2-methylpentane

H225: Highly Flammable liquid and vapor [Danger Flammable liquids]

H304: May be fatal if swallowed and enters airways [Danger Aspiration hazard]

H315: Causes skin irritation [Warning Skin corrosion/irritation]

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

H411: Toxic to aquatic life with long lasting effects [Hazardous to the aquatic environment, long-term hazard]

P210, P233, P240, P241, P242, P243, P261, P264, P271, P273, P280, P301+P316, P302+P352, P303+P361+P353, P304+P340, P319, P321, P331, P332+P317, P362+P364, P370+P378, P391, P403+P233, P403+P235, P405, and P501 (click each P-code to see the statement)

H225 (99.3%): Highly Flammable liquid and vapor [Danger Flammable liquids]

H304 (99.8%): May be fatal if swallowed and enters airways [Danger Aspiration hazard]

H315 (98.8%): Causes skin irritation [Warning Skin corrosion/irritation]

H336 (99.5%): May cause drowsiness or dizziness [Warning Specific target organ toxicity, single exposure; Narcotic effects]

H411 (93.8%): Toxic to aquatic life with long lasting effects [Hazardous to the aquatic environment, long-term hazard]

Aggregated GHS information provided per 416 reports by companies from 33 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.

H304 (100%): May be fatal if swallowed and enters airways [Danger Aspiration hazard]

H315 (100%): Causes skin irritation [Warning Skin corrosion/irritation]

H336 (100%): May cause drowsiness or dizziness [Warning Specific target organ toxicity, single exposure; Narcotic effects]

H411 (100%): Toxic to aquatic life with long lasting effects [Hazardous to the aquatic environment, long-term hazard]

P261, P264, P271, P273, P280, P301+P316, P302+P352, P304+P340, P319, P321, P331, P332+P317, P362+P364, P391, P403+P233, P405, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 39 reports by companies from 2 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

P210, P233, P240, P241, P242, P243, P264, P280, P302+P352, P303+P361+P353, P321, P332+P317, P362+P364, P370+P378, P403+P235, and P501 (click each P-code to see the statement)

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.

ASPIRATION: enforce bed rest; give oxygen.

INGESTION: do NOT induce vomiting; call a doctor.

EYES: wash with copious amount of water.

SKIN: wipe off, wash with soap and water. (USCG, 1999)

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

Refer to the "General First Aid" section. Specific First Aid: Wash skin with soap and water. 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)

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

Fire Extinguishing Agents: Foam, carbon dioxide, or dry chemical (USCG, 1999)

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

CAUTION: The majority of these products have a very low flash point. Use of water spray when fighting fire may be inefficient. CAUTION: For mixtures containing alcohol or polar solvent, alcohol-resistant foam may be more effective.

SMALL FIRE: Dry chemical, CO2, water spray or regular foam. If regular foam is ineffective or unavailable, use alcohol-resistant foam.

LARGE FIRE: Water spray, fog or regular foam. If regular foam is ineffective or unavailable, use alcohol-resistant foam. Avoid aiming straight or solid streams directly onto the product. If it can be done safely, move undamaged containers away from the area around the fire.

FIRE INVOLVING TANKS, RAIL TANK CARS OR HIGHWAY 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. For petroleum crude oil, do not spray water directly into a breached tank car. This can lead to a dangerous boil over. 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)

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

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)]:

IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area for at least 50 meters (150 feet) in all directions.

LARGE SPILL: Consider initial downwind evacuation for at least 300 meters (1000 feet).

FIRE: If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2024)

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.

Ventilation. Collect leaking and spilled liquid in sealable containers as far as possible. Absorb remaining liquid in sand or inert absorbent. Then store and dispose of according to local regulations. Do NOT wash away into sewer.

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: 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)/

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

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. Prevent entry into waterways, sewers, basements or confined areas. A vapor-suppressing foam may be used to reduce vapors. Absorb or cover with dry earth, sand or other non-combustible material and transfer to containers. Use clean, non-sparking tools to collect absorbed material.

LARGE SPILL: Dike far ahead of liquid spill for later disposal. Water spray may reduce vapor, but may not prevent ignition in closed spaces. (ERG, 2024)

Fireproof. Cooled. Separated from strong oxidants. Store in an area without drain or sewer access. Do NOT store or transport in containers made from plastic.

