cis-2-BUTENE

H220: Extremely flammable gas [Danger Flammable gases]

P203, P210, P222, P280, P377, P381, and P403 (click each P-code to see the statement)

H220 (100%): Extremely flammable gas [Danger Flammable gases]

H280 (80.7%): Contains gas under pressure; may explode if heated [Warning Gases under pressure]

H336 (11.7%): May cause drowsiness or dizziness [Warning Specific target organ toxicity, single exposure; Narcotic effects]

P203, P210, P222, P261, P271, P280, P304+P340, P319, P377, P381, P403, P403+P233, P405, P410+P403, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 891 reports by companies from 7 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.

H280 (87.9%): Contains gas under pressure; may explode if heated [Warning Gases under pressure]

P203, P210, P222, P280, P377, P381, P403, and P410+P403 (click each P-code to see the statement)

Aggregated GHS information provided per 605 reports by companies from 8 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

H280: Contains gas under pressure; may explode if heated [Warning Gases under pressure]

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

ON FROSTBITE: rinse with plenty of water, do NOT remove clothes. Refer for medical attention .

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

Excerpt from ERG Guide 115 [Gases - Flammable (Including Refrigerated Liquids)]:

Refer to the "General First Aid" section. Specific First Aid: Clothing frozen to the skin should be thawed before being removed. In case of contact with liquefied gas, only medical personnel should attempt thawing frosted parts. In case of burns, immediately cool affected skin for as long as possible with cold water. Do not remove clothing if adhering to skin. (ERG, 2024)

Excerpt from ERG Guide 115 [Gases - Flammable (Including Refrigerated Liquids)]:

DO NOT EXTINGUISH A LEAKING GAS FIRE UNLESS LEAK CAN BE STOPPED. CAUTION: Hydrogen (UN1049), Deuterium (UN1957), Hydrogen, refrigerated liquid (UN1966) and Hydrogen and Methane mixture, compressed (UN2034) will burn with an invisible flame. Use an alternate method of detection (thermal camera, broom handle, etc.).

SMALL FIRE: Dry chemical or CO2.

LARGE FIRE: Water spray or fog. If it can be done safely, move undamaged containers away from the area around the fire. CAUTION: For LNG - Liquefied natural gas (UN1972) pool fires, DO NOT USE water. Use dry chemical or high-expansion foam.

FIRE INVOLVING 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. Do not direct water at source of leak or safety devices; icing may occur. 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)

Shut off supply; if not possible and no risk to surroundings, let the fire burn itself out. In other cases extinguish with water spray, dry powder, alcohol-resistant foam. In case of fire: keep cylinder cool by spraying with water. Combat fire from a sheltered position.

Suitable extinguishing media: Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide. Advice for firefighters: Wear self-contained breathing apparatus for firefighting if necessary. Further information: Use water spray to cool unopened containers.

Very dangerous fire hazard when exposed to heat or flame ... To fight fire, stop flow of gas.

Suitable extinguishing media: Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide.

Advice for firefighters: Wear self-contained breathing apparatus for firefighting if necessary.

Special hazards arising from the substance or mixture: Carbon oxides

Excerpt from ERG Guide 115 [Gases - Flammable (Including Refrigerated Liquids)]:

IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area for at least 100 meters (330 feet) in all directions.

LARGE SPILL: Consider initial downwind evacuation for at least 800 meters (1/2 mile).

FIRE: If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 1600 meters (1 mile) in all directions; also, consider initial evacuation for 1600 meters (1 mile) in all directions. In fires involving Liquefied Petroleum Gases (LPG) (UN1075), Butane (UN1011), Butylene (UN1012), Isobutylene (UN1055), Propylene (UN1077), Isobutane (UN1969), and Propane (UN1978), also refer to the "BLEVE - Safety Precautions" section. (ERG, 2024)

Evacuate danger area! Consult an expert! Personal protection: self-contained breathing apparatus. Remove all ignition sources. Shut off cylinder if possible. Ventilation. Isolate the area until the gas has dispersed. NEVER direct water jet on liquid.

ACCIDENTAL RELEASE MEASURES: Personal precautions, protective equipment and emergency procedures: Avoid breathing vapors, mist or gas. Ensure adequate ventilation. Remove all sources of ignition. Evacuate personnel to safe areas. Beware of vapors accumulating to form explosive concentrations. Vapors can accumulate in low areas. Environmental precautions: Prevent further leakage or spillage if safe to do so. Do not let product enter drains. Methods and materials for containment and cleaning up: Clean up promptly by sweeping or vacuum.

SRP: 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 air, soil or water; effects on animal, aquatic and plant life; and conformance with environmental and public health regulations. If it is possible or reasonable use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination.

Product: Burn in a chemical incinerator equipped with an afterburner and scrubber but exert extra care in igniting as this material is highly flammable. Offer surplus and non-recyclable solutions to a licensed disposal company. Contact a licensed professional waste disposal service to dispose of this material. Contaminated packaging: Dispose of as unused product.

Gloves must be inspected prior to use. Use proper glove removal technique (without touching glove's outer surface) to avoid skin contact with this product. Dispose of contaminated gloves after use in accordance with applicable laws and good laboratory practices. Wash and dry hands.

Avoid inhalation of vapor or mist. Use explosion-proof equipment. Keep away from sources of ignition - No smoking. Take measures to prevent the build up of electrostatic charge.

ACCIDENTAL RELEASE MEASURES: Personal precautions, protective equipment and emergency procedures: Avoid breathing vapors, mist or gas. Ensure adequate ventilation. Remove all sources of ignition. Evacuate personnel to safe areas. Beware of vapors accumulating to form explosive concentrations. Vapors can accumulate in low areas. Environmental precautions: Prevent further leakage or spillage if safe to do so. Do not let product enter drains.

Handle in accordance with good industrial hygiene and safety practice. Wash hands before breaks and at the end of workday.

SRP: The scientific literature for the use of contact lenses by industrial workers is inconsistent. The benefits 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.

Precautions for safe handling: Avoid inhalation of vapor or mist. Use explosion-proof equipment. Keep away from sources of ignition - No smoking. Take measures to prevent the build up of electrostatic charge.

Appropriate engineering controls: Handle in accordance with good industrial hygiene and safety practice. Wash hands before breaks and at the end of workday.

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.

Excerpt from ERG Guide 115 [Gases - Flammable (Including Refrigerated Liquids)]:

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. If possible, turn leaking containers so that gas escapes rather than liquid. Use water spray to reduce vapors or divert vapor cloud drift. Avoid allowing water runoff to contact spilled material. Do not direct water at spill or source of leak. CAUTION: For LNG - Liquefied natural gas (UN1972), DO NOT apply water, regular or alcohol-resistant foam directly on spill. Use a high-expansion foam if available to reduce vapors. Prevent spreading of vapors through sewers, ventilation systems and confined areas. Isolate area until gas has dispersed. CAUTION: When in contact with refrigerated/cryogenic liquids, many materials become brittle and are likely to break without warning. (ERG, 2024)

Fireproof. Store outside or in a separate well-ventilated building. Ventilation along the floor.

