But-2-ene

Hydroxyl radical reaction rate constant = 6.00X10-11 cu cm/mole-sec at 25 °C (isomer average)

Ozone reaction rate constant = 2.65X10-16 cu cm/mole-sec at 25 °C (est isomer average)

Danger

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

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.

Danger

H220: Extremely flammable gas [Danger Flammable gases]

Chemical: 2-Butene

Status: Active Update: 10-07-2020 https://echa.europa.eu/registration-dossier/-/registered-dossier/13346

2-Butene: HSNO Approval: HSR005566 Approved with controls

The New Jersey Worker and Community Right to Know Act requires public and private employers to provide information about hazardous substances at their workplaces. (N.J.S.A. 34:5A-1 et. seq.)

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.

/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.

Flam. Gas 1 (100%)

Flammable gases (including chemically unstable gases) - Category 1

Flammable agents - 4th degree

2-Butene

1

10000

Flammable chemical that can be released at a facility.

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.

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.

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/

750 [ppm]

2200 [ppm]

13000 [ppm]

2-Butene has been detected in exhaled air. In the majority of subjects, concentrations of the cis- form were greater than those for the trans- isomer(1). Of 18 personal air samples from attendants at a high volume gasoline service station in PA, 1983, 2-butene was detected but not quantified in 17 samples and measured in one sample at a concentration of 0.1 ppm(2). Workers in the petroleum field are likely to be exposed to 2-butene by inhalation of gasoline fumes during the production, transport or dispensing of motor fuels; personal air samples taken for workers in the petroleum industry indicated that 14 of 56 outside operators, 48 of 49 transport drivers and 48 of 49 service attendants were exposed to 2-butene(3).

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).

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.

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).

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).

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.

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).

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).

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).

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).

2-Butene

1

10000

Flammable chemical that can be released at a facility.

(1984) 3.56X10+11 g /1-Butene and 2-Butene mixed/

Non-confidential 2016 Chemical Data Reporting (CDR) information on the production and use of chemicals manufactured or imported into the United States. Chemical: 2-Butene:

There are two important sources for the commercial production of butylenes: catalytic or thermal cracking, and steam cracking. In these two processes, butylenes are always produced as by-products. /Butylenes/

1-Butene and isobutylene cannot be economically separated into pure components by conventional distillation because they are close boiling isomers. 2-Butene can be separated from the other two isomers by simple distillation. There are four types of separation methods available: (1) selective removal of isobutylene by polymerization and separation of 1-butene; (2) use of addition reactions with alcohol, acids, or water to selectively produce pure isobutylene and 1-butene; (3) selective extraction of isobutylene with a liquid solvent, usually an acid; and (4) physical separation of isobutylene from 1-butene by absorbents.

Disproportionation or the metathesis reaction offers an opportunity to convert surplus olefins to other desirable olefins. Phillips Petroleum and Institut Francais du Petrole have pioneered this technology for the dimerization of light olefins. The original metathesis reaction of Phillips Petroleum was intended to convert propylene to 2-butene and ethylene. The reverse reaction that converts 2-butene in the presence of excess ethylene to propylene has also been demonstrated. In this process, ethylene is first dimerized to 2-butene followed by metathesis to yield propylene. Since this is a two-stage process, 2-butene can be produced from the first stage, if needed. In the dimerization step, about 95% purity of 2-butene is achieved at 90% ethylene conversion.

... /A/ process has emerged that consists of catalytically hydroisomerizing 1-butene to 2-butenes. In this process, trace quantities of butadienes are also hydrogenated to yield feedstocks rich in isobutylene which can then be easily separated from 2-butenes by simple distillation. /2-Butenes/

For more Methods of Manufacturing (Complete) data for 2-Butene (6 total), please visit the HSDB record page.

2-Butene: ACTIVE

Butylenes are C4H8 mono-olefin isomers: 1-butene, cis-2-butene, trans-2-butene, and isobutylene (2-methylpropene). These isomers are usually coproduced as a mixture and are commonly referred to as the C4 fraction. These C4 fractions are usually obtained as by-products from petroleum refinery and petrochemical complexes that crack petroleum fractions and natural gas liquids. Since the C4 fractions almost always contain butanes, it is also known as the B-B stream. The linear isomers are referred to as butenes.

Butenes are unsaturated olefinic hydrocarbons, C4H8, Mr 56.1080, existing in four isomers: 1) 1-butene; 2) cis-2-butene; 3) trans-2-butene; and 4) 2-methylpropene (isobutene). In everyday use, the IUPAC nomenclature is less common than the use of older designations. Especially the branched-chain isomer 4 is commonly referred to as "isobutene" or "isobutylene" instead of the IUPAC name "2-methylpropene". The three linear chain isomers 1, 2, and 3 are usually referred to as "n-butenes" and often occur as mixtures during chemical processing. The old name "butylenes" is still in use for butenes.

2-Butene, C4H8, can occur in trans or cis conformation; the former is the more stable form.