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.

500.0 [ppm]

1000 [ppm]

11000 [ppm]

66000 [ppm]

100 ppm (350 mg/m³)

510 ppm (1800 mg/m³) [15 minute]

200.0 [ppm]

8 hr Time Weighted Avg (TWA): 500 ppm; 15 min Short Term Exposure Limit (STEL): 1000 ppm.

500 ppm as TWA; 1000 ppm as STEL.

500 ppm [1979]

1000 ppm [1979]

1800 mg/m

Chronic Inhalation: 0.6 ppm (L134)

A harmful contamination of the air can be reached rather quickly on evaporation of this substance at 20 °C.

The substance and the vapour are mildly irritating to the eyes, respiratory tract and skin. If swallowed the substance easily enters the airways and could result in aspiration pneumonitis. The substance may cause effects on the central nervous system. This may result in lowering of consciousness.

The substance defats the skin, which may cause dryness or cracking. Repeated or prolonged contact with skin may cause dermatitis.

Eye protection (as for gasoline). (USCG, 1999)

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

Wear positive pressure self-contained breathing apparatus (SCBA). Structural firefighters' protective clothing provides thermal protection but only limited chemical protection. (ERG, 2024)

Wear appropriate personal protective clothing to prevent skin contact. /Hexane isomers (excluding n-Hexane)/

Wear appropriate eye protection to prevent eye contact. /Hexane isomers (excluding n-Hexane)/

Respirator Recommendations: Up to 1000 ppm: /Hexane isomers (excluding n-Hexane)/ [Table#2855]

Respirator Recommendations: Up to 2500 ppm: /Hexane isomers (excluding n-Hexane)/ [Table#2856]

For more Personal Protective Equipment (PPE) (Complete) data for 2-METHYLPENTANE (7 total), please visit the HSDB record page.

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). Do NOT use compressed air for filling, discharging, or handling. Use non-sparking handtools.

Use ventilation, local exhaust or breathing protection.

Protective gloves.

Wear safety goggles.

Do not eat, drink, or smoke during work.

Watery liquid with a gasoline-like odor, Floats on water. Produces an irritating vapor. (USCG, 1999)

Methyl pentane appears as colorless liquid. Isomers (2-methyl, 3-methyl) are possible and present in technical mixtures or singly for research purposes. Used in organic synthesis and as a solvent.

Liquid; Gas Vapor

Colorless liquid with a faint petroleum odor; [CHEMINFO]

COLOURLESS LIQUID WITH CHARACTERISTIC ODOUR.

Clear liquids with mild, gasoline-like odors.

Colorless liquid

Liquid or oil

140.5 °F at 760 mmHg (USCG, 1999)

60.21 °C

122-145 °F

60.3 °C @760 [mm Hg]

-244.6 °F (USCG, 1999)

-153.6 °C

-245 to -148 °F

-20 °F (USCG, 1999)

<20 °F (<-7 °C) (Closed cup)

-32 °C c.c.

-54 to 19 °F

In water, 14 mg/L

Soluble in ethanol, diethyl ether; miscible in acetone, benzene, chloroform

Solubility in water: none

0.653 at 68 °F (USCG, 1999) - Less dense than water; will float

0.6550 g/cu cm at 25 °C

Relative density (water = 1): 0.65

0.65-0.66

0.669 @25 °C

3.00 (Air = 1)

Relative vapor density (air = 1): 3.0

310.2 mmHg (USCG, 1999)

211.0 [mmHg]

VP: 40 mm Hg at 41.6 °C

211 mm Hg at 25 °C

Vapor pressure, kPa at 20 °C: 23

310.2 mmHg

400 [mm Hg] @41.6 °C

3.2 (estimated)

Stable under recommended storage conditions.

585 °F (USCG, 1999)

583 °F (306 °C)

Highly flammable.

Highly flammable. Easily ignited by heat, sparks or flames. Vapors may form explosive mixtures with air. Vapors may travel to source of ignition and flash back. Insoluble in water.

Hydrocarbons, Aliphatic Saturated

Highly Flammable

Saturated aliphatic hydrocarbons, such as ISOHEXANE, may be incompatible with strong oxidizing agents like nitric acid. Charring of the hydrocarbon may occur followed by ignition of unreacted hydrocarbon and other nearby combustibles. In other settings, aliphatic saturated hydrocarbons are mostly unreactive. They are not affected by aqueous solutions of acids, alkalis, most oxidizing agents, and most reducing agents.