Keep container tightly closed in a dry and well-ventilated place. Contents under pressure. Storage class (TRGS 510): Gases

750 [ppm]

2200 [ppm]

13000 [ppm]

8 hr Time Weighted Avg (TWA): 250 ppm. /Butenes, all isomers/

Peak Exposure Recommendation: Transient increases in workers' exposure levels may exceed 3 times the value of the TLV-TWA level for no more than 15 minutes at a time, on no more than 4 occasions spaced 1 hour apart during a workday, and under no circumstances should they exceed 5 times the value of the TLV-TWA level. In addition, the 8-hour TWA is not to be exceeded for an 8-hour work period. /Butenes, all isomers/

250 ppm as TWA

On loss of containment this substance can cause suffocation by lowering the oxygen content of the air in confined areas.

Rapid evaporation of the liquid may cause frostbite. Exposure to high concentrations could cause asphyxiation. This may result in unconsciousness, respiratory arrest and death.

Excerpt from ERG Guide 115 [Gases - Flammable (Including Refrigerated Liquids)]:

Wear positive pressure self-contained breathing apparatus (SCBA). Structural firefighters' protective clothing provides thermal protection but only limited chemical protection. Always wear thermal protective clothing when handling refrigerated/cryogenic liquids. (ERG, 2024)

Skin protection: Handle with gloves.

Eye/face protection: Face shield and safety glasses Use equipment for eye protection tested and approved under appropriate government standards such as NIOSH (US) or EN 166(EU).

Body Protection: Impervious clothing. Flame retardant antistatic protective clothing. The type of protective equipment must be selected according to the concentration and amount of the dangerous substance at the specific workplace.

Respiratory protection: Where risk assessment shows air-purifying respirators are appropriate use a full-face respirator with multipurpose combination (US) or type AXBEK (EN 14387) respirator cartridges as a backup to engineering controls. If the respirator is the sole means of protection, use a full-face supplied air respirator. Use respirators and components tested and approved under appropriate government standards such as NIOSH (US) or CEN (EU).

Eye/face protection: Face shield and safety glasses. Use equipment for eye protection tested and approved under appropriate government standards such as NIOSH (US) or EN 166(EU).

NO open flames, NO sparks and NO smoking. Closed system, ventilation, explosion-proof electrical equipment and lighting. Prevent build-up of electrostatic charges (e.g., by grounding) if in liquid state. Use non-sparking handtools. Flame arrester to prevent flash-back from burner to cylinder.

Use ventilation, local exhaust or breathing protection.

Cold-insulating gloves.

Wear face shield.

Do not eat, drink, or smoke during work.

2-butene appears as a colorless liquefied petroleum gas. Asphyxiate gas. Flammability limits in air 1.8-9.7% by volume.

Gas Vapor; Liquid

COLOURLESS COMPRESSED LIQUEFIED GAS.

Colorless gas

Flammable gas

Slightly aromatic odor

3.73 °C at 760 mm Hg /cis-2-Butene/

3.7 °C @760 [mm Hg]

-139.3 °C /cis-2-Butene/

-138.89 °C

-138.7 °C

-138.9 °C

-11.99 °C (10.42 °F) - closed cup

Very soluble in ethanol and ether. Soluble in benzene. /cis- and trans-2-Butene/

In water, 658 mg/L at 25 °C

Insoluble in water

Soluble in most organic solvents

Soluble in benzene; very soluble in alcohol, ether

Solubility in water, mg/l at 25 °C: 658 (very slightly soluble)

0.616 g/cu cm at 25 °C

Density (at the boiling point of the liquid): 0.6 kg/l

0.616 @25 °C

1.9 (Air = 1)

Relative vapor density (air = 1): 1.9

1600 mm Hg at 25 °C /cis-2-Butene/

Vapor pressure: 1410 mm Hg at 21 °C

Vapor pressure = 1360 mm Hg at 20 °C

1,600 mm Hg at 25 °C

Vapor pressure, kPa at 21 °C: 181

1600 [mm Hg] @25 °C

log Kow = 1.85 (mixture of 70% cis- and 30% trans-2-Butene)

log Kow = 2.33

Henry's Law constant = 0.231 atm-cu m/mole at 25 °C

Stable under recommended storage conditions.

617 °F (325 °C)

When heated to decomposition it emits acrid smoke and irritating vapors.

When heated to decomposition it emits acrid smoke and fumes.

0.00782 mPa

-2712 kJ/mol

22.17 kJ/mol

Highly flammable. Insoluble in water.

Hydrocarbons, Aliphatic Unsaturated

Highly Flammable

The unsaturated aliphatic hydrocarbons, such as 2-BUTENE, are generally much more reactive than the alkanes. Strong oxidizers may react vigorously with them. Reducing agents can react exothermically to release gaseous hydrogen. In the presence of various catalysts (such as acids) or initiators, compounds in this class can undergo very exothermic addition polymerization reactions. Aluminum borohydride reacts with alkenes and in the presence of oxygen, combustion is initiated even in the absence of moisture.

Incompatible materials: Strong oxidizing agents.

Incompatible with oxidizing materials.

IDENTIFICATION AND USE: 2-Butene is a colorless gas. It is used as a solvent and a cross-linking agent. It is also used to polymerize gasoline, and for butadiene synthesis, as well as the synthesis of derivatives. HUMAN STUDIES: 2-Butene is an asphyxiant gas. Rapid evaporation of liquid 2-butene may cause frostbite. it may cause effects on the CNS. Exposure may result in unconsciousness. ANIMAL STUDIES: Rats were exposed for 4 hr to 2-butene at a nominal concentration of 10,000 ppm (22,948 mg/cu m). No clinical signs were seen and normal growth occurred over the 14 d observation period. 2-Butene is a cardiac sensitizer in dogs. In developmental studies in rats, there were no effects on mating behavior, fertility and gestation indices, the number of implantation sites and corpora lutea per dam, numbers of pups delivered, viability of pups at and after birth and the pup sex ratio when compared to the control group. There were no treatment-related effects on the development of pups. Male and female rats were exposed to 2-butene at target concentrations of 2500 or 5000 ppm (5737 or 11,474 mg/cu m) for two weeks prior to breeding, during breeding (1 week) and until day 19 of gestation (39-46 days of exposure). No significant systemic toxicity occurred in either sex, or in pregnant female rats. 2-Butene is a CNS depressant. About 13 to 13.5% (300 or 400 mg/L) causes deep CNS depression, and in mice about 19% (120 to 420 mg/L) is fatal. It is a mild mucous membrane irritant. A chromosome aberration study was conducted with 2-butene in rat lymphocytes in vito. No significant increases were seen in the frequency of chromosome aberrations either in the presence or absence of a metabolic activation. 2-Butene was not mutagenic to S. typhimurium TA98, TA100, TA1535, TA 1537 and E.coli WP2uvrA, with or without metabolic activation.

IDENTIFICATION AND USE: cis-2-Butene is a colorless gas. It is used in solvents, as a cross-linking agent, in polymerization of gasoline, in butadiene synthesis, and in synthesis of C4 and C5 derivatives. HUMAN STUDIES: cis-2-Butene is a simple asphyxiant. Rapid evaporation of liquid 2-butene (in its cis or trans form, or as a mixture of both) may cause frostbite. The substance may cause effects on the central nervous system. Exposure may result in unconsciousness. ANIMAL STUDIES: There are no data available.

Exposure mainly occurs via inhalation.

Dizziness. Unconsciousness. Suffocation.

