2-butyne-1,4-diol

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

H312: Harmful in contact with skin [Warning Acute toxicity, dermal]

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

H317: May cause an allergic skin reaction [Warning Sensitization, Skin]

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

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

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

H301 (100%): Toxic if swallowed [Danger Acute toxicity, oral]

H311 (48.9%): Toxic in contact with skin [Danger Acute toxicity, dermal]

H312 (57.7%): Harmful in contact with skin [Warning Acute toxicity, dermal]

H314 (100%): Causes severe skin burns and eye damage [Danger Skin corrosion/irritation]

H317 (100%): May cause an allergic skin reaction [Warning Sensitization, Skin]

H318 (45.2%): Causes serious eye damage [Danger Serious eye damage/eye irritation]

H331 (99.7%): Toxic if inhaled [Danger Acute toxicity, inhalation]

H335 (41%): May cause respiratory irritation [Warning Specific target organ toxicity, single exposure; Respiratory tract irritation]

H373 (99.7%): May causes damage to organs through prolonged or repeated exposure [Warning Specific target organ toxicity, repeated exposure]

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

Aggregated GHS information provided per 376 reports by companies from 23 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.

H311: Toxic in contact with skin [Danger Acute toxicity, dermal]

H318: Causes serious eye damage [Danger Serious eye damage/eye irritation]

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

H372: Causes damage to organs through prolonged or repeated exposure [Danger Specific target organ toxicity, repeated exposure]

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

P260, P261, P262, P264, P264+P265, P270, P271, P272, P280, P301+P316, P301+P330+P331, P302+P352, P302+P361+P354, P304+P340, P305+P354+P338, P308+P316, P316, P317, P319, P321, P330, P333+P317, P361+P364, P362+P364, P363, P403+P233, P405, and P501 (click each P-code to see the statement)

Fresh air, rest. Half-upright position. Refer immediately for medical attention.

Remove contaminated clothes. Rinse and then wash skin with water and soap. Refer immediately for medical attention.

Rinse with plenty of water (remove contact lenses if easily possible). Refer immediately for medical attention.

Rinse mouth. Do NOT induce vomiting. Refer immediately for medical attention.

SKIN CONTACT: wash affected skin area thoroughly with water.

EYE CONTACT: immediately wash with water for at least 15 minutes and get medical attention. (USCG, 1999)

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.

Fire Extinguishing Agents: Water, alcohol foam, dry chemical, or carbon dioxide (USCG, 1999)

Use water spray, alcohol-resistant foam, dry powder, carbon dioxide.

If material on fire or involved in fire: Do not extinguish fire unless flow can be stopped. Use water in flooding quantities as fog. Solid streams fo water may be ineffective Cool all affected containers with flooding quantities of water. Use "alcohol" foam, dry chemical or carbon dioxide. Keep run-off water out of sewers and water sources.

· 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.

Evacuate danger area! Consult an expert! Personal protection: chemical protection suit including self-contained breathing apparatus. Do NOT let this chemical enter the environment. Sweep spilled substance into covered containers. If appropriate, moisten first to prevent dusting. Carefully collect remainder. Then store and dispose of according to local regulations.

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: Local exhaust ventilation should be applied wherever there is an incidence of point source emissions or dispersion of regulated contaminants in the work area. Ventilation control of the contaminant as close to its point of generation is both the most economical and safest method to minimize personnel exposure to airborne contaminants.

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.

Personnel protection: Avoid breathing vapors. Keep upwind. ... Do not handle broken packages unless wearing appropriate personal protective equipment. If contact with the material anticipated, wear appropriate chemical protective clothing.

If material not on fire and not involved in fire: Keep sparks, flames, and other sources of ignition away. Keep material out of water sources and sewers. Build dikes to contain flow as necessary. Attempt to stop leak if without undue personnel hazard. Use water spray to knock-down vapors.

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 incompatible materials. See Chemical Dangers. Cool. Store in an area without drain or sewer access.

The storage temperature should be kept below 40 °C and storage times longer than a few months should be avoided because the butynediol flakes tend to set up.

