Isobutan

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

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

Fresh air, rest. 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.

· CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper not available or no answer, refer to appropriate telephone number listed on the inside back cover.

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

· CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper not available or no answer, refer to appropriate telephone number listed on the inside back cover.

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

Excerpt from NIOSH Pocket Guide for Isobutane:

General First Aid:

General First Aid:

(General first aid procedures)

Vapors are heavier than air and will collect in low areas. Vapors may travel long distances to ignition sources and flashback. Vapors in confined areas may explode when exposed to fire. Containers may explode in fire. Storage containers and parts of containers may rocket great distances, in many directions.

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

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

1000.0 [ppm] (for Butane, isomers)[German Research Foundation (DFG)]

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.

Use water spray to cool unopened containers.

To fight fire, stop flow of gas.

For more Fire Fighting Procedures (Complete) data for Isobutane (6 total), please visit the HSDB record page.

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

Store separately from all other flammable materials. Prior to working with this chemical, you should be trained on its proper handling and storage. Before entering confined space where isobutane may be present, check to make sure that an explosive concentration odes not exist. Isobutane cylinders should be stored in a cool, well-ventilated dry area of noncombustible construction. Protect containers against physical damage. Store away from sources of heat or ignition and from oxygen, chlorine, and other oxidizers. Sources of ignition, such as smoking and open flames, are prohibited where isobutane is handled, used, or stored. Ground and bond all lines and equipment used with isobutane. Wherever isobutane is used, handled, manufactured, or stored, use explosion-proof electrical equipment and fittings. Procedures for the handling, use, and storage of cylinders should be in compliance with OSHA 1910.101 and 1910.169, as with the recommendations of the Compressed Gas Association.

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.

Restrict persons not wearing protective equipment from area of leak until cleanup is complete. Remove all ignition sources. Establish forced ventilation to keep levels below explosive limit. Stop flow of gas. If source of leak is a cylinder and the leak cannot be stopped in place, remove the leaking cylinder to a safe place in the open air, and repair leak or allow cylinder to empty. Keep isobutane out of a confined space, such as a sewer, because of the possibility of an explosion, unless the sewer is designed to prevent the buildup of explosive concentrations. Collect powdered material in the most convenient and safe manner and deposit in sealed containers. Ventilate area after cleanup is complete. It may be necessary to contain and dispose of this chemical as a hazardous waste. If material or contaminated runoff enters waterways, notify downstream users of potentially contaminated waters.

The efficiency of any soil venting operation will depend significantly on three factors: vapor flowrate, vapor flow path relative to the contaminant distribution, and composition of the contaminant. Simple mathematical models were developed to be used as screening tools to help determine if soil venting will be a viable remediation option at any given spill site. The models relate the applied vacuum, soil permeability, and spill composition to the vapor flowrates, velocities, mass removal rates, and residual composition changes with time. In this report the screening models and some sample calculations are presented . The results illustrate the advantages and limitations of venting as a remediation tool, under both ideal and nonideal conditions.

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.

SRP: Wastewater from contaminant suppression, cleaning of protective clothing/equipment, or contaminated sites should be contained and evaluated for subject chemical or decomposition product concentrations. Concentrations shall be lower than applicable environmental discharge or disposal criteria. Alternatively, pretreatment and/or discharge to a permitted wastewater treatment facility is acceptable only after review by the governing authority and assurance that "pass through" violations will not occur. Due consideration shall be given to remediation worker exposure (inhalation, dermal and ingestion) as well as fate during treatment, transfer and disposal. If it is not practicable to manage the chemical in this fashion, it must be evaluated in accordance with EPA 40 CFR Part 261, specifically Subpart B, in order to determine the appropriate local, state and federal requirements for disposal.

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.

Dissolve of mix the material with a combustible solvent and burn in a chemical incinerator equipped with an afterburner and scrubber. All federal, state, and local environmental regulations must be observed.