ON CONTACT WITH LIQUID: FROSTBITE.

See Skin.

LC50 Mice, inhalation 425 ppm /the duration of exposure is not stated/

Immediate first aid: Ensure that adequate decontamination has been carried out. If patient is not breathing, start artificial respiration, preferably with a demand valve resuscitator, bag-valve-mask device, or pocket mask, as trained. Perform CPR if necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on the left side (head-down position, if possible) to maintain an open airway and prevent aspiration. Keep patient quiet and maintain normal body temperature. Obtain medical attention. /Aliphatic hydrocarbons and related compounds/

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 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 ... . Treat frostbite with rapid rewarming techniques ... . /Aliphatic hydrocarbons 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. Watch for signs of fluid overload ... . Treat seizures with diazepam (Valium) or lorazepam (Ativan) ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Aliphatic hydrocarbons and related compounds/

/SIGNS AND SYMPTOMS/ Rapid evaporation of the 2-butene (in its cis or trans form, or a mixture of both) may cause frostbite. The substance may cause effects on the CNS. Exposure may result in unconsciousness.

/SIGNS AND SYMPTOMS/ A simple asphyxiant.

/SIGNS AND SYMPTOMS/ Rapid evaporation of the 2-butene (in its cis or trans form, or as a mixture of both) may cause frostbite. The substance may cause effects on the central nervous system. Exposure may result in unconsciousness.

/LABORATORY ANIMALS: Acute Exposure/ Rats were exposed for 4 hr to 2-butene at a nominal concentration of 10,000 ppm (22,948 mg/cu m). No clinical signs were seen and normal growth occurred over the 14 d observation period. No abnormalities were observed at gross necropsy. Only one concentration was tested. This concentration was at the explosive limit and therefore higher concentrations could not be tested.

/LABORATORY ANIMALS: Developmental or Reproductive Toxicity/ Male and female rats were exposed to 2-butene at target concentrations of 2500 or 5000 ppm (approximately 5750 or 11500 mg/cu m) for two weeks prior to breeding, during breeding and until day 19 of gestation. The dams were then allowed to deliver their litters, which were retained until postnatal day 4. Some decreases in body weight were observed in females at 2500 or 5000 ppm during the mating period but these were inconsistent and no other treatment-related changes were observed. There was no evidence of significant systemic toxicity in the parents. There were no effects on mating behavior, fertility and gestation indices, the number of implantation sites and corpora lutea per dam, numbers of pups delivered, viability of pups at and after birth and the pup sex ratio when compared to the control group. Microscopic evaluation of gonadal function in parental males revealed no difference between treated and control groups. There were no treatment-related effects on the development of pups. There were no effects on body weight gain or observed during macroscopic examination of pups at post mortem. Based on these data, the NOAEC for reproductive and developmental toxicity was 5000 ppm (11,500 mg/cu m), the highest concentration tested.

/LABORATORY ANIMALS: Developmental or Reproductive Toxicity/ Male and female rats were exposed to 2-butene at target concentrations of 2500 or 5000 ppm ( 5737 or 11474 mg/cu m) for two weeks prior to breeding, during breeding (1 week) and until day 19 of gestation (39-46 days of exposure). No significant systemic toxicity occurred in either sex, or in pregnant female rats. Some decreases in body weight were observed in both sexes at 5000 ppm but no other treatment-related changes were observed. Mean absolute organ weight and relative weight were comparable in all groups. No abnormal, treatment-related macroscopic changes (all groups) or pathological changes (control and 5000 ppm groups) were observed. In the original report a NOAEL for toxicity was set at 2,500 ppm based on the slight effects on body weights in males and females, and possibly food consumption in females. A re-analysis of the data by the Netherlands National Institute for Public Health and the Environment (2009) however, concluded that as these effects were not dose-related and not consistently present during the study, therefore the NOAEL for this study is 5000 ppm.

/LABORATORY ANIMALS: Neurotoxicity/ Concentrations of 13 to 13.5% (300 or 400 mg/L) causes deep CNS depression in mice and about 19% (120 to 420 mg/L) is fatal.

For more Non-Human Toxicity Excerpts (Complete) data for 2-Butene (8 total), please visit the HSDB record page.

2-Butene's production and use in the production of gasolines, butadiene and other chemicals may result in its release to the environment through various waste streams. If released to air, a vapor pressure of 1600 mm Hg at 25 °C indicates 2-butene will exist solely as a gas in the atmosphere. Gas-phase 2-butene 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 6.4 hours. Gas-phase 2-butene will be degraded in the atmosphere by reaction with ozone; the half-life for this reaction in air is estimated to be 0.64 to 6.4 hours. Gas-phase 2-butene will be degraded in the atmosphere by nighttime reaction with nitrate radicals; the half-life for this reaction in air is estimated to be 0.5 hours. 2-Butene 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-butene is expected to have very high mobility based upon an estimated Koc of 40. Volatilization from moist soil surfaces is expected to be an important fate process based upon an estimated Henry's Law constant of 1.54X10-1 atm-cu m/mole. 2-Butene may volatilize from dry soil surfaces based upon its vapor pressure. Biodegradation data in soil or water were not available. However, based on pure culture studies resulting in oxidation of cis- and trans-2-butene and subsequent accumulation of the metabolite, primary biodegradation may be an important environmental fate process under certain conditions in soil and water. If released into water, 2-butene 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 hours and 3 days, respectively. An estimated BCF of 8 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 (pH 5 to 9). Occupational exposure, especially workers in the petroleum industry, are likely exposed to 2-butene via inhalation and dermal contact with this compound at workplaces where 2-butene is produced or used. Monitoring and use data indicate that the general population may be exposed to 2-butene via inhalation of ambient air especially near combustion fuel exhaust sources, inhalation of tobacco smoke, and dermal contact with consumer products containing 2-butene, especially during the use of gasoline products. (SRC)

cis-2-Butene's production and use as a solvent, cross-linking agent, in the polymerization of gasoline, butadiene synthesis, and synthesis of C4 and C5 derivatives may result in its release to the environment through various waste streams. If released to air, a vapor pressure of 1600 mm Hg at 25 °C indicates cis-2-butene will exist solely as a gas in the atmosphere. Gas-phase cis-2-butene will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals, ozone molecules, and nitrate radicals; the half-life for the reaction with hydroxyl radicals in air is estimated to be 7 hours; the half-life for the reaction with ozone molecules is estimated to be 2 hours; the half-life for the nighttime reaction with nitrate radicals is estimated to be 0.5 hours. cis-2-Butene 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, cis-2-butene is expected to have high mobility based upon an estimated Koc of 100. Volatilization from moist soil surfaces is expected to be an important fate process based upon a Henry's Law constant of 0.231 atm-cu m/mole. cis-2-Butene may volatilize from dry soil surfaces based upon its vapor pressure. Biodegradation data in soil or water were not available. However, based on pure culture studies resulting in oxidation of cis-2-butene and subsequent accumulation of the metabolite, primary biodegradation may be an important environmental fate process under certain conditions in soil and water. If released into water, cis-2-butene 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 Henry's Law constant. Estimated volatilization half-lives for a model river and model lake are 2 hours and 3 days, respectively. An estimated BCF of 16 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 (pH 5 to 9). Occupational exposure to cis-2-butene may occur through inhalation and dermal contact with this compound at workplaces where cis-2-butene is produced or used. The general population may be exposed to cis-2-butene via inhalation of ambient air especially near combustion fuel exhaust sources, inhalation of tobacco smoke, and dermal contact with consumer products containing cis-2-butene, especially during the use of gasoline products. (SRC)

2-Butene is an anthropogenic compound and it is not known to exist in nature(1).

cis-2-Butene is an anthropogenic compound and is not known to occur naturally(1).