... MATERIALS WHICH ARE TOXIC AS STORED OR WHICH CAN DECOMP INTO TOXIC COMPONENTS DUE TO CONTACT WITH HEAT, MOISTURE, ACIDS, OR ACID FUMES, SHOULD BE STORED IN COOL, WELL-VENTILATED PLACE, OUT OF DIRECT RAYS OF SUN, AWAY FROM AREAS OF ... FIRE HAZARD & SHOULD BE PERIODICALLY INSPECTED & MONITORED.

· 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.

0.1 [ppm]

1.1 [mg/m3]

3.4 [mg/m3]

21 [mg/m3]

0.5 mg/m

0.36 mg/m

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.

A harmful contamination of the air will not or will only very slowly be reached on evaporation of this substance at 20 °C; on spraying or dispersing, however, much faster.

Corrosive. Inhalation may cause lung oedema, but only after initial corrosive effects on eyes and/or airways have become manifest. Medical observation is indicated.

The substance may have effects on the blood. This may result in anaemia. The substance may have effects on the kidneys and liver. This may result in tissue lesions. Repeated or prolonged contact may cause skin sensitization.

Neoprene rubber gloves and safety goggles or face shield. (USCG, 1999)

Neoprene rubber gloves and safety goggles or face shield

NO open flames.

STRICT HYGIENE!

Use ventilation (not if powder).

Protective clothing. Protective gloves.

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

Do not eat, drink, or smoke during work. Wash hands before eating.

1,4-butynediol appears as white to light-brown solid or brownish-yellow aqueous solution. Solid sinks and mixes with water. (USCG, 1999)

Liquid; Liquid; Other Solid; Other Solid

White to yellow solid; [HSDB] Yellow or amber colored chips or chunks; [MSDSonline]

YELLOW SOLID IN VARIOUS FORMS.

Plates from benzene and ethyl acetate

White, orthorhombic crystals

WHITE TO LIGHT YELLOW

Yellow scaley solid at 20 °C and 1,013 hPa

460 °F at 760 mmHg (USCG, 1999)

No boiling point at normal pressure; decomposes at >160 °C

238 °C @760 [mm Hg]

263 °F (USCG, 1999)

263 °F (OPEN CUP)

Insoluble in benzene; slightly soluble in ethyl ether, choroform; very soluble in ethanol, acetone, methanol

Soluble in aqueous acids.

In water, 3.74X10+6 mg/L at 25 °C

Solubility in water, g/100ml at 20 °C: 75 (good)

1.07 at 68 °F (USCG, 1999) - Denser than water; will sink

Relative density = 1.115 at 20 °C

Relative density (water = 1): 1.1

1.115 @ 20°C

Relative vapor density (air = 1): 3.0

0.000556 [mmHg]

5.56X10-4 mm Hg at 25 °C

Vapor pressure, Pa at 20 °C: 0.2

When heated to decomposition it emits acrid smoke and fumes and may explode.

58.9 mN/m at 30.8 °C (50% aqueous solution)

Iindex of refraction: 1.4804 at 20 °C/D

SOLN IS STRAW TO AMBER COLOR

Boiling point

Diamagnetic susceptibility

Heat of sublimation

Magnetic susceptibility

Optical coefficient

Refractive index

Thermal expansion coefficient

Vapor pressure

Viscosity

Other Classes -> Other Organic Compounds

Reactive agents - 1st degree

Soluble in water.

Alcohols and Polyols

Alkynes, with No Acetylenic Hydrogen

Water and Aqueous Solutions

Pure 1,4-BUTYNEDIOL is non-explosive. Small amounts of certain impurities-alkali hydroxides, alkaline earth hydroxides, halides-may cause explosive decomposition upon distillation. Butynediol should not be treated with basic catalysts in the absence of a solvent at room temperature, and its stability is less with elevated temperatures. In strong acids, contamination with mercury salts can also result in violent decomposition. [NFPA 491M 1991].

The pure diol may be distilled unchanged, but traces of alkali or alkaline earth hydroxides or halides may cause explosive decomposition during distillation. In presence of strong acids, mercury salts may cause violent decomposition of the diol.

The substance can be absorbed into the body by inhalation, through the skin and by ingestion. Serious local effects by all routes of exposure.

Cough. Sore throat. Burning sensation. Shortness of breath. Laboured breathing.