METHYL PENTANE may be incompatible with strong oxidizing agents like nitric acid. Charring may occur followed by ignition of unreacted material and nearby combustibles. In other settings, mostly unreactive. Not affected by aqueous solutions of acids, alkalis, most oxidizing agents, and most reducing agents. When heated sufficiently or when ignited in the presence of air, oxygen or strong oxidizing agents, burns exothermically.

Strong oxidizing agents.

2-Methylpentane

B*: Compounds that form peroxides on concentration (distillation/evaporation)

9 samples had &lt;10 to &gt;100 ppm peroxide; age &gt;9 yrs (petroleum ether)

Management of time-sensitive chemicals (JCHAS)

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)

No indication of carcinogenicity to humans (not listed by IARC).

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)

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

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

Neurotoxin - Acute solvent syndrome

ACGIH Carcinogen - Confirmed Animal.

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 or lorazepam ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Aliphatic hydrocarbons and related compounds/

Determination of these cmpd showed that alveolar & blood monitoring can replace environmental monitoring of solvents.

/OTHER TOXICITY INFORMATION/ A human eye irritant.

/LABORATORY ANIMALS: Subchronic or Prechronic Exposure/ Thirty rats oral admin daily for 8 wk 2-methylpentane diluted in olive oil. Methylpentane was less neurotoxic than n-hexane.

/LABORATORY ANIMALS: Chronic Exposure or Carcinogenicity/ Over 9 mo period, 20 rabbits exposed to 2-methylpentane 6 hr/day/6 days/wk. No symptoms of early polyneuropathy were found. Butyrylcholine esterase values were lower.

The substance is toxic to aquatic organisms. It is strongly advised not to let the chemical enter into the environment.

2-Methylpentane's production and use in organic synthesis may result in its release to the environment through various waste streams; its use as a solvent may result in its direct release to the environment. 2-Methylpentane may also be released to the environment as a fugitive emission in motor engine exhaust; atmospheric concentration of 2-methylpentane is strongly related to traffic. 2-Methylpentane occurs naturally in petroleum and may be released to the environment from natural petroleum seepages or as fugitive emissions or spills wherever petroleum products are refined, stored, transferred or used. 2-Methylpentane is also a natural plant volatile. If released to air, a vapor pressure of 211 mm Hg at 25 °C indicates 2-methylpentane will exist solely as a vapor in the atmosphere. Vapor-phase 2-methylpentane 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 2.9 days. 2-Methylpentane 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-methylpentane is expected to have low mobility based upon an estimated Koc of 610. Volatilization from moist soil surfaces is expected to be an important fate process based upon an estimated Henry's Law constant of 1.7 atm-cu m/mole. 2-Methylpentane may volatilize from dry soil surfaces based upon its vapor pressure. Utilizing the Japanese MITI screening test, 93% of the Theoretical BOD was reached in 4 weeks indicating that biodegradation is an important environmental fate process in soil and water. If released into water, 2-methylpentane may adsorb to suspended solids and sediment based upon the estimated Koc value. 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 3 hours and 4 days, respectively. An estimated BCF of 61 suggests the potential for bioconcentration in aquatic organisms is moderate. 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 2-methylpentane may occur through inhalation and dermal contact with this compound at workplaces where 2-methylpentane is produced or used. Monitoring data indicate that the general population may be exposed to 2-methylpentane via inhalation of ambient air and dermal contact with consumer products containing 2-methylpentane. (SRC)

2-Methylpentane occurs naturally in petroleum and gas and as a plant volatile(1,2). Emissions would therefore occur as a result of natural oil seepages or gas vents and emissions from vegetation. Forest fires are another emission source(1).

2-Methylpentane's production and use in organic synthesis(1) may result in its release to the environment through various waste streams; its use as a solvent(1) may result in its direct release to the environment. 2-Methylpentane may also be released to the environment as a fugitive emission in motor engine exhaust; atmospheric concentration of 2-methylpentane is strongly related to traffic(2).