2-Butene's production and use in the production of gasolines, butadiene and other chemicals(1) may result in its release to the environment through various waste streams(SRC). 2-Butene is an isomeric mixture of trans-and cis-2-butene recovered from refining gases or produced by petroleum cracking(2). 2-Butene occurs in coal gas and has been detected in diesel exhaust(2). 2-Butene has been identified as a constituent of tobacco smoke(3).

cis-2-Butene's production and use as a solvent, cross-linking agent, in the polymerization of gasoline, in butadiene synthesis, and in the synthesis of C4 and C5 derivatives(1) may result in its release to the environment through various waste streams(SRC). cis-2-Butene occurs in coal gas(2). cis-2-Butene is found in gasoline at 0.09-0.35 vol%, in evaporate from gasoline fuel tank at 4.20 vol%, and evaporate from carburetor at 0.2-0.3 vol%(3). cis-2-Butene has been identified as a constituent of tobacco smoke(4).

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 40(SRC), determined from a log Kow of 1.85(2) and a regression-derived equation(3), indicates that 2-butene is expected to have very high mobility in soil(SRC). Volatilization of 2-butene from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 1.54X10-1 atm-cu m/mole(SRC), using a fragment constant estimation method(4). 2-Butene is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 1600 mm Hg at 25 °C(5). Biodegradation data in soil were not available(SRC, 2018). However, based on pure culture studies resulting in oxidation of cis- and trans-2-butene and subsequent accumulation of the metabolite(6), primary biodegradation may be an important environmental fate process under certain conditions in soil(SRC).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 40(SRC), determined from a log Kow of 1.85(2) and a regression-derived equation(3), indicates that 2-butene is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(4) based upon an estimated Henry's Law constant of 1.54X10-1 atm-cu m/mole(SRC), developed using a fragment constant estimation method(5). Using this Henry's Law constant and an estimation method(4), volatilization half-lives for a model river and model lake are 2 hours and 3 days, respectively(SRC). According to a classification scheme(6), an estimated BCF of 8(SRC), from its log Kow(2) and a regression-derived equation(3), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Biodegradation data in water were not available(SRC, 2018). However, based on pure culture studies resulting in oxidation of cis- and trans-2-butene and subsequent accumulation of the metabolite(7), primary biodegradation may be an important environmental fate process under certain conditions in water(SRC).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), 2-butene, which has a vapor pressure of 1600 mm Hg at 25 °C(2), is expected to exist solely as a gas in the ambient atmosphere. Gas-phase 2-butene 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 6.4 hours(SRC), calculated from its rate constant of 6.00X10-11 cu cm/molecule-sec at 25 °C(3). The rate constant for the vapor-phase reaction of 2-butene with ozone has been measured in the range of 5.98X10-17 to 4.32X10-16 cu cm/molecule-sec at 25 °C(4). This corresponds to an atmospheric half-life of about 0.64 to 4.6 hours at an atmospheric concentration of 7X10+11 ozone molecules per cu cm(4). The rate constant for the gas-phase nighttime reaction of 2-butene with nitrate radicals has been measured in the range of 1.89X10-13 to 2.11X10-13 cu cm/molecule-sec at 25 °C(5). This corresponds to an atmospheric half-life of about 0.5 hours at an atmospheric concentration of 2X10+9 nitrate radicals per cu cm(5). 2-Butene does not contain chromophores that absorb at wavelengths >290 nm(6) and, therefore, is not expected to be susceptible to direct photolysis by sunlight(SRC).

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 100(SRC), determined from a log Kow of 2.33(2) and a regression-derived equation(3), indicates that cis-2-butene is expected to have high mobility in soil(SRC). Volatilization of cis-2-butene from moist soil surfaces is expected to be an important fate process(SRC) given a Henry's Law constant of 0.231 atm-cu m/mole(4). cis-2-butene is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 1600 mm Hg at 25 °C(5). Biodegradation data in soil were not available(SRC, 2018). However, based on pure culture studies resulting in oxidation of cis-2-butene and subsequent accumulation of the metabolite(6), primary biodegradation may be an important environmental fate process under certain conditions in soil(SRC).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 100(SRC), determined from a log Kow of 2.33(2) and a regression-derived equation(3), indicates that cis-2-butene is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(4) based upon a Henry's Law constant of 0.231 atm-cu m/mole(5). Using this Henry's Law constant and an estimation method(4), volatilization half-lives for a model river and model lake are 2 hours and 3 days, respectively(SRC). According to a classification scheme(6), an estimated BCF of 16(SRC), from its log Kow(2) and a regression-derived equation(3), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Biodegradation data in water were not available(SRC, 2018). However, based on pure culture studies resulting in oxidation of cis-2-butene and subsequent accumulation of the metabolite(7), primary biodegradation may be an important environmental fate process under certain conditions in water(SRC).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), cis-2-butene, which has a vapor pressure of 1600 mm Hg at 25 °C(2), is expected to exist solely as a gas in the ambient atmosphere. Gas-phase cis-2-butene is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals, ozone molecules, and nitrate radicals(SRC). The half-life for the reaction with hydroxyl radicals is estimated to be 7 hours(SRC) calculated from its rate constant of 5.6X10-11 cu cm/molecule-sec at 25 °C(3). The half-life for the reaction with ozone molecules is estimated to be 2 hours(SRC) calculated from its rate constant of 1.3X10-16 cu cm/molecule-sec at 25 °C(4). The half-life for the nighttime reaction with nitrate radicals is estimated to be 0.5 hours(SRC) calculated from its rate constant of 1.89X10-13 cu cm/molecule-sec at 25 °C(5). cis-2-Butene does not contain chromophores that absorb at wavelengths >290 nm(6) and, therefore, is not expected to be susceptible to direct photolysis by sunlight(SRC).

PURE CULTURE: Pure cultures of methanotrophic bacteria isolated from soil and water were found to oxidize cis- and trans-2-butene to cis- and trans-2-butene-1-ol and which is then epoxidized to cis- and trans-2,3-epoxybutane(1-3). Epoxides were not further metabolized and accumulated extracellularly(1). These data suggest that biodegradation may be an important environmental fate process(SRC).

PURE CULTURE: Pure cultures of methanotrophic bacteria isolated from soil and water were found to oxidize cis-2-butene to cis-2-butene-1-ol and then epoxidized to cis-2,3-epoxybutane(1-3). The rate of cis-2-butene oxidation to cis-2,3-epoxybutane was 0.18 umol/10 min-mg of protein(3). Epoxides were not further metabolized and accumulated extracelluarly(1). These data suggest that biodegradation may be an important environmental fate process(SRC).