Redness. Pain. Skin burns.

Redness. Pain. Burns.

Burns in mouth and throat. Burning sensation in the throat and chest. Abdominal 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.

Reproductive Toxin - A chemical that is toxic to the reproductive system, including defects in the progeny and injury to male or female reproductive function. Reproductive toxicity includes developmental effects. See Guidelines for Reproductive Toxicity Risk Assessment.

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) = 150 mg/m3/2h

LD50 Guniea pig oral 130 mg/kg

LD50 Rabbit oral 150 mg/kg

LD50 Mouse oral 105 mg/kg

LD50 Rat oral 104 mg/kg

For more Non-Human Toxicity Values (Complete) data for 1,4-BUTYNEDIOL (9 total), please visit the HSDB record page.

Toxic action of 1,4-butynediol was prevented by pretreatment with pyrazole which competitively inhibited oxidation of 1,4-butynediol by rat liver alcohol dehydrogenase indicating that toxicity is due to products of oxidative metabolism.

Basic Treatment: Establish a patent airway (oropharyngeal or nasopharyngeal airway, if needed). 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 shock and treat if necessary ... . 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 0.9% saline (NS) during transport ... . Do not use emetics. For ingestion, rinse mouth and administer 5 ml/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 ... . /Higher alcohols (>3 carbons) and related compounds/

Advanced Treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in severe respiratory distress. Positive-pressure ventilation techniques, with a bag-valve-mask device, may be beneficial. Consider drug therapy for pulmonary edema ... . Monitor cardiac rhythm and treat arrhythmias as necessary ... . Start IV administration of D5W /SRP: "To keep open", minimal flow rate/. Use 0.9% saline (NS) or lactated Ringer's (LR) if signs of hypovolemia are present. For hypotension with signs of hypovolemia, administer fluid cautiously. Consider vasopressors if patient is hypotensive with a normal fluid volume. Watch for signs of fluid overload ... . Monitor for signs of hypoglycemia (decreased LOC, tachycardia, pallor, dilated pupils, diaphoresis, and/or dextrose strip or glucometer readings below 50 mg) and administer 50% dextrose if necessary ... . Treat seizures with diazepam or lorazepam ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Higher alcohols (>3 carbons) and related compounds/

/HUMAN EXPOSURE STUDIES/ Ten workers with suspicion of allergic contact eczema who were probably accidentally exposed to butynediol were asked for voluntary patch testing for possible sensitisation; 6 of these 10 workers were willing to undergo the test. Pure butynediol and technical grade butynediol were applied as a 0.5% aqueous solution. Furthermore, formaldehyde which is a precursor for synthesis and an impurity in technical grade butynediol was also tested. Whereas formaldehyde did not show a positive reaction in these individuals, 4/4 tested in 2001 showed clear evidence of sensitisation. Two other workers tested in 1990 and 1994 had positive patch test reactions ...

/SIGNS AND SYMPTOMS/ ... Reported to be severely irritating to eyes and to penetrate skin and cause severe irritation.

/CASE REPORTS/ A 20-year old patient whose occupation involved nickel-plating developed itchy dermatitis on the dorsum of his left hand, extending to the upper arm. By patch testing butynediol (1% in water) was identified as the causative agent ...

/CASE REPORTS/ A 54-yr old male worker developed an itchy dermatitis on his hands and lower arms. Eczematous eruption was seen and contact allergy suspected. He was patch tested. The only substance to give a two plus positive reaction at 48 hr was a 2% butin diol soln in water. At the 72 hr reading, the reaction had increased in severity.

/CASE REPORTS/ A 41-year-old female cleaner developed dermatitis on the face, hands and forearms after having used a new cleaning agent for a few months. The dermatitis appeared about 12 hours after contact with the agent and settled when she was not using it. Patch testing with the components of the cleaning agent produced a strong reaction to butynediol. The compound was present in the cleaning agent at low concentration (0.7%) as corrosion inhibitor. Patch testing of 55 control persons with 1% butynediol in water was negative ...