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 250(SRC), determined from a log Kow of 2.76(2) and a regression-derived equation(3), indicates that isobutane is expected to have moderate mobility in soil(SRC). Volatilization of isobutane from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 1.19 atm-cu m/mole(SRC), derived from its vapor pressure, 2610 mm Hg(4), and water solubility, 48.8 mg/L(5). Isobutane is expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(4). Isobutane reached 49% mineralization after 20 days using an activated sludge inoculum(6) suggesting that 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 250(SRC), determined from a log Kow of 2.76(2) and a regression-derived equation(3), indicates that isobutane is 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 1.19 atm-cu m/mole(SRC), derived from its vapor pressure, 2610 mm Hg(5), and water solubility, 48.8 mg/L(6). 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(7), an estimated BCF of 30(SRC), from its log Kow(2) and a regression-derived equation(3), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Microcosm experiments designed to simulate natural estuaries reported half-lives for isobutane ranging from 16-26 days(8) suggesting that biodegradation may be an important environmental fate process under certain conditions in water(SRC).

AQUATIC FATE: Experiments performed with gaseous C2-C4 alkanes in a microcosm designed to replicate Narragansett Bay, RI in September (20 °C) and November (10 °C) have shown that the removal rate constant of isobutane is 0.061/day (standard deviation 0.005/day) at 20 °C and 0.030/day (standard deviation 0.006/day) at 10 °C(1). The respective half-lives are 11 days and 23 days(SRC). The results indicate that gas exchange is the dominant removal mechanism for isobutane gases from the water column following a hypothetical input. Scaling up the predicted gas exchange rate constants (0.26/day and 0.017/day at 20 and 10 °C, respectively) so they are consistent with natural estuaries, the volatilization half-lives for isobutane from the water columns in natural estuaries(1) are estimated to be 4.4 and 6.8 days at 20 and 10 °C, respectively(SRC). Isobutane also biodegrades in the microcosm at a rate that is slower than for n-butane and falls between propane and ethane in susceptibility. Biodegradation of isobutane initially occurs with a half-lives of 16-26 days at 20 °C and 33-139 days at 10 °C, significantly slower than the loss predicted by gas exchange from typical natural estuaries. However, after a lag of 2-4 weeks, the biodegradation rate increases markedly so that in the case of chronic inputs, biodegradation can become the dominant removal mechanism(1).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), isobutane, which has a vapor pressure of 2610 mm Hg at 25 °C(2), is expected to exist solely as a gas in the ambient atmosphere. Gas-phase isobutane 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 6.8 days(SRC), calculated from its rate constant of 2.43X10-12 cu cm/molecule-sec at 25 °C(3). Gas-phase isobutane is degraded in the atmosphere by reaction with nitrate radicals(SRC); half-life for this reaction in air is estimated to be 165 days(4). Isobutane does not contain chromophores that absorb at wavelengths >290 nm(5) and, therefore, is not expected to be susceptible to direct photolysis by sunlight(SRC).

The substance can be absorbed into the body by inhalation.

inhalation, skin and/or eye contact (liquid)

Inhalation (L1283)

Safe in the present practices of use and concentration. Ingredient, concentration, and use information are available in documents discoverable at https://cir-reports.cir-safety.org

IDENTIFICATION AND USE: Isobutane is a colorless gas. It is used in organic synthesis, as a refrigerant, in motor fuels, and as aerosol propellant, as well as in synthetic rubber, and in instrument calibration fluid. HUMAN STUDIES: Isobutane is a simple asphyxiant. Acute exposure may cause tachypnea and tachycardia. In severe cases, hypotension, apnea, and cardiac arrest develop. Direct contact with the liquid produces chemical burns. Toxicologically, the vapor exerts no effect on skin and eyes. A case of ventricular fibrillation due to isobutane toxicity after unintentional inhalation of air freshener has been reported. The intentional inhalation of a volatile substance ("sniffing") causing euphoria and hallucinations is a form of substance abuse in children and adolescents with a high morbidity and mortality. Sudden death can be caused by cardiac arrhythmia, asphyxia or trauma. Fatal cases of isobutane sniffing of cigarette lighter refill containing isobutane has been reported. ANIMAL STUDIES: Studies in rabbits exposed through the eyes to undiluted hairspray containing 22% isobutane showed that irritation of the eye was immediately evident with transient iritis and mild conjunctivitis. Acute exposure in dogs to 55 mg/L isobutane was fatal, and 45 mg/L caused anesthesia. Two-hour exposures of mice to 41 mg/L isobutane caused death in 60% of the exposed animals, whereas exposure to 52 mg/L was lethal to 100% of the animals within an average of 28 min. Isobutane is a CNS depressant in the mouse at 15% in 60 min, and at 23% in 26 min. Isobutane caused apnea and finally cardiac arrest in anesthetized rats. Isobutane tested negative in the Ames Salmonella mutagenicity assay.