The rate constant for the vapor-phase reaction of 2-butene with photochemically-produced hydroxyl radicals has been estimated as 6.00X10-11 cu cm/molecule-sec at 25 °C(1). This corresponds to an atmospheric half-life of about 6.4 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(SRC). The rate constant for the vapor-phase reaction of 2-butene with ozone has been measured in the range of 5.98X10-17 to 4.32X10-16 cu cm/molecule-sec at 25 °C(2). This corresponds to an atmospheric half-life of about 0.64 to 4.6 hours at an atmospheric concentration of 7X10+11 ozone molecules per cu cm(2). The rate constant for the gas-phase nighttime reaction of 2-butene with nitrate radicals has been measured in the range of 1.89X10-13 to 2.11X10-13 cu cm/molecule-sec at 25 °C(3). This corresponds to an atmospheric half-life of about 0.5 hours at an atmospheric concentration of 2X10+9 nitrate radicals per cu cm(3). 2-Butene is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(4). 2-Butene does not contain chromophores that absorb at wavelengths >290 nm(4) and, therefore, is not expected to be susceptible to direct photolysis by sunlight(SRC).

The rate constant for the gas-phase reaction of cis-2-butene with photochemically-produced hydroxyl radicals has been measured as 5.6X10-11 cu cm/molecule-sec at 25 °C(1). This corresponds to an atmospheric half-life of about 7 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). The rate constant for the gas-phase reaction of cis-2-butene with ozone molecules has been measured as 1.3X10-16 cu cm/molecule-sec at 25 °C(2). This corresponds to an atmospheric half-life of about 2 hours at an atmospheric concentration of 7X10+11 ozone molecules per cu cm(2). The rate constant for the gas-phase nighttime reaction of cis-2-butene with nitrate radicals has been measured as 1.89X10-13 cu cm/molecule-sec at 25 °C(3). This corresponds to an atmospheric half-life of about 0.5 hours at an atmospheric concentration of 2X10+9 nitrate radicals per cu cm(3). cis-2-Butene is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(4). cis-2-Butene does not contain chromophores that absorb at wavelengths >290 nm(4) and, therefore, is not expected to be susceptible to direct photolysis by sunlight(SRC).

An estimated BCF of 8 was calculated in fish for 2-butene(SRC), using a log Kow of 1.85(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).

An estimated BCF of 16 was calculated in fish for cis-2-butene(SRC), using a log Kow of 2.33(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.

The Koc of 2-butene is estimated as 40(SRC), using a log Kow of 1.85(1) and a regression-derived equation(2). According to a classification scheme(3), this estimated Koc value suggests that 2-butene is expected to have very high mobility in soil.

The Koc of cis-2-butene is estimated as 100(SRC), using a log Kow of 2.33(1) and a regression-derived equation(2). According to a classification scheme(3), this estimated Koc value suggests that cis-2-butene is expected to have high mobility in soil.

The Henry's Law constant for 2-butene is estimated as 1.54X10-1 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that 2-butene is expected to volatilize rapidly 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 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 days(SRC). 2-Butene's Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC). 2-Butene is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 1600 mm Hg at 25 °C(3).

The Henry's Law constant for cis-2-butene is 0.231 atm-cu m/mole(1). This Henry's Law constant indicates that cis-2-butene is expected to volatilize rapidly 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 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 days(SRC). cis-2-Butene's Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC). cis-2-butene is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 1600 mm Hg at 25 °C(3).

2-Butene's production and use in the production of gasolines, butadiene and other chemicals may result in its release to the environment through various waste streams. If released to air, a vapor pressure of 1600 mm Hg at 25 °C indicates 2-butene will exist solely as a gas in the atmosphere. Gas-phase 2-butene 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 6.4 hours. Gas-phase 2-butene will be degraded in the atmosphere by reaction with ozone; the half-life for this reaction in air is estimated to be 0.64 to 6.4 hours. Gas-phase 2-butene will be degraded in the atmosphere by nighttime reaction with nitrate radicals; the half-life for this reaction in air is estimated to be 0.5 hours. 2-Butene 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-butene is expected to have very high mobility based upon an estimated Koc of 40. Volatilization from moist soil surfaces is expected to be an important fate process based upon an estimated Henry's Law constant of 1.54X10-1 atm-cu m/mole. 2-Butene may volatilize from dry soil surfaces based upon its vapor pressure. Biodegradation data in soil or water were not available. However, based on pure culture studies resulting in oxidation of cis- and trans-2-butene and subsequent accumulation of the metabolite, primary biodegradation may be an important environmental fate process under certain conditions in soil and water. If released into water, 2-butene 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 hours and 3 days, respectively. An estimated BCF of 8 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 (pH 5 to 9). Occupational exposure, especially workers in the petroleum industry, are likely exposed to 2-butene via inhalation and dermal contact with this compound at workplaces where 2-butene is produced or used. Monitoring and use data indicate that the general population may be exposed to 2-butene via inhalation of ambient air especially near combustion fuel exhaust sources, inhalation of tobacco smoke, and dermal contact with consumer products containing 2-butene, especially during the use of gasoline products. (SRC)

cis-2-Butene's production and use as a solvent, cross-linking agent, in the polymerization of gasoline, butadiene synthesis, and synthesis of C4 and C5 derivatives may result in its release to the environment through various waste streams. If released to air, a vapor pressure of 1600 mm Hg at 25 °C indicates cis-2-butene will exist solely as a gas in the atmosphere. Gas-phase cis-2-butene will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals, ozone molecules, and nitrate radicals; the half-life for the reaction with hydroxyl radicals in air is estimated to be 7 hours; the half-life for the reaction with ozone molecules is estimated to be 2 hours; the half-life for the nighttime reaction with nitrate radicals is estimated to be 0.5 hours. cis-2-Butene 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, cis-2-butene is expected to have high mobility based upon an estimated Koc of 100. Volatilization from moist soil surfaces is expected to be an important fate process based upon a Henry's Law constant of 0.231 atm-cu m/mole. cis-2-Butene may volatilize from dry soil surfaces based upon its vapor pressure. Biodegradation data in soil or water were not available. However, based on pure culture studies resulting in oxidation of cis-2-butene and subsequent accumulation of the metabolite, primary biodegradation may be an important environmental fate process under certain conditions in soil and water. If released into water, cis-2-butene 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 Henry's Law constant. Estimated volatilization half-lives for a model river and model lake are 2 hours and 3 days, respectively. An estimated BCF of 16 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 (pH 5 to 9). Occupational exposure to cis-2-butene may occur through inhalation and dermal contact with this compound at workplaces where cis-2-butene is produced or used. The general population may be exposed to cis-2-butene via inhalation of ambient air especially near combustion fuel exhaust sources, inhalation of tobacco smoke, and dermal contact with consumer products containing cis-2-butene, especially during the use of gasoline products. (SRC)

2-Butene is an anthropogenic compound and it is not known to exist in nature(1).

cis-2-Butene is an anthropogenic compound and is not known to occur naturally(1).

2-Butene's production and use in the production of gasolines, butadiene and other chemicals(1) may result in its release to the environment through various waste streams(SRC). 2-Butene is an isomeric mixture of trans-and cis-2-butene recovered from refining gases or produced by petroleum cracking(2). 2-Butene occurs in coal gas and has been detected in diesel exhaust(2). 2-Butene has been identified as a constituent of tobacco smoke(3).

cis-2-Butene's production and use as a solvent, cross-linking agent, in the polymerization of gasoline, in butadiene synthesis, and in the synthesis of C4 and C5 derivatives(1) may result in its release to the environment through various waste streams(SRC). cis-2-Butene occurs in coal gas(2). cis-2-Butene is found in gasoline at 0.09-0.35 vol%, in evaporate from gasoline fuel tank at 4.20 vol%, and evaporate from carburetor at 0.2-0.3 vol%(3). cis-2-Butene has been identified as a constituent of tobacco smoke(4).