/LABORATORY ANIMALS: Acute Exposure/ ... Butynediol aerosol at concentrations of 0, 25, 100 and 300 mg/cu m was head-nose exposed on 5 days (6 hours/day) to five Wistar rats of each sex per group ... The 300 mg/ u m concentration was lethal for one animal of each sex during the exposure period (on study day 2 and 3). Clinical findings were confined to this concentration. They consisted in signs of upper respiratory tract irritation (bloody nasal crusts, accelerated respiration) and reduction of general health (piloerection, tremor, squatting posture). Urine samples of males and females exposed to 300 mg/cu m were discoloured from dark yellow to light orange. Body weight development was slightly retarded in the male and female animals. The body weight gain in these animals was significantly reduced compared to the control animals. Clinical pathology showed increased gamma-GT activities, bilirubin and cholesterol levels and decreased urea levels in the serum of both sexes. Increased levels of urobilinogen were detected in the urine of male and female animals. The two animals that died prematurely showed mucosal erosions/ulcers in the glandular stomach (male and female), erosions/ulcers of the forestomach and prominent acinar pattern in the liver, black red discoloration of the jejunal content, and few red brown foci in the adrenal cortex (female). No abnormal gross findings were observed in the remainder animals of the 300 mg/cu m groups. Histopathology of the liver revealed slight to moderate single cell necrosis (four females), liver cell dystrophy (two males and one female) and increased mitotic figures (one female). Inflammation and/or epithelial changes in nasal cavity and/or larynx were present in all animals of the high dose groups. They consisted of hyperaemia, increased/bloody mucus deposition, purulent rhinitis, focal unilateral or bilateral disarrangement of the olfactory epithelium (at levels III and IV of the nasal cavity), or atrophy of olfactory epithelium in the nasal cavity (one male only). Mixed cellular inflammation, hyperplasia and focal/diffuse metaplasia of the transitional epithelium of the larynx. Focal disarrangement of the olfactory epithelium occurred at levels III and IV of the nasal cavity; they were characterised by the loss of polar arrangement of the nuclei and by reduced/missing cytoplasma at the apical cell rim. Microscopic findings in the premature died animals were: congestion of liver, nasal cavity, lungs, kidneys, mediastinal lymph nodes, severe liver dystrophy, vacuolar degeneration and dystrophic calcification of the cortico-medullary area in the kidneys, severe lymphocytic necrosis in the thymus, severe lymphocytic depletion in the spleen, erosions/ulceration in the glandular stomach and/or forestomach, increased mucus in the nasal cavity, disarrangement of the olfactory epithelium, inflammation in the epiglottis (larynx level I), and blood resorption in the mediastinal lymph nodes. At 100 mg/cu m butynediol increased urobilinogen levels in urine, inflammation, increased/bloody mucus, focal disarrangement of olfactory epithelium in the nasal cavity, and inflammation, hyperplasia and focal/diffuse metaplasia of the laryngeal mucosa were observed. The 25 mg/cu m butynediol concentration caused a higher incidence of increased urobilinogen levels in urine incidence as well as increased/bloody mucus in the nasal cavity, inflammation and metaplasia of the laryngeal mucosa.[European Chemicals Bureau; European Union Risk Assessment Report, BUT-2YNE-1,4-DIOL (CAS No: 110-65-6) (2005). Available from, as of September 13, 2006: http://esis.jrc.ec.europa.eu/]

/LABORATORY ANIMALS: Acute Exposure/ Intense hypothermic action of 1,4-butynediol (7.0 °Fall in body temp 2 hr after injection of 0.609 to 0.635 mmol/kg ip) was not itself cause of death, but toxicity due to products of oxidative metabolites.[TABERNER PV, PEARCE MJ; J PHARM PHARMACOL 26 (8): 597 (1974)]

/LABORATORY ANIMALS: Acute Exposure/ ... /1,4-butynediol/ has not shown any skin sensitising effects in a ... Magnusson Kligman test with 22 /guinea pigs/ ... in the test group and 8 animals in control group, using an intradermal induction of 2%, topical induction with 20% and challenge with 5% and 20% butynediol.[European Chemicals Bureau; European Union Risk Assessment Report, BUT-2YNE-1,4-DIOL (CAS No: 110-65-6) (2005). Available from, as of September 13, 2006: http://esis.jrc.ec.europa.eu/]

