2,2-Dimethylbutane

· 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.

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

General First Aid:

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

500.0 [ppm]

Wear self contained breathing apparatus for fire fighting if necessary.

Use water spray to cool unopened containers.

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

Over time, pressure may increase causing containers to burst. Handle and open container with care. Moisture sensitive.

Keep container tightly closed in a dry and well-ventilated place. Containers which are opened must be carefully resealed and kept upright to prevent leakage.

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

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.

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.

SRP: Contaminated protective clothing should be segregated in such a manner so that there is no direct personal contact by personnel who handle, dispose, or clean the clothing. The completeness of the cleaning procedures should be considered before the decontaminated protective clothing is returned for reuse by the workers. Contaminated clothing should not be taken home at the end of shift, but should remain at employee's place of work for cleaning.

Use personal protective equipment. 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.

The worker should immediately wash the skin when it becomes contaminated. /Hexane isomers (excluding n-Hexane)/

Work clothing that becomes wet should be immediately removed due to it flammability hazard (i.e., for liquids with a flash point <100 def F). /Hexane isomers (excluding n-Hexane)/

Excerpt from ERG Guide 128 [Flammable Liquids (Water-Immiscible)]:

Immediate precautionary measure

Hexane mainly affects the nervous system. It causes degeneration of the peripheral nervous system (and eventually the central nervous system), starting with damage to the nerve axons. Exposure to hexane may also damage the lungs and reproductive system. (L977, L978)

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 2100(SRC), determined from a log Kow of 3.82(2) and a regression-derived equation(3), indicates that 2,2-dimethylbutane is expected to have slight mobility in soil(SRC). Volatilization of 2,2-dimethylbutane from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 1.7 atm-cu m/mole(SRC) derived from its vapor pressure, 319 mm Hg(4), and water solubility, 21.2 mg/L(5). 2,2-Dimethylbutane is expected to volatilize from dry soil surfaces(SRC) based upon it's vapor pressure of 319 mm Hg at 25 °C(4). Under aerobic conditions, 2,2-dimethylbutane was shown to degrade after a 15 day lag period when tested as a mixture of light hydrocarbons in activated sludge (14% of the initial amount remained after 34 days of incubation); however, when tested as the single carbon source little degradation was observed (86% of the initial amount remained) suggesting that biodegradation may occur via co-metabolism(6).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 2100(SRC), determined from a log Kow of 3.82(2) and a regression-derived equation(3), indicates that 2,2-dimethylbutane 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 1.7 atm-cu m/mole(SRC), derived from its vapor pressure, 319 mm Hg(5), and water solubility, 2.12 mg/L(6). Using this Henry's Law constant and an estimation method(7), volatilization half-lives for a model river and model lake are 57 minutes and 3.7 days, respectively(SRC). According to a classification scheme(8), an estimated BCF of 150(SRC), from its log Kow(2) and a regression-derived equation(3), suggests the potential for bioconcentration in aquatic organisms is high(SRC). Under aerobic conditions, 2,2-dimethylbutane was shown to degrade after a 15 day lag period when tested as a mixture of light hydrocarbons in activated sludge (14% of the initial amount remained after 34 days of incubation); however, when tested as the single carbon source little degradation was observed (86% of the initial amount remained) suggesting that biodegradation may occur via co-metabolism(9).

ATMOSPHERIC FATE: 2,2,-Dimethylbutane, which has a vapor pressure of 319 mm Hg at 25 °C(1), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase 2,2-dimethylbutane 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 7 days(2), calculated from its rate constant of 2.32X10-12 cu cm/molecule-sec at 25 °C(3). 2,2-Dimethylbutane 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).

Hexane's toxicity is caused by it neurotoxic metabolite, 2,5-hexanedione. It damages the central and peripheral nervous system by causing axonal swelling and degeneration. 2,5-Hexanedione also reacts with lysine side-chain amino groups in axonal cytoskeletal proteins to form pyrroles. This results in neurofilament cross-linking and loss of function. (L175)

Breathing large amounts of hexane causes numbness in the feet and hands, followed by muscle weakness in the feet and lower legs. Continued exposure may lead to paralysis of the arms and legs. However, if removed from the exposure, recovery occurs in 6 months to a year. Inhalation of high concentrations produces first a state of mild euphoria, followed by somnolence with headaches and nausea. (L175, A121)