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 40(SRC), determined from a log Kow of 1.85(2) and a regression-derived equation(3), indicates that 2-butene is expected to have very high mobility in soil(SRC). Volatilization of 2-butene from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 1.54X10-1 atm-cu m/mole(SRC), using a fragment constant estimation method(4). 2-Butene is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 1600 mm Hg at 25 °C(5). Biodegradation data in soil were not available(SRC, 2018). However, based on pure culture studies resulting in oxidation of cis- and trans-2-butene and subsequent accumulation of the metabolite(6), primary biodegradation may be an important environmental fate process under certain conditions in soil(SRC).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 40(SRC), determined from a log Kow of 1.85(2) and a regression-derived equation(3), indicates that 2-butene is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(4) based upon an estimated Henry's Law constant of 1.54X10-1 atm-cu m/mole(SRC), developed using a fragment constant estimation method(5). Using this Henry's Law constant and an estimation method(4), volatilization half-lives for a model river and model lake are 2 hours and 3 days, respectively(SRC). According to a classification scheme(6), an estimated BCF of 8(SRC), from its log Kow(2) and a regression-derived equation(3), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Biodegradation data in water were not available(SRC, 2018). However, based on pure culture studies resulting in oxidation of cis- and trans-2-butene and subsequent accumulation of the metabolite(7), primary biodegradation may be an important environmental fate process under certain conditions in water(SRC).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), 2-butene, which has a vapor pressure of 1600 mm Hg at 25 °C(2), is expected to exist solely as a gas in the ambient atmosphere. Gas-phase 2-butene 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 6.4 hours(SRC), calculated from its rate constant of 6.00X10-11 cu cm/molecule-sec at 25 °C(3). The rate constant for the vapor-phase reaction of 2-butene with ozone has been measured in the range of 5.98X10-17 to 4.32X10-16 cu cm/molecule-sec at 25 °C(4). This corresponds to an atmospheric half-life of about 0.64 to 4.6 hours at an atmospheric concentration of 7X10+11 ozone molecules per cu cm(4). The rate constant for the gas-phase nighttime reaction of 2-butene with nitrate radicals has been measured in the range of 1.89X10-13 to 2.11X10-13 cu cm/molecule-sec at 25 °C(5). This corresponds to an atmospheric half-life of about 0.5 hours at an atmospheric concentration of 2X10+9 nitrate radicals per cu cm(5). 2-Butene does not contain chromophores that absorb at wavelengths >290 nm(6) and, therefore, is not expected to be susceptible to direct photolysis by sunlight(SRC).

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 100(SRC), determined from a log Kow of 2.33(2) and a regression-derived equation(3), indicates that cis-2-butene is expected to have high mobility in soil(SRC). Volatilization of cis-2-butene from moist soil surfaces is expected to be an important fate process(SRC) given a Henry's Law constant of 0.231 atm-cu m/mole(4). cis-2-butene is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 1600 mm Hg at 25 °C(5). Biodegradation data in soil were not available(SRC, 2018). However, based on pure culture studies resulting in oxidation of cis-2-butene and subsequent accumulation of the metabolite(6), primary biodegradation may be an important environmental fate process under certain conditions in soil(SRC).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 100(SRC), determined from a log Kow of 2.33(2) and a regression-derived equation(3), indicates that cis-2-butene is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(4) based upon a Henry's Law constant of 0.231 atm-cu m/mole(5). Using this Henry's Law constant and an estimation method(4), volatilization half-lives for a model river and model lake are 2 hours and 3 days, respectively(SRC). According to a classification scheme(6), an estimated BCF of 16(SRC), from its log Kow(2) and a regression-derived equation(3), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Biodegradation data in water were not available(SRC, 2018). However, based on pure culture studies resulting in oxidation of cis-2-butene and subsequent accumulation of the metabolite(7), primary biodegradation may be an important environmental fate process under certain conditions in water(SRC).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), cis-2-butene, which has a vapor pressure of 1600 mm Hg at 25 °C(2), is expected to exist solely as a gas in the ambient atmosphere. Gas-phase cis-2-butene is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals, ozone molecules, and nitrate radicals(SRC). The half-life for the reaction with hydroxyl radicals is estimated to be 7 hours(SRC) calculated from its rate constant of 5.6X10-11 cu cm/molecule-sec at 25 °C(3). The half-life for the reaction with ozone molecules is estimated to be 2 hours(SRC) calculated from its rate constant of 1.3X10-16 cu cm/molecule-sec at 25 °C(4). The half-life for the nighttime reaction with nitrate radicals is estimated to be 0.5 hours(SRC) calculated from its rate constant of 1.89X10-13 cu cm/molecule-sec at 25 °C(5). cis-2-Butene does not contain chromophores that absorb at wavelengths >290 nm(6) and, therefore, is not expected to be susceptible to direct photolysis by sunlight(SRC).

PURE CULTURE: Pure cultures of methanotrophic bacteria isolated from soil and water were found to oxidize cis- and trans-2-butene to cis- and trans-2-butene-1-ol and which is then epoxidized to cis- and trans-2,3-epoxybutane(1-3). Epoxides were not further metabolized and accumulated extracellularly(1). These data suggest that biodegradation may be an important environmental fate process(SRC).

PURE CULTURE: Pure cultures of methanotrophic bacteria isolated from soil and water were found to oxidize cis-2-butene to cis-2-butene-1-ol and then epoxidized to cis-2,3-epoxybutane(1-3). The rate of cis-2-butene oxidation to cis-2,3-epoxybutane was 0.18 umol/10 min-mg of protein(3). Epoxides were not further metabolized and accumulated extracelluarly(1). These data suggest that biodegradation may be an important environmental fate process(SRC).

The rate constant for the vapor-phase reaction of 2-butene with photochemically-produced hydroxyl radicals has been estimated as 6.00X10-11 cu cm/molecule-sec at 25 °C(1). This corresponds to an atmospheric half-life of about 6.4 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(SRC). The rate constant for the vapor-phase reaction of 2-butene with ozone has been measured in the range of 5.98X10-17 to 4.32X10-16 cu cm/molecule-sec at 25 °C(2). This corresponds to an atmospheric half-life of about 0.64 to 4.6 hours at an atmospheric concentration of 7X10+11 ozone molecules per cu cm(2). The rate constant for the gas-phase nighttime reaction of 2-butene with nitrate radicals has been measured in the range of 1.89X10-13 to 2.11X10-13 cu cm/molecule-sec at 25 °C(3). This corresponds to an atmospheric half-life of about 0.5 hours at an atmospheric concentration of 2X10+9 nitrate radicals per cu cm(3). 2-Butene is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(4). 2-Butene does not contain chromophores that absorb at wavelengths >290 nm(4) and, therefore, is not expected to be susceptible to direct photolysis by sunlight(SRC).