Butane is a simple asphyxiant and causes toxicity by displacing oxygen. It also affects the central nervous system by enhancing glycine receptors and inhibiting nicotinic acetylcholine and N-methyl-d-aspartate (NMDA) receptors, resulting in anesthetic effects. (L1284, A352)

Shortness of breath. Suffocation.

ON CONTACT WITH LIQUID: FROSTBITE.

drowsiness, narcosis, asphyxia; liquid: frostbite

Inhalation of butane can cause euphoria, hallucinations, confusion, blurred vision, slurred speech, nausea, vomiting, coughing, sneezing, increased salivation, drowsiness, narcosis, asphyxia, cardiac arrhythmia, and frostbite. (L1283, L1284)

In a comprehensive survey of wastewater from 4000 industrial and publicly owned treatment works (POTWs) sponsored by the Effluent Guidelines Division of the USEPA, isobutane was identified in discharges of the following industrial category (positive occurrences, median concentration in ppb): petroleum refining (1; 102.6), plastics and synthetics (1; 109.7), oil and gas extraction (3; 16.2)(1). The highest effluent concentration was 109.7 ppb in the plastics and synthetics industry(1).

Vehicle exhaust contained 720 ppb isobutane(2). In a 1988 study in the U.K., the 6-car average concentration of isobutane in exhaust gas was 8175 ppb(1).

Isobutane is found in gasoline and commercial natural gas(3) and may be released to the environment in evaporative losses, wastewater, and spills(SRC) as well as in combustion exhaust(3). Composition profiles for isobutane in auto emissions acquired using Federal Test Procedure tests include: USEPA 46 in-use vehicles for 1975-1982 model years, 0.92 wt%; Auto/Oil Program older (1983-1985) vehicle fleet, 0.21 wt%(3). Emissions of 25 vehicles (mostly 1986 model year) were tested under different driving conditions(1). The average emission were (type of driving (avg speed), emissions in mg/km): cold start (18.51 km/hr), 75.01; warm start (18.53 km/hr), 95.68; urban (21.38 km/hr), 65.66; suburban (41.73 km/hr), 29.64; rural (54.53 km/hr), 17.44; motorway (90.72 km/hr), 8.81; motorway (111.36 km/hr), 8.57(1,2). For suburban driving, 4 low-emission vehicles had isobutane emissions ranging from 0.8-18 mg/km at 40 km/hr(2). The emission of isobutane from a car dropped from 53 mg/km at 20 km/hr to 9 mg/hr between 90 and 110 km/hr(1). In emission tests using single component fuels, isobutane occurred in engine emissions when n-heptane, 1-hexene, and cyclohexane was burned, but not with toluene, isooctane or methyl tert-butyl ether (MTBE)(4).

Isobutane emission rates for the California South Coast Air Basin is 12.1 metric tons/day(6). A study of VOC emission in California South Coast Air Basin found that the sources of isobutane were (source, percent): gasoline exhaust, 6%; whole (liquid) gasoline, 3%; gasoline vapors, 36%; waste and natural gas, 21%; other, 34%(5). No isobutane emissions were attributed to coatings and adhesives(5). Isobutane gasoline exhaust emissions in the U.K have been estimated to be 5.29 and 14.5 kilotonnes by two investigators, constituting respectively 2% and 4% of exhaust emissions(1,3). Isobutane is found in underwater hydrocarbon vent plumes from offshore production; the concn in one plume was 560 umol/L(7). Isobutane constituted 0.004% of municipal sanitary landfill gas at Palos Verdes, CA(2). The landfill was in the anaerobic phase. Isobutane was found in emissions from the combustion of waste PVC plastics under conditions of incomplete combustion but not under conditions of complete combustion(4). Isobutane is used in consumer products such as insect spray, window and glass cleaner, personal care and pet products, arts and craft products, auto and home maintenance products and rug and upholstery cleaners(8,9) and may be released when these products are manufactured or used(SRC).