/LABORATORY ANIMALS: Acute Exposure/ Acute toxicity after a single 4-hour inhalative exposure (head-nose inhalation system) to butynediol (liquid aerosol of aqueous solutions, MMAD 0.5 to 1.0 um) has been tested recently in an acute inhalation toxicity study with rats: No male but 4/5 female rats died after exposure to 0.69 mg/L, all animals died at 1.03 mg/L ... The predominant effects at necropsy were red discoloration in lungs and light brown discoloration in livers, erosion/ulceration of glandular stomach or general congestion. Irregular and accelerated respiration was observed in all groups up to one day after exposure.[European Chemicals Bureau; European Union Risk Assessment Report, BUT-2YNE-1,4-DIOL (CAS No: 110-65-6) (2005). Available from, as of September 11, 2006: http://esis.jrc.ec.europa.eu/]

For more Non-Human Toxicity Excerpts (Complete) data for 1,4-BUTYNEDIOL (36 total), please visit the HSDB record page.

EC50 Daphnia magna 26.8 mg/L48 hr (nominal concentration) immobilization, static test. NOTE: At 100 mg/L all daphnids were immobile after 48 hours.

LC50 Pimephales promelas (Fathead minnow) 53.6 mg/L/96 hr (confidence limit 49.3-58.3 mg/L), flow-through bioassay with measured concentrations, 25.1 °C, dissolved oxygen 6.8 mg/L, hardness 46.5 mg/L calcium carbonate, alkalinity 43.5 mg/L calcium carbonate, and pH 7.7

EC50 Pimephales promelas (Fathead minnow) 53.6 mg/L/96 hr (confidence limit 49.3-58.3 mg/L), flow-through bioassay with measured concentrations, 25.1 °C, dissolved oxygen 6.8 mg/L, hardness 46.5 mg/L calcium carbonate, alkalinity 43.5 mg/L calcium carbonate, and pH 7.7. Effect: loss of equilibrium was not observed prior to death.

LC50 Leuciscus idus (fresh-water cyprinoid fish) 46 mg/L/96 hr /Conditions of bioassay not specified in source examined/

For more Ecotoxicity Values (Complete) data for 1,4-BUTYNEDIOL (7 total), please visit the HSDB record page.

/AQUATIC SPECIES/ ... The test results on /the freshwater fish/ Leuciscus idus /showed that among/ the selected test concentrations (10, 21.5, 46.4 and 100 mg/L) only at the highest two lethal effects were observed. After 96 hours the mortality was 5% at 46.4 mg/L and 100% at 100 mg/L and therefore the LC50 is between 46.4 and 100 mg/Ll. The NOEC was 21.5 mg/L.

/AQUATIC SPECIES/ The population growth impairment testing was done in the /protozoa/ Tetrahymena pyriformis batch system ... This is a two-day assay using population density measured spectrophotometrically at 540 nm as the endpoint. An EC50 inhibition of growth of 1,343 mg/L after 48 hours was obtained.

/AQUATIC SPECIES/ In a test ... with /the freshwater algae/ Scenedesmus subspicatus after 96 hours an EC50 of 433 mg/L and an EC20 of 218 mg/L were derived for the reduction of biomass measured fluorometrically.

/AQUATIC SPECIES/ Using continuous flow diluters, the 96 hr LC50 values were determined for 16 acetylenic alcohols in the fathead minnow (Pimephales promelas). The observed LC50 value for butyn-1,4-diol was 53.6 (49.3-58.3) mg/L. This was 4740 times greater than the predicted LC50 of 254,000 mg/L based on quantitative structure activity relationships (QSAR) for ... /CNS depressant/ lethality.

/OTHER TERRESTRIAL SPECIES/ In a test with /the soil bacterium/ Pseudomonas putida ... after 17 hours an EC50 of 3,935 mg/L and an EC10 of 1993 were obtained for cell multiplication inhibition measured at 436 nm.

EC50 Daphnia magna 26.8 mg/L48 hr (nominal concentration) immobilization, static test. NOTE: At 100 mg/L all daphnids were immobile after 48 hours.