The rate constant for the gas-phase reaction of cis-2-butene with photochemically-produced hydroxyl radicals has been measured as 5.6X10-11 cu cm/molecule-sec at 25 °C(1). This corresponds to an atmospheric half-life of about 7 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). The rate constant for the gas-phase reaction of cis-2-butene with ozone molecules has been measured as 1.3X10-16 cu cm/molecule-sec at 25 °C(2). This corresponds to an atmospheric half-life of about 2 hours at an atmospheric concentration of 7X10+11 ozone molecules per cu cm(2). The rate constant for the gas-phase nighttime reaction of cis-2-butene with nitrate radicals has been measured as 1.89X10-13 cu cm/molecule-sec at 25 °C(3). This corresponds to an atmospheric half-life of about 0.5 hours at an atmospheric concentration of 2X10+9 nitrate radicals per cu cm(3). cis-2-Butene is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(4). cis-2-Butene does not contain chromophores that absorb at wavelengths >290 nm(4) and, therefore, is not expected to be susceptible to direct photolysis by sunlight(SRC).

An estimated BCF of 8 was calculated in fish for 2-butene(SRC), using a log Kow of 1.85(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).

An estimated BCF of 16 was calculated in fish for cis-2-butene(SRC), using a log Kow of 2.33(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.

The Koc of 2-butene is estimated as 40(SRC), using a log Kow of 1.85(1) and a regression-derived equation(2). According to a classification scheme(3), this estimated Koc value suggests that 2-butene is expected to have very high mobility in soil.

The Koc of cis-2-butene is estimated as 100(SRC), using a log Kow of 2.33(1) and a regression-derived equation(2). According to a classification scheme(3), this estimated Koc value suggests that cis-2-butene is expected to have high mobility in soil.

The Henry's Law constant for 2-butene is estimated as 1.54X10-1 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that 2-butene is expected to volatilize rapidly 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 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 days(SRC). 2-Butene's Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC). 2-Butene is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 1600 mm Hg at 25 °C(3).

The Henry's Law constant for cis-2-butene is 0.231 atm-cu m/mole(1). This Henry's Law constant indicates that cis-2-butene is expected to volatilize rapidly 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 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 days(SRC). cis-2-Butene's Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC). cis-2-butene is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 1600 mm Hg at 25 °C(3).

2-Butene was listed as a compound present in both gasoline and the exhaust from motor vehicles(1). The estimated annual emissions of 2-butene from gasoline powered vehicles in the UK in 1983 was 5.58 kilo tons(1). The average concentration of 2-butene in the exhaust of 67 Australian gasoline vehicles was 1.1% w/w of the total non methane hydrocarbons(2). 2-Butene was identified as a stack emission from a waste incinerator(3).

2-Butene was identified, not quantified, in automobile emissions in Canada(1) and 4-stroke lawn mowers(2). The emission rate of 2-butene from typical automobiles was reported as 27-37 mg per liter of gasoline(3). The emission rate of 2-butene from ferries with diesel engines was reported as 0.1-0.3 mg/kWh(4). Car exhaust in London, England contained 2-butene at an avg concentration of 648 and 822 ppb(5). 2-Butene was detected at concentrations of 1.12-5.7 ug/cu m in the effluent of a Swedish cat-cracking refinery(6).

cis-2-Butene was identified, not quantified, in automobile emissions in Canada(1) and 4-stroke lawn mowers(2). The emission rate of cis-2-butene from typical automobiles was reported as 27 mg per liter of gasoline(3). The emission rate of cis-2-butene from ferries with diesel engines was reported as 0.2 and 0.1 mg/kWh(4). Car exhaust in London, England contained cis-2-butene at an avg concentration of 648 ppb(5). cis-2-Butene was identified, not quantified, in exhaust from a moped and lawnmower(6). cis-2-Butene was detected at concentrations of 1.12-5.7 ug/cu m in the effluent of a Swedish cat-cracking refinery(7).

URBAN/SUBURBAN: 2-Butene was detected, but not quantified, in the air of Elizabeth and Pine Barrens, NJ, 1979(1). The concentration of 2-butene taken from the top of an 82 story building at noon in New York City, 1977, ranged from 5.0-6.7 ug/cu m(2). The average concentration of 2-butene and isobutene, measured in 780 samples from Houston, TX, Summer 1977, was 4 ppb(3). The concentration of 2-butene in downtown Houston obtained during two separate day-long sampling expeditions in July of 1973 ranged from not detected to 0.012 ppm and from not detected to 0.02 ppm in three sampling expeditions in Pasadena, TX(4). The concentration of 2-butene in two rooftop samples taken in Riverside, CA, 1965-66 was 10.5 and 2.0 ppb, respectively(5). 2-Butene was qualitatively identified in roadway air samples(6). 2-Butene, as a mixture with 1,3-butadiene, was determined in the air of Jones State Forest, TX, in 1978(7).

URBAN/SUBURBAN: The estimated annual mean concentration of 2-butene in London, England is 3 ug/cu m(1). The observed background level of 2-butene in Sidney, Australia, was 5.1 ug/cu m(1). The mean concentration of 2-butene in urban, rural, and polluted rural locations in NW England, 1983, was 27.6, <2.1 and 5.6 ppb, respectively(2). The average concentration of 2-butene in Sidney, Australia, 1979-1980, was 2.1 ppb(3).

URBAN/SUBURBAN: 2-Butene was reported in urban air in Porto Alegre, Brazil in 1996 at a mean concentration of 2.3 and 3.2 mg/cu m(1). 2-Butene was detected in 1993 at an avg concentration of 0.75 ug/cu m (not detected-3.0 ug/cu m) in Los Angeles, CA(2). 2-Butene was detected in 53% of the air samples obtained in Atlanta, GA at concentrations of 0.1-0.15 ppb(3). Mean concentrations of 3-13.9 ppb 2-butene were reported for various sites around Vienna, Austria(4).

RURAL/REMOTE: 2-Butene was detected in the atmosphere of the Borden Forest, Canada in 1993 at concentrations of 0.02-0.1 ppb during daytime hours and 0.01-0.09 ppb during nighttime hours(1). 2-Butene was detected in Egbert, Canada at a concentration of 0.166-0.038 ppb(2). 2-Butene (trans) was detected in the Kejimkujik National Park, Nova Scotia (not detected-0.05 ppb), Lac la Flamme, Canada (not detected-0.03 ppb), Egbert, Canada (not detected-0.02 ppb) and Saturna Island, Canada (not detected-0.03 ppb)(3). 2-Butene was qualitatively detected in the Eggegebirge Forest, West Germany, 1988(4).

SOURCE DOMINATED: 2-Butene was reported at average concentrations of 0.334-0.408 ppb along roadsides and at 0.149-0.159 ppb at airports in Atlanta, GA(1). The concentration of 2-butene at an unspecified street in London, England was reported as 7.1-9 ppb(2). 2-Butene was reported in the Caldecott Tunnel, CA at mean concentration of 6.6-11.2 mg/l in August of 1994 when low oxygenated fuels (0.3%) were being employed in the San Francisco area(3). 2-Butene was reported in the Caldecott Tunnel, CA at a mean concentration of 13.6-15 mg/l in October of 1994 when high oxygenated fuels (2%) were being employed in the San Francisco area(3). At 16 locations during the summer, monsoon, and winter season 2004 in the Thane Belapur Industrial Area in Mumbai, 2-butene was identified but not quantified, as a volatile component in source air samples collected in the vicinity of processing units and storage plants of industrial units in the sampling area(4).

