2-Methylpentane

Fire Extinguishing Agents Not to Be Used: Water may be ineffective

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

Use alcohol-resistant foam, powder, carbon dioxide, water. In case of fire: keep drums, etc., cool by spraying with water.

Fresh air, rest. Refer for medical attention.

Remove contaminated clothes. Rinse and then wash skin with water and soap.

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

Rinse mouth. Give nothing to drink. Do NOT induce vomiting. Refer immediately for medical attention.

INHALATION: maintain respiration, give oxygen if needed.

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

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.

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

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

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.

Evacuate danger area! Consult an expert! Personal protection: filter respirator for organic gases and vapours of low boiling point adapted to the airborne concentration of the substance. Remove all ignition sources. Ventilation. Do NOT wash away into sewer. Do NOT let this chemical enter the environment. Collect leaking and spilled liquid in sealable non-plastic containers as far as possible. Absorb remaining liquid in sand or inert absorbent. Wash away remainder with plenty of water. Then store and dispose of according to local regulations.

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

SRP: The scientific literature for the use of contact lenses in industry is conflicting. The benefit or detrimental effects of wearing contact lenses depend not only upon the substance, but also on factors including the form of the substance, characteristics and duration of the exposure, the uses of other eye protection equipment, and the hygiene of the lenses. However, there may be individual substances whose irritating or corrosive properties are such that the wearing of contact lenses would be harmful to the eye. In those specific cases, contact lenses should not be worn. In any event, the usual eye protection equipment should be worn even when contact lenses are in place.

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 its flammability hazard (i.e., for liquids with a flash point <100 °F). /Hexane isomers (excluding n-Hexane)/

2-Methylpentane was detected in 3 of 12 breath samples collected in New Jersey during a pilot broad spectrum analysis of exposure to chemicals conducted by the EPA's Total Exposure Assessment Methodology (TEAM) Study(1). 2-Methylpentane was detected in the urine of 22 exposed workers(2). During a German Environmental Survey, 2-methylpentane was detected above 1 ug/cu m in 113 personal exposure samples collected from individuals in the Western part of Germany(3). The 95th percentile and geometric mean concentrations in these samples were 150 and 16.3 ug/cu m, respectively(3). From alveolar breath data after 1 individual was exposed to 2000 ug/cm m 2-methylpentane(site: home garage with fuel handling and wood staining; duration: 2.2hours), half-lives were calculated using a one compartment model to be 0.86 hours and two compartment model to be 0.21 hours and 3.18 hours(3). In the same study, whole breath data was also used to calculate half-lives for 2-methylpentane using the one compartment model 1.02 hours and two compartment model 0.26 hours and 2.25 hours(3).

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 610(SRC), determined from a structure estimation method(2), indicates that 2-methylpentane is expected to have low mobility in soil(SRC). Volatilization of 2-methylpentane 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), based upon its vapor pressure, 211 mm Hg(3), and water solubility, 14.2 mg/L(4). 2-Methylpentane is expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(3). A 93% of theoretical BOD using activated sludge in the Japanese MITI screening test(5) suggests that biodegradation is an important environmental fate process in soil(SRC).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 110(SRC), determined from a structure estimation method(2), indicates that 2-methylpentane is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(3) based upon an estimated Henry's Law constant of 1.71 atm-cu m/mole(SRC), derived from its vapor pressure, 211 mm Hg(4), and water solubility, 14.2 mg/L(5). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 3 hours and 4 days, respectively(SRC). According to a classification scheme(6), an estimated BCF of 61(SRC), from an estimated log Kow of 3.21(2) and a regression-derived equation(2), suggests the potential for bioconcentration in aquatic organisms is moderate(SRC). A 93% of theoretical BOD using activated sludge in the Japanese MITI screening test(7) suggests that biodegradation is an important environmental fate process in water(SRC).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), 2-methylpentane, which has a vapor pressure of 211 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase 2-methylpentane 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 2.9 days(SRC), calculated from its rate constant of 5.57x10-12 cu cm/molecule-sec at 25 °C(3). Degradation is much faster under photochemical smog conditions with a 26.4% loss in 5 hr being reported in one study(4). 2-Methylpentane 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).

2-Methylpentane has been detected as a volatile in nectarines(1). 2-Methylpentane has been identified as a volatile component of beef (2). 2-Methylpentane comprised of 0.47, 0.08, 0.62 and 0.67% of nonmethane organic carbon emissions monitored in restaurants, tortillerias, rotisseries and near food frying operations in Mexico City, respectively(3). 2-Methylpentane was detected in emissions during hamburger meat charbroiling at concentrations of 22,000 ug/kg(4).