2-Methylpentane is found in sources associated with petroleum products such as petroleum manufacture, natural gas, turbines, and automobiles(4). Emissions will occur from the evaporation of petroleum during transfer, transport and storage of petroleum products and evaporation of gasoline from carburetors, gas tanks, and during refueling of motor vehicles(2). The fact that 2-methylpentane in cities is associated with traffic is clearly demonstrated by the similarly of auto exhaust profiles compared with ambient air profiles in areas of high traffic in Bangkok City(3). 2-Methylpentane is also used as a solvent(5) and will be released to the atmosphere as a result of solvent evaporation. 2-Methylpentane was a volatile component of a stainless steel polish cleaner and carpet glue(1).

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).

AEROBIC: Indigenous soil microbes will biodegrade petroleum hydrocarbons under aerobic conditions(1). A quarter of the microorganisms isolated from gasoline-contaminated groundwater, most notably of the Nocardia sp., supported growth of 2-methylpentane(2). Generally iso-alkanes are significantly more resistant to microbial attack than n-alkanes(3). However, a soil microorganism, Corynebacterium sp. oxidized 2-methylpentane, at about the same rate as n-pentane, although at a significantly lower rate than n-hexane(3). A mean half-life of 5.9 days was reported for all detectable hydrocarbons in an aerobic biodegradation study of gasoline in water from a domestic sewage treatment plant(4). The biodegradation half-lives of the C6-saturates compound group (n-hexane, 2-methylpentane, 3-methylpentane, methylcylcopentane and cyclohexane), determined from biodegradation tests with water accommodated fractions(WAF) of Statjofrd fresh oil, Aquila fresh oil, and Marine diesel in seawater at 13 °C, were 2.8, 1.7, and 3.5 days respectively (without correction for lag phase) (5). The mean half-life from results for all three oils was determined to be 2.7 days for the C6-saturates group(5). 2-Methylpentane, and 10 other components of gasoline were completely degraded in a screening study using an activated sludge inoculum in less than 34 days(6). A mixture containing isopentane, pentane, cyclopentane, 2,3-dimethylbutane, 2-methylpentane, 3-methylpentane, and cyclohexane, showed little degradation over the course of 30 days in a sediment/groundwater obtained from a contaminated jet fuel site in Oscoda, MI(7). 2-Methylpentane, present at 100 mg/L, reached 93% of its theoretical BOD in 4 weeks using an activated sludge inoculum at 30 mg/L in a screening test assessing biodegradation in water(8). Therefore, 2-methylpentane is confirmed to be readily biodegradable according to the standard test of the Japanese Ministry of Industry and Trade (MITI) (8).

ANAEROBIC: Biodegradation of petroleum hydrocarbons occurs under anaerobic conditions at a slower rate than aerobic degradation, particularly by sulfur-reducing bacteria(1).

The rate constant for the vapor-phase reaction of 2-methylpentane with photochemically-produced hydroxyl radicals has been determined as 5.57x10-12 cu cm/molecule-sec at 25 °C(1). This corresponds to an atmospheric half-life of about 2.9 days at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(SRC). 2-Methylpentane has low to moderate photochemical reactivity(2). Smog chamber studies of the NOX-air photooxidation of 2-methylpentane, resulted in a 26.4% depletion of 2-methylpentane in 5 hr(2). In the Houston Oxidant Field Study, the diurnal patterns of NO2, O3, and 2-methylpentane concentrations suggest that the photochemical reaction of 2-methylpentane and NO2 contribute to elevated ozone levels(3). The order-of-magnitude lower concentration of 2-methylpentane in the arctic summer compared with the spring is explained by differences in levels of sunlight and photochemical loss(4). 2-Methylpentane is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(5). 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).

An estimated BCF of 61 was calculated in fish for 2-methylpentane(SRC), using an estimated log Kow of 3.21(1) and a regression-derived equation(1). According to a classification scheme(2), this BCF suggests the potential for bioconcentration in aquatic organisms is moderate(SRC).

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).

The Henry's Law constant for 2-methylpentane is estimated as 1.7 atm-cu m/mole(SRC) derived from its vapor pressure, 211 mm Hg(1), and water solubility, 14.2 mg/L(2). This Henry's Law constant indicates that 2-methylpentane is expected to volatilize rapidly from water surfaces(3). 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)(3) is estimated as 3 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)(3) is estimated as 4 days(SRC). 2-Methylpentane's estimated Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC). The potential for volatilization of 2-methylpentane from dry soil surfaces may exist (SRC) based upon a vapor pressure of 211 mm Hg(1).