URBAN/SUBURBAN: cis-2-Butene was reported in urban air in Porto Alegre, Brazil in 1996 at a mean concentration of 2.3 mg/cu m(1). cis-2-Butene was reported in 1993 at an average concentration of 0.75 ug/cu m (0.0-3.0 ug/cu m) in Los Angeles, CA(2). cis-2-Butene was detected in 51% of the air samples obtained in Atlanta, GA at concentrations of 0.1-0.15 ppb(3). Mean concentrations of 3-4 ppb cis-2-butene were reported for various sites around Vienna, Austria(4). cis-2-Butene was detected at estimated concentrations ranging from 0.0-1.6 ppbv (average = 0.4 ppbv) in air samples colleted over a 1-hour period in Taipei, Twain on January 29, 1997(5).

RURAL/REMOTE: cis-2-Butene was detected in the atmosphere of the Borden Forest, Canada in 1993 at concentrations of 0.02-0.04 ppb during daytime hours and 0.01-0.03 ppb during nighttime hours(1). cis-2-Butene was detected in Egbert, Canada at a concentration of 0.166 ppb(2).

SOURCE DOMINATED: cis-2-Butene was reported at an average concentration of 0.334 ppb along roadsides and at 0.159 ppb at airports in Atlanta, GA(1). The concentration of cis-2-butene at an unspecified street in London, England was reported as 7.1 ppb(2). cis-2-Butene was reported in the Caldecott Tunnel, CA at a mean concentration of 6.6 mg/l in August of 1994 when low oxygenated fuels (0.3%) were being employed in the San Francisco area(3). cis-2-Butene was reported in the Caldecott Tunnel, CA at a mean concentration of 13.6 mg/l in October of 1994 when high oxygenated fuels (2%) were being employed in the San Francisco area(3). cis-2-Butene was identified, not quantified, in the Tingstad Tunnel, Sweden(4).

2-Butene was detected at an average concentration of 126.3 ug/m cu in samples collected on June 9, 2004 at a gasoline service station in Rio de Janeiro(1). In samples from various dairy silages and feed samples collected from a commercial dairy in California, 2-butene was detected in the volatile emissions at average concentrations of 23.37, 2.82, 4.38, and 1.59 nL/L in corn silage, alfalfa silage, high moisture ground corn, and total mixed rations, respectively(2).

cis-2-Butene was detected in the gas phase of smoke emissions from a residential chimney upon combustion of pine firewood at 35.4 mg/kg of wood burned(1). cis-2-Butene was detected in 13 of 16 various fuel/stove combinations using coal, wood, residues and gas as fuel sources with emission rates ranging between 0.081-3.44 mg/kg dry fuel(2).

According to the 2016 TSCA Inventory Update Reporting data, 1 reporting facility estimates the number of persons reasonably likely to be exposed during the manufacturing, processing, or use of 2-butene in the United States may be as low as 25 workers and as high as 49 workers per plant; the data may be greatly underestimated due to confidential business information (CBI) or unknown values(1).

NIOSH (NOES Survey 1981-1983) has statistically estimated that 545 workers (0 of these are female) were potentially exposed to 2-butene in the US(1). Occupational exposure, especially workers in the petroleum industry, are likely exposed to 2-butene via inhalation and dermal contact with this compound at workplaces where 2-butene is produced or used(SRC). Workers were exposed to 2-butene during the loading of gasoline at bulk or marine terminals(2). Monitoring and use data indicate that the general population may be exposed to 2-butene via inhalation of ambient air especially near combustion fuel exhaust sources, inhalation of tobacco smoke, and dermal contact with consumer products containing 2-butene, especially during the use of gasoline products(SRC).

According to the 2016 TSCA Inventory Update Reporting data, 5 reporting facilities estimate the number of persons reasonably likely to be exposed during the manufacturing, processing, or use of cis-2-butene in the United States may be as low as 100 workers and as high as 499 workers per plant; the data may be greatly underestimated due to confidential business information (CBI) or unknown values(1).

Occupational exposure to cis-2-butene may occur through inhalation and dermal contact with this compound at workplaces where cis-2-butene is produced or used. The general population may be exposed to cis-2-butene via inhalation of ambient air especially near combustion fuel exhaust sources, inhalation of tobacco smoke, and dermal contact with consumer products containing cis-2-butene, especially during the use of gasoline products. (SRC)

Intake: 11.5 mg/m cu: EHE max (maximum estimated human exposure) = 5 ppm or 11.5 mg/m cu equivalent to the peak concentration at working place(1). <0.23 mg/m cu TWA (time-weighted average) at working place or EHE mean <0.1ppm, (calculated)(1).

SRP: 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 air, soil or water; effects on animal, aquatic and plant life; and conformance with environmental and public health regulations. If it is possible or reasonable use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination.

Product: Burn in a chemical incinerator equipped with an afterburner and scrubber but exert extra care in igniting as this material is highly flammable. Offer surplus and non-recyclable solutions to a licensed disposal company. Contact a licensed professional waste disposal service to dispose of this material. Contaminated packaging: Dispose of as unused product.

/GUIDE 115 GASES - FLAMMABLE (Including Refrigerated Liquids)/ Fire or Explosion: EXTREMELY FLAMMABLE. Will be easily ignited by heat, sparks or flames. Will form explosive mixtures with air. Vapors from liquefied gas are initially heavier than air and spread along ground. CAUTION: Hydrogen (UN1049), Deuterium (UN1957), Hydrogen, refrigerated liquid (UN1966) and Methane (UN1971) are lighter than air and will rise. Hydrogen and Deuterium fires are difficult to detect since they burn with an invisible flame. Use an alternate method of detection (thermal camera, broom handle, etc.) Vapors may travel to source of ignition and flash back. Cylinders exposed to fire may vent and release flammable gas through pressure relief devices. Containers may explode when heated. Ruptured cylinders may rocket. /Butylene/

/GUIDE 115 GASES - FLAMMABLE (Including Refrigerated Liquids)/ Health: Vapors may cause dizziness or asphyxiation without warning. Some may be irritating if inhaled at high concentrations. Contact with gas or liquefied gas may cause burns, severe injury and/or frostbite. Fire may produce irritating and/or toxic gases. /Butylene/

/GUIDE 115 GASES - FLAMMABLE (Including Refrigerated Liquids)/ 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 100 meters (330 feet) in all directions. Keep unauthorized personnel away. Stay upwind, uphill and/or upstream. Many gases are heavier than air and will spread along ground and collect in low or confined areas (sewers, basements, tanks). /Butylene/

/GUIDE 115 GASES - FLAMMABLE (Including Refrigerated Liquids)/ Protective Clothing: Wear positive pressure self-contained breathing apparatus (SCBA). Structural firefighters' protective clothing will only provide limited protection. Always wear thermal protective clothing when handling refrigerated/cryogenic liquids. /Butylene/

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

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

UN 1012; Butylene

IMO 2.1; Butylene

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 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. Butylene is included on the dangerous goods list. /Butylene/

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. Butylene is included on the dangerous goods list. /Butylene/

Flammable Gas

H220; H280

UN Hazard Class: 2.1