The substance can be absorbed into the body by inhalation of its vapour and through the skin.

Oral (L175) ;inhalation (L175) ;dermal (L175)

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)

Cough. Headache. Dizziness. Unconsciousness.

Redness.

Redness. Pain.

Aspiration hazard! Abdominal pain. Nausea. Vomiting. Diarrhoea. Further see Inhalation.

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)

The average concentration of 2-methylpentane in the exhaust of 6 cars in the UK, 1988, was 6452 ppb(1). 2-Methylpentane was found in waste gases from semiconductor manufacturing processes at factories in Hsin-Chu, Taiwan from October 2000 to September 2001(2). Hot soak (2-methylpentane=4.62 weight%) and cold-start (2-methylpentane = 4.40 weight%) emission profiles of an integrated sample of vehicles were measured inside a parking garage in Chicago during March 1990; hot-soak emissions were monitored after the morning rush hour while cold-start emissions were measured when the vehicles left for the evening rush hour(3). In Southern California, the profile for various emissions of vehicle exhaust included 2-methylpentane at 1.91, 3.17, 3.47, 3.69, 6.40, and 4.94 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(4). 2-Methylpentane was identified in the exhaust of small engines at 1.4% and 1.56% of the total emissions using baseline gasoline with a composition profile which includes 2-methylpentane at 3.44 wt% and reformulated gasoline with a composition profile which includes 2-methylpentane at 3.62 wt%, respectively(5). Gasoline engine exhaust (noncatalyst and catalyst equipped), unburned gasoline (whole and headspace vapors) and commercial jet aircraft exhaust profiles include 2,-methylpentane at concentrations of 1.3, 2.1, 3.3, 2.8 and 0.4 wt%, respectively(6). 2-Methylpentane was detected in the effluent of a waste incinerator in Germany at a concentration of 3.20 ug/cu m(7). 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-methylpentane at 1.910, 3.816, 3.829, 2.483, and 2.910%, NMHC (non-methane hydrocarbons), respectively(8). Emission rates of 2-methylpentane from light-duty and heavy-duty vehicles in the Fort McHenry tunnel(Baltimore, MD; collected June 1992) were measured as 16.6 and 11.9 mg/vehicle-mile, respectively; air concentrations at the east portal ranged from 6.3 to 112.4 ppbC(9). Emission rates of 2-methylpentane from light-duty and heavy-duty vehicles in the Tuscarora tunnel (Pennsylvania; collected September 1992) were measured as 7.6 and 9.9 mg/vehicle-mile, respectively; air concentrations ranged from 2.5 to 17.7 ppbC (9). A mean concentration of 6452 ppbV was determined for 2-methylpentane from exhaust samples taken from 6 different UK cars(10). 2-Methylpentane was emitted from the tailpipe of automobiles at a rate of 6,310 ug 2-methylpentane per kilometer (vehicles equipped with catalytic converters) and 827,000 ug 2-methylpentane per kilometer (vehicles without catalytic converters)(11).

The average (standard deviation) composition of 2-methylpentane in the exhaust of 67 motor vehicles in Sidney Australia was 2.3% (0.4%) by weight(1). The percent 2-methylpentane of vehicle exhaust, gasoline vapor, petroleum refinery air, and petrochemical plant air in the Tokyo region was 3.8, 6.3, 3.7, and 1.5%(2). A study in the Chicago area yielded 2-methylpentane emission profiles (wt%) as (source, content): regular gas, 3.20; mid-grade gas, 2.34; premium gas 0.77(3). 2-Methylpentane was one of the most abundant compounds in gasoline with reported concentrations of 6.5% and 4.0% wt in summer and winter headspace vapor, respectively , and 3.9% and 3.3% wt in summer and winter liquid gasoline, respectively, as reported in a diurnal and seasonal variability analysis of gasoline-related volatile organic compound emissions in Riverside, California(4).

Using a structure estimation method based on molecular connectivity indices(1), the Koc of 2-methylpentane can be estimated to be 610(SRC). According to a classification scheme(2), this estimated Koc value suggests that 2-methylpentane is expected to have low mobility in soil. A sorption experiment using lignite samples resulted in a log Kd of 2.92 for 2-methylpentane(3).