DRINKING WATER: 2-Methylpentane was detected in tap water 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).

SURFACE WATER: 2-Methylpentane was measured in eight samples of sea water taken during a cruise on the Indian Ocean; concentrations ranged from 0.03-0.79 nanoliters of vapor per liter of water at 30 °C(1).

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).

Methylpentane (isomer unspecified) was identified in air at four to five locations in 4 New Jersey hazardous waste sites on the National Priorities list and one landfill; concentrations were not reported(1). Methylpentane was identified in 12 of 63 industrial waste water effluents, all at concentration levels <10 ug/L(2).

2-Methylpentane was identified in effluents from household cookstoves used in urban and rural China. Molar emission ratios in CO2 (X10-7) were (stove type): 1.27 (honeycomb briquette-metal without a flue); not detected (honeycomb briquette-improved metal without a flue); 0.615 (coal briquette-metal); 36.9 (washed coal powder-metal with a flue); 10.3 (unprocessed coal powder-metal with a flue); 0.347 (unprocessed coal-brick with a flue); not detected (wood-brick with a flue); not detected (wood-improved brick with a flue); 0.222 (wheat-brick with a flue); not detected (maize-brick with a flue); not detected (maize-improved brick with a flue); not detected (kerosene-wick without a flue); not detected (Liquefied Petroleum Gas-traditional without a flue); 0.125 (coal-gas traditional without a flue); 0.514 (natural gas-traditional without a flue)(1).

2-Methylpentane was a volatile component of a stainless steel polish cleaner and carpet glue(1). Emissions will occur from the evaporation of petroleum during transfer, transport and storage of petroleum products and evaporation of gasoline from carburetors, gas tanks, and during refueling of motor vehicles(2). The fact that 2-methylpentane in cities is associated with traffic is clearly demonstrated by the similarity of auto exhaust profiles compared with ambient air profiles in areas of high traffic in Bangkok City(3). 2-Methylpentane is found in sources associated with petroleum products such as petroleum manufacture, natural gas, turbines, and automobiles(4). 2-Methylpentane has been identified as a component in JP-4 Standard jet fuel(5). 2-Methylpentane has been detected in 87 octane and 89 octane gasoline, having concentrations of 3.40 and 2.58 ppb, respectively(6). 2-Methylpentane is a component of unleaded gasoline, 3.93% by weight(7). 2-Methylpentane has been detected in headspace air samples of household products such as wax paste for furniture, floors and linoleum(8).

The substance is toxic to aquatic organisms. It is strongly advised not to let the chemical enter into the environment.

2-Methylpentane's production and use in organic synthesis may result in its release to the environment through various waste streams; its use as a solvent may result in its direct release to the environment. 2-Methylpentane may also be released to the environment as a fugitive emission in motor engine exhaust; atmospheric concentration of 2-methylpentane is strongly related to traffic. 2-Methylpentane occurs naturally in petroleum and may be released to the environment from natural petroleum seepages or as fugitive emissions or spills wherever petroleum products are refined, stored, transferred or used. 2-Methylpentane is also a natural plant volatile. If released to air, a vapor pressure of 211 mm Hg at 25 °C indicates 2-methylpentane will exist solely as a vapor in the atmosphere. Vapor-phase 2-methylpentane 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 2.9 days. 2-Methylpentane 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-methylpentane is expected to have low mobility based upon an estimated Koc of 610. Volatilization from moist soil surfaces is expected to be an important fate process based upon an estimated Henry's Law constant of 1.7 atm-cu m/mole. 2-Methylpentane may volatilize from dry soil surfaces based upon its vapor pressure. Utilizing the Japanese MITI screening test, 93% of the Theoretical BOD was reached in 4 weeks indicating that biodegradation is an important environmental fate process in soil and water. If released into water, 2-methylpentane may adsorb to suspended solids and sediment based upon the estimated Koc value. 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 3 hours and 4 days, respectively. An estimated BCF of 61 suggests the potential for bioconcentration in aquatic organisms is moderate. 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 2-methylpentane may occur through inhalation and dermal contact with this compound at workplaces where 2-methylpentane is produced or used. Monitoring data indicate that the general population may be exposed to 2-methylpentane via inhalation of ambient air and dermal contact with consumer products containing 2-methylpentane. (SRC)

2-Methylpentane occurs naturally in petroleum and gas and as a plant volatile(1,2). Emissions would therefore occur as a result of natural oil seepages or gas vents and emissions from vegetation. Forest fires are another emission source(1).