The Koc of isobutane is estimated as 250(SRC), using a log Kow of 2.76(1) and a regression-derived equation(2). According to a classification scheme(3), this estimated Koc value suggests that isobutane is expected to have moderate mobility in soil.

URBAN/SUBURBAN: The concentration of isobutane in air is largely a result of vehicle emissions and will be particularly sensitive to factors such as the sampling duration, type of location, wind direction, and time of day(2). This is exemplified by the concentration of isobutane in air at Riverside, CA (n=6, afternoon with a heavy haze), 5.2-10.4 ppb, compared with 0.2 ppb on a clear morning(3). Ambient air concentrations for isobutane in the National Ambient Volatile Organic Compounds data base (n = 887): mean 5.706 ppb, median 3.290 ppb, 25th percentile 1.728 ppb, 75th percentile 6.213 ppb(1). The median concentration by type of site were (type, number of data points, concentration): remote, 6, 0.158 ppb; rural, 36, 0.340 ppb; suburban, 223, 3.817 ppb; urban, 546, 3.275 ppb; source dominated, 56, 4.204 ppb(1). 4-Hour simultaneous air sampling on 15 days over a 3 month period in the summer of 1987 of an industrial, urban and suburban site in Chicago resulted in mean levels of 4.42, 2.16, and 2.12 ug/cu m, respectively(4). The concentration of isobutane in Japan along the direction of air mass movement was 4.4 ppb in Yokahama, 1.3 ppb in Takasaki, and 1.5 ppb in Kuruzawa(5). The decrease in concentration was attributed to photooxidation.

URBAN/SUBURBAN: Concentrations of isobutane resulting from urban (n = 34, interstate (n = 35), and rural (n = 7) driving was assessed in Raleigh, NC in the summer of 1988 using a 1983 and a 1987 model cars. The concentration was measured at: (a) the driver's breathing zone, (b) a location mid-route 100-300 ft from the roadway, (c) the car roof, (d) the breathing zone of a pedestrian along the urban route. The concentration of isobutane in ug/cu m was (location, median, mean, maximum): (a) in-vehicle, 0.5, 9.1, 281.7; (b) fixed site, 1.7, 3.9, 43.4; (c) car exterior, 0.2, 8.5, 56.0; (d) sidewalk, 6.4, 8.0, 22.0. The in-vehicle median concentration was 9.0 ug/cu m for urban driving, 2.2 ug/cu m for rural driving, and below the detection limit for interstate driving(1).

URBAN/SUBURBAN: Results of year-round sampling (24-hr samples every 6th day) of ambient air for isobutane at a representative site in Washington DC (3/90-3/91): 92.96% frequency, max 3.8 ppb, median 1.26 ppb, mean 1.4 ppb, SD 0.85 ppb(1). Concentration of isobutane in 39 U.S. cities between 1984-1986 (n = 836) in ppbC: median 14.9, 25th percentile 8.5, 75th percentile 23.5, min 1.2, max 647(5). The concentration of isobutane in marine air is 0.11 ppb(2) and in Sydney, Australia (1979-80) and Hamburg, Germany (1986-87) 4.7 ppb(3) and 3.8 ppb(2), respectively. The concentration of isobutane in Vienna, Austria (n = 5, street with heavy traffic, 1.5 m above the ground) was 7.1 ppbC with a standard deviation of 3.9 ppbC(6). The results of air monitoring for isobutane at Harwell, England between Mar 1973 and Aug 1974 (n = 63) was 0.37-3.58 ppb with a mean of 1.2 ppb(4). Levels of isobutane ranged from 3 to 10 ug/cu m in the air of Southern Taiwan, in sampling conducted in December 1998 and May 1999(7).

Residues of isobutane are exempted from the requirement of a tolerance when used in accordance with good agricultural practice as inert (or occasionally active) ingredients in pesticide formulations applied to growing crops or to raw agricultural commodities after harvest. Use: Propellant. Limit: None.

Residues of isobutane are exempted from the requirement of a tolerance when used in accordance with good agricultural practice as inert (or occasionally active) ingredients in pesticide formulations applied to animals. Use: Propellant. Limit: None.

Isobutane

1

10000

Flammable chemical that can be released at a facility.