In Southern California, the 2,2-dimethylbutane profile for various emissions for vehicle exhaust was 0.44, 0.35, 1.01, 0.00, 0.85, and 1.73 wt% for: an EPA 46 car study, mean composite of 13 samples from the Caldecott Tunnel, cold start, stabilized, hot start, and from an older fleet, respectively(1). The average concentration of 2,2-dimethylbutane in the exhaust of 6 cars in the UK, 1988, was 1733 ppb(2). Gasoline engine exhaust (noncatalyst and catalyst equipped), and unburned gasoline (whole and headspace vapors) profiles include 2,2-dimethylbutane at concentrations of 0.3, 0.6, 0.2, and 0.3 wt%, respectively(3). Source composition profiles for exhaust from an FTP test of 46 in-use passenger vehicles for 1975-1982 model years, Vancouver gasoline, Vancouver gasoline vapor, Whatcom County gasoline and Whatcom County gasoline vapor included 2,2-dimethylbutane at 0.440, 0.218, 0.334, 0.192, 0.345% NMHC (non-methane hydrocarbons)(4). Emission rates of 2,2-dimethylbutane from light-duty and heavy-duty vehicles in the Fort McHenry tunnel(Baltimore, MD; collected June 1992) were measured as 4.5 and 15.9 mg/vehicle-mile, respectively; air concentrations at the east portal ranged from 1.9 to 67.8 ppbC. Emission rates of 2,2-dimethylbutane from light-duty and heavy-duty vehicles in the Tuscarora tunnel (Pennsylvania; collected September 1992) were measured as 2.3 and 12.1 mg/vehicle-mile, respectively; air concentrations ranged from 9.4 to 2.1 ppbC (5). 2,2-Dimethylbutane was emitted from the tailpipe of automobiles at a rate of 800 ug 2,2-dimethylbutane per kilometer (vehicles equipped with catalytic converters) and 195,000 ug 2,2-dimethylbutane per kilometer (vehicles without catalytic converters)(6). Vehicle emissions were analyzed in the Maria Maluf Tunnel in Sao Paulo, Brazil in May 2004. Average emission factors for 2,2-dimethylbutane were reported; May 5 morning, 10.2 mg/kg; May 5 evening, 16.4 mg/kg; May 6 morning, 122.9 mg/kg; May 6 evening, 26.2 mg/kg(7).

The Koc of 2,2-dimethylbutane is estimated as 2100(SRC), using a log Kow of 3.82(1) and a regression-derived equation(2). According to a classification scheme(3), this estimated Koc value suggests that 2,2-dimethylbutane is expected to have slight mobility in soil.

URBAN/SUBURBAN: The 2,2-dimethylbutane concentration ranged from 0 to 1 ppbV at a downtown Los Angeles location where it was detected in 4 of 17 samples in the Fall of 1981(1). The average concentration of 2,2-dimethylbutane at street level in London, 1988, was 16 ppb(2). The average and range of concentrations of 2,2-dimethylbutane measured in southern California over September 8-9, 1993 were 0.90 and 0.00-2.30 ug/cu m, respectively(3). 2,2-dimethylbutane has been detected in roadway air, airport facility air, and 'near' aircraft air in concentrations of 0.495, 0.50, and 0.172 ppb, respectively(4). 2,2-Dimethylbutane was detected at a mean concentration of 0.8 mg/cu m in the atmosphere of Porto Alegre, Brazil from March 1996 to April 1997(5). The arithmetic and geometric means were 47.9 and 43.9 ppbC, respectively, for the atmospheric 2,2-dimethylbutane content at urban locations in NW England(6). 2,2-dimethylbutane was detected at a mean concentration of 1.1 ug/cu m around the Los Angeles, CA area during a smog event on September 8-9, 1993(7).

RURAL/REMOTE: For the atmospheric 2,2-dimethylbutane content at rural locations in NW England, the arithmetic and geometric means were 1.8 and 1.8 ppbC, respectively(1).

SOURCE DOMINATED: In oil field emissions measured in Tulsa, OK, 2,2-dimethylbutane was detected at average concentration of 7.0 ppbC(1). The arithmetic and geometric means were 11.2 and 4.4 ppbC, respectively, for the atmospheric 2,2-dimethylbutane content at polluted rural locations in northwest England(2). 2,2-Dimethylbutane was detected in air samples collected in June 2004 from a gasoline service station located in Brazil at an average concentration of 19.5 ug/cu m(3).

AEROBIC: Under aerobic conditions, 2,2-dimethylbutane was shown to degrade after a 15 day lag period when tested as a mixture of light hydrocarbons in activated sludge (14% of the initial amount remained after 34 days of incubation). However, when tested as the single carbon source little degradation was observed (86% of the initial amount remained; comparable to the abiotic control where 89% remained) suggesting that its degradation may occur via co-metabolism(1). In another aerobic biodegradation study of gasoline hydrocarbons in water from a domestic sewage treatment plant, a degradation half-life for 2,2-dimethylbutane was calculated as 26.5 days(2). Under optimal conditions, biodegradation results for gasoline in activated sludge indicate that 2,2-dimethylbutane constituted a recalcitrant portion of the mixture(3).

AEROBIC: Incubation with natural flora in the groundwater - in presence of the other components of high-octane gasoline (100 uL/L): biodegradation: 25% after 192 hr at 13 °C (initial concentration 0.28 uL/L).

PURE CULTURE: Using the Clark oxygen electrode, a resting cell suspension of Corynebacterium sp. oxidized 2,2-dimethylbutane with an activity of 41% that of n-octane; the study indicated that the compound was utilized as a growth substrate by the microorganism(1). Therefore, this compound may have the potential to biodegrade, but is not expected to biodegrade rapidly(SRC).