2-Methylpentane's production and use in organic synthesis(1) may result in its release to the environment through various waste streams; its use as a solvent(1) may result in its direct release to the environment. 2-Methylpentane may also be released to the environment as a fugitive emission in motor engine exhaust; atmospheric concentration of 2-methylpentane is strongly related to traffic(2).

2-Methylpentane is found in sources associated with petroleum products such as petroleum manufacture, natural gas, turbines, and automobiles(4). Emissions will occur from the evaporation of petroleum during transfer, transport and storage of petroleum products and evaporation of gasoline from carburetors, gas tanks, and during refueling of motor vehicles(2). The fact that 2-methylpentane in cities is associated with traffic is clearly demonstrated by the similarly of auto exhaust profiles compared with ambient air profiles in areas of high traffic in Bangkok City(3). 2-Methylpentane is also used as a solvent(5) and will be released to the atmosphere as a result of solvent evaporation. 2-Methylpentane was a volatile component of a stainless steel polish cleaner and carpet glue(1).

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).

AEROBIC: Indigenous soil microbes will biodegrade petroleum hydrocarbons under aerobic conditions(1). A quarter of the microorganisms isolated from gasoline-contaminated groundwater, most notably of the Nocardia sp., supported growth of 2-methylpentane(2). Generally iso-alkanes are significantly more resistant to microbial attack than n-alkanes(3). However, a soil microorganism, Corynebacterium sp. oxidized 2-methylpentane, at about the same rate as n-pentane, although at a significantly lower rate than n-hexane(3). A mean half-life of 5.9 days was reported for all detectable hydrocarbons in an aerobic biodegradation study of gasoline in water from a domestic sewage treatment plant(4). The biodegradation half-lives of the C6-saturates compound group (n-hexane, 2-methylpentane, 3-methylpentane, methylcylcopentane and cyclohexane), determined from biodegradation tests with water accommodated fractions(WAF) of Statjofrd fresh oil, Aquila fresh oil, and Marine diesel in seawater at 13 °C, were 2.8, 1.7, and 3.5 days respectively (without correction for lag phase) (5). The mean half-life from results for all three oils was determined to be 2.7 days for the C6-saturates group(5). 2-Methylpentane, and 10 other components of gasoline were completely degraded in a screening study using an activated sludge inoculum in less than 34 days(6). A mixture containing isopentane, pentane, cyclopentane, 2,3-dimethylbutane, 2-methylpentane, 3-methylpentane, and cyclohexane, showed little degradation over the course of 30 days in a sediment/groundwater obtained from a contaminated jet fuel site in Oscoda, MI(7). 2-Methylpentane, present at 100 mg/L, reached 93% of its theoretical BOD in 4 weeks using an activated sludge inoculum at 30 mg/L in a screening test assessing biodegradation in water(8). Therefore, 2-methylpentane is confirmed to be readily biodegradable according to the standard test of the Japanese Ministry of Industry and Trade (MITI) (8).

ANAEROBIC: Biodegradation of petroleum hydrocarbons occurs under anaerobic conditions at a slower rate than aerobic degradation, particularly by sulfur-reducing bacteria(1).

The rate constant for the vapor-phase reaction of 2-methylpentane with photochemically-produced hydroxyl radicals has been determined as 5.57x10-12 cu cm/molecule-sec at 25 °C(1). This corresponds to an atmospheric half-life of about 2.9 days at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(SRC). 2-Methylpentane has low to moderate photochemical reactivity(2). Smog chamber studies of the NOX-air photooxidation of 2-methylpentane, resulted in a 26.4% depletion of 2-methylpentane in 5 hr(2). In the Houston Oxidant Field Study, the diurnal patterns of NO2, O3, and 2-methylpentane concentrations suggest that the photochemical reaction of 2-methylpentane and NO2 contribute to elevated ozone levels(3). The order-of-magnitude lower concentration of 2-methylpentane in the arctic summer compared with the spring is explained by differences in levels of sunlight and photochemical loss(4). 2-Methylpentane is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(5). 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).