LC50 Pimephales promelas (Fathead minnow) 53.6 mg/L/96 hr (confidence limit 49.3-58.3 mg/L), flow-through bioassay with measured concentrations, 25.1 °C, dissolved oxygen 6.8 mg/L, hardness 46.5 mg/L calcium carbonate, alkalinity 43.5 mg/L calcium carbonate, and pH 7.7

EC50 Pimephales promelas (Fathead minnow) 53.6 mg/L/96 hr (confidence limit 49.3-58.3 mg/L), flow-through bioassay with measured concentrations, 25.1 °C, dissolved oxygen 6.8 mg/L, hardness 46.5 mg/L calcium carbonate, alkalinity 43.5 mg/L calcium carbonate, and pH 7.7. Effect: loss of equilibrium was not observed prior to death.

LC50 Leuciscus idus (fresh-water cyprinoid fish) 46 mg/L/96 hr /Conditions of bioassay not specified in source examined/

For more Ecotoxicity Values (Complete) data for 1,4-BUTYNEDIOL (7 total), please visit the HSDB record page.

/AQUATIC SPECIES/ ... The test results on /the freshwater fish/ Leuciscus idus /showed that among/ the selected test concentrations (10, 21.5, 46.4 and 100 mg/L) only at the highest two lethal effects were observed. After 96 hours the mortality was 5% at 46.4 mg/L and 100% at 100 mg/L and therefore the LC50 is between 46.4 and 100 mg/Ll. The NOEC was 21.5 mg/L.

/AQUATIC SPECIES/ The population growth impairment testing was done in the /protozoa/ Tetrahymena pyriformis batch system ... This is a two-day assay using population density measured spectrophotometrically at 540 nm as the endpoint. An EC50 inhibition of growth of 1,343 mg/L after 48 hours was obtained.

/AQUATIC SPECIES/ In a test ... with /the freshwater algae/ Scenedesmus subspicatus after 96 hours an EC50 of 433 mg/L and an EC20 of 218 mg/L were derived for the reduction of biomass measured fluorometrically.

/AQUATIC SPECIES/ Using continuous flow diluters, the 96 hr LC50 values were determined for 16 acetylenic alcohols in the fathead minnow (Pimephales promelas). The observed LC50 value for butyn-1,4-diol was 53.6 (49.3-58.3) mg/L. This was 4740 times greater than the predicted LC50 of 254,000 mg/L based on quantitative structure activity relationships (QSAR) for ... /CNS depressant/ lethality.

/OTHER TERRESTRIAL SPECIES/ In a test with /the soil bacterium/ Pseudomonas putida ... after 17 hours an EC50 of 3,935 mg/L and an EC10 of 1993 were obtained for cell multiplication inhibition measured at 436 nm.

The substance is harmful to aquatic organisms.

1,4-Butynediol's production and use as an intermediate, corrosion inhibitor, electroplating brightener, polymerization accelerator, stabilizer for chlorinated hydrocarbons and cosolvent for paint and varnish removal may result in its release to the environment through various waste streams. Its use as a defoliant (not registered for this application in the US) will result in its direct release to the environment. If released to air, a vapor pressure of 5.56X10-4 mm Hg at 25 °C indicates 1,4-butynediol will exist solely as a vapor in the atmosphere. Vapor-phase 1,4-butynediol 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 11 hours. 1,4-Butynediol 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, 1,4-butynediol is expected to have very high mobility based upon a estimated Koc of 1. Volatilization from moist soil surfaces is not expected to be an important fate process based upon an estimated Henry's Law constant of 1.7X10-11 atm-cu m/mole. 1,4-Butynediol has been shown to biodegrade 90% in 4 days using a sewage sludge; therefore, biodegradation is expected to be important in soil and water. If released into water, 1,4-butynediol 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 0.12 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 1,4-butynediol may occur through dermal contact with this compound at workplaces where 1,4-butynediol is produced or used. The general population may be exposed to 1,4-butynediol via dermal contact with products containing 1,4-butynediol. (SRC)

1,4-Butynediol's production and use as an intermediate, corrosion inhibitor, electroplating brightener, polymerization accelerator, stabilizer for chlorinated hydrocarbons and cosolvent for paint and varnish removal(1) may result in its release to the environment through various waste streams. Its use as a defoliant(1) (not regristered for this application in the US(2)) will result in its direct release to the environment(SRC).

