after 55 days under methanogenic conditions(5) indicates that biodegradation is not an important environmental fate process in anoxic soil environments(SRC).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 1.3(SRC), determined from a structure estimation method(2), indicates that 2-mercaptoethanol is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(3) based upon an estimated Henry's Law constant of 1.8X10-7 atm-cu m/mole(SRC), derived from its vapor pressure, 1.76 mm Hg(4), and assigned water solubility(5). According to a classification scheme(6), an estimated BCF of 3.0(SRC), from an estimated log Kow of -0.20(7) and a regression-derived equation(8), suggests the potential for bioconcentration in aquatic organisms is low(SRC). A 29% biomineralization after 55 days under methanogenic conditions(9) indicates that biodegradation is not an important environmental fate process in anoxic aquatic environments(SRC).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), 2-mercaptoethanol, which has an extrapolated vapor pressure of 1.76 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase 2-mercaptoethanol 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 8.5 hours(SRC), calculated from its rate constant of 4.6X10-11 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). 2-Mercaptoethanol does not contain chromophores that absorb at wavelengths >290 nm and therefore is not expected to be susceptible to direct photolysis by sunlight(SRC).

ANAEROBIC: 2-Mercaptoethanol, was shown to be biomineralized under methanogenic conditions(1). 2-Mercaptoethanol, present at 100 mg/L reached 29% biodegradation in 55 days using 120 mL flasks containing sludge from an upflow anaerobic blanket reactor treating liquid hen manure at 1 g volatile suspended solids (VSS)/L, 0.4 g Chemical Oxygen Demand (COD), basal medium, and incubated at 30 °C(1). Therefore, this compound is not expected to biodegrade rapidly under anaerobic conditions(SRC). Addition of cosubstrates, glucose or a combination of propionic or butyric acids, did not affect the rate of degradation(1). The compound is moderately toxic to microorganisms(1).

The rate constant for the vapor-phase reaction of 2-mercaptoethanol with photochemically-produced hydroxyl radicals has been estimated as 4.6X10-11 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 8.5 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). The rate constant for the reaction between hydroxyl radicals and 2-mercaptoethanol in aqueous solution at pH 6.5 has been experimentally determined to be 6.8X10+9/M-sec(2); assuming that the hydroxyl radical concentration of brightly sunlit natural water is 1X10-17 M(3), the half-life for this reaction would be 118 days(SRC). 2-Mercaptoethanol is not expected to undergo hydrolysis in the environment due to the lack of hydrolyzable functional groups(4). 2-Mercaptoethanol does not contain chromophores that absorb at wavelengths >290 nm and therefore is not expected to be susceptible to direct photolysis by sunlight(SRC).

An estimated BCF of 3.0 was calculated for 2-mercaptoethanol(SRC), using an estimated log Kow of -0.20(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 2-mercaptoethanol can be estimated to be 1.3(SRC). According to a classification scheme(2), this estimated Koc value suggests that 2-mercaptoethanol is expected to have very high mobility in soil.

The Henry's Law constant for 2-mercaptoehtanol is estimated as 1.8X10-7 atm-cu m/mole(SRC) derived from its vapor pressure, 1.76 mm Hg(1), and an assigned value for water solubility of 1.00X10+6 mg/L (miscible)(2). This Henry's Law constant indicates that 2-mercaptoethanol is expected to be essentially nonvolatile from water surfaces(3). 2-Mercaptoethanol's estimated Henry's Law constant indicates that volatilization from moist soil surfaces may not occur(SRC). 2-Mercaptoethanol is expected to volatilize from dry soil surfaces(SRC) based upon its extrapolated vapor pressure(1).

2-Mercaptoethanol and other thiol concentrations of less than 100 uM were detected in intertidal marine sediments from Biscayne Bay, FL(1); the presence of the thiols was attributed to protein degradation, where the protein source was marine algae and other higher plants(1).

2-Mercaptoethanol concentrations of 0.01 ppb or less were detected in samples of German wines(1).

NIOSH (NOES Survey 1981-1983) has statistically estimated that 14,140 workers (4,607 of these are female) are potentially exposed to 2-mercaptoethanol in the US(1). Occupational exposure to 2-mercaptoethanol may occur through inhalation and dermal contact with this compound at workplaces where 2-mercaptoethanol is produced or used(SRC). Monitoring data indicate that the general population may be exposed to 2-mercaptoethanol via dermal contact with this compound and other products containing 2-mercaptoethanol(SRC).

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.

/GUIDE 153: SUBSTANCES - TOXIC and/or CORROSIVE (Combustible)/ Fire or Explosion: Combustible material: may burn but does not ignite readily. When heated, vapors may form explosive mixtures with air: indoors, outdoors and sewers explosion hazards. Those substances designated with a (P) may polymerize explosively when heated or involved in a fire. Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated. Runoff may pollute waterways. Substance may be transported in a molten form.

/GUIDE 153: SUBSTANCES - TOXIC and/or CORROSIVE (Combustible)/ Health: TOXIC; inhalation, ingestion or skin contact with material may cause severe injury or death. Contact with molten substance may cause severe burns to skin and eyes. Avoid any skin contact. Effects of contact or inhalation may be delayed. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution.

/GUIDE 153: SUBSTANCES - TOXIC and/or CORROSIVE (Combustible)/ 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 in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids. Keep unauthorized personnel away. Stay upwind. Keep out of low areas. Ventilate enclosed areas.

/GUIDE 153: SUBSTANCES - TOXIC and/or CORROSIVE (Combustible)/ Protective Clothing: Wear positive pressure self-contained breathing apparatus (SCBA). Wear chemical protective clothing that is specifically recommended by the manufacturer. It may provide little or no thermal protection. Structural firefighters' protective clothing provides limited protection in fire situations ONLY; it is not effective in spill situations where direct contact with the substance is possible.

For more DOT Emergency Guidelines (Complete) data for 2-MERCAPTOETHANOL (8 total), please visit the HSDB record page.

UN 2966; Thioglycol

IMO 6.1; Thioglycol

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.

Do not transport with food and feedstuffs.

UN Hazard Class: 6.1; UN Pack Group: I