An estimated BCF of 61 was calculated in fish for 2-methylpentane(SRC), using an estimated log Kow of 3.21(1) and a regression-derived equation(1). According to a classification scheme(2), this BCF suggests the potential for bioconcentration in aquatic organisms is moderate(SRC).

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).

The Henry's Law constant for 2-methylpentane is estimated as 1.7 atm-cu m/mole(SRC) derived from its vapor pressure, 211 mm Hg(1), and water solubility, 14.2 mg/L(2). This Henry's Law constant indicates that 2-methylpentane is expected to volatilize rapidly from water surfaces(3). 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)(3) is estimated as 3 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)(3) is estimated as 4 days(SRC). 2-Methylpentane's estimated Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC). The potential for volatilization of 2-methylpentane from dry soil surfaces may exist (SRC) based upon a vapor pressure of 211 mm Hg(1).

DRINKING WATER: 2-Methylpentane was detected in tap water 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).

SURFACE WATER: 2-Methylpentane was measured in eight samples of sea water taken during a cruise on the Indian Ocean; concentrations ranged from 0.03-0.79 nanoliters of vapor per liter of water at 30 °C(1).

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).

Methylpentane (isomer unspecified) was identified in air at four to five locations in 4 New Jersey hazardous waste sites on the National Priorities list and one landfill; concentrations were not reported(1). Methylpentane was identified in 12 of 63 industrial waste water effluents, all at concentration levels <10 ug/L(2).

2-Methylpentane was identified in effluents from household cookstoves used in urban and rural China. Molar emission ratios in CO2 (X10-7) were (stove type): 1.27 (honeycomb briquette-metal without a flue); not detected (honeycomb briquette-improved metal without a flue); 0.615 (coal briquette-metal); 36.9 (washed coal powder-metal with a flue); 10.3 (unprocessed coal powder-metal with a flue); 0.347 (unprocessed coal-brick with a flue); not detected (wood-brick with a flue); not detected (wood-improved brick with a flue); 0.222 (wheat-brick with a flue); not detected (maize-brick with a flue); not detected (maize-improved brick with a flue); not detected (kerosene-wick without a flue); not detected (Liquefied Petroleum Gas-traditional without a flue); 0.125 (coal-gas traditional without a flue); 0.514 (natural gas-traditional without a flue)(1).

2-Methylpentane was a volatile component of a stainless steel polish cleaner and carpet glue(1). Emissions will occur from the evaporation of petroleum during transfer, transport and storage of petroleum products and evaporation of gasoline from carburetors, gas tanks, and during refueling of motor vehicles(2). The fact that 2-methylpentane in cities is associated with traffic is clearly demonstrated by the similarity of auto exhaust profiles compared with ambient air profiles in areas of high traffic in Bangkok City(3). 2-Methylpentane is found in sources associated with petroleum products such as petroleum manufacture, natural gas, turbines, and automobiles(4). 2-Methylpentane has been identified as a component in JP-4 Standard jet fuel(5). 2-Methylpentane has been detected in 87 octane and 89 octane gasoline, having concentrations of 3.40 and 2.58 ppb, respectively(6). 2-Methylpentane is a component of unleaded gasoline, 3.93% by weight(7). 2-Methylpentane has been detected in headspace air samples of household products such as wax paste for furniture, floors and linoleum(8).

The median 2-methylpentane concentration at rural/remote (10 samples), urban/suburban (46 samples), and source dominate (59 samples) sites in the United States was 1.1, 4.2, and 3.1 ppb, respectively. The concentration for the 6 site studies ranged from 0.8 to 45 ppb(1).

URBAN/SUBURBAN: 2-Methylpentane was detected in 39 US cities from 1984 through 1986 (836 samples) 1.4-647 ppb, 25th percentile 10.2, median 17.9, 75th percentile 28.2 ppb(7). Los Angeles (23 days, morning samples) 8-28 ppb(2). Tulsa, OK (6 samples) 7.7-42.5 ppb(6). The concentration at a residential site in Houston, TX, removed from highways, (684 data points) was 28 and 272 ppb, mean and maximum, respectively(