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 1(SRC), determined from a water solubility of 3.74X10+6 mg/L(2) and a regression-derived equation(3), indicates that 1,4-butynediol is expected to have very high mobility in soil(SRC). Volatilization of 1,4-butynediol from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 1.7X10-11 atm-cu m/mole(SRC), derived from its vapor pressure, 5.56X10-4 mm Hg(4), and water solubility(2). 1,4-Butynediol is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(4). 1,4-Butynediol has been shown to biodegrade 90% in 4 days using a sewage sludge(5); therefore, biodegradation is expected to be an important environmental fate process in soil(SRC).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 1(SRC), determined from a water solubility of 3.74X10+6 mg/L(2) and a regression-derived equation(3), indicates that 1,4-butynediol 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 1.7X10-11 atm-cu m/mole(SRC), derived from its vapor pressure, 5.56X10-4 mm Hg(4), and its water solubility(2). According to a classification scheme(5), an estimated BCF of 0.12(SRC), from its water solubility(2) and a regression-derived equation(3), suggests the potential for bioconcentration in aquatic organisms is low(SRC). 1,4-Butynediol has been shown to biodegrade 90% in 4 days using a sewage sludge(6); therefore, biodegradation is expected to be an important environmental fate profcess in water(SRC).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), 1,4-butynediol, which has a vapor pressure of 5.56X10-4 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase 1,4-butynediol 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 11 hours(SRC), calculated from its rate constant of 3.4X10-11 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). 1,4-Butynediol does not contain chromophores that absorb at wavelengths >290 nm and therefore is not expected to be susceptible to direct photolysis by sunlight(4).

AEROBIC: Biodegradation of 1,4-butynediol was 90% complete in 4 days using an initial concentration of 500 mg/L and a sewage sludge inoculum concentration of 500 mg/L(1).

The rate constant for the vapor-phase reaction of 1,4-butynediol with photochemically-produced hydroxyl radicals has been estimated as 3.4X10-11 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 11 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). The rate constant for the vapor-phase reaction of 1,4-butynediol with ozone has been estimated as 3.0X10-20 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(1). This corresponds to an atmospheric half-life of about 382 days at an atmospheric concentration of 7X10+11 ozone molecules per cu cm(2). 1,4-Butynediol does not contain chromophores that absorb at wavelengths >290 nm and therefore is not expected to be susceptible to direct photolysis by sunlight(3).

An estimated BCF of 0.12 was calculated in fish for 1,4-butynediol(SRC), using a water solubility of 3.74X10+6 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 1,4-butynediol is estimated as 1(SRC), using a water solubility of 3.74X10+6 mg/L(1) and a regression-derived equation(2). According to a classification scheme(3), this estimated Koc value suggests that 1,4-butynediol is expected to have very high mobility in soil.

The Henry's Law constant for 1,4-butynediol is estimated as 1.7X10-11 atm-cu m/mole(SRC) derived from its vapor pressure, 5.56X10-4 mm Hg(1), and water solubility, 3.74X10+6 mg/L(2). This Henry's Law constant indicates that 1,4-butynediol is expected to be essentially nonvolatile from water surfaces(3). 1,4-Butynediol is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(1).

1,4-Butynediol was reported at 5304 ng/uL of extract in 1 occurrence from the organics and plastics industry(1).

NIOSH (NOES Survey 1981-1983) has statistically estimated that 16,528 workers (4,756 of these are female) are potentially exposed to 1,4-butynediol in the US(1). Occupational exposure to 1,4-butynediol may occur through dermal contact with this compound at workplaces where 1,4-butynediol is produced or used(SRC). The general population may be exposed to 1,4-butynediol via dermal contact with products containing 1,4-butynediol(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 1,4-BUTYNEDIOL (8 total), please visit the HSDB record page.

UN 2716; 1,4-Butynediol

IMO 6.1; 1,4-Butynediol

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.

Symbol: C, T; R: 21-23/25-34-43-48/22; S: (1/2)-25-26-36/37/39-45-46

UN Hazard Class: 6.1; UN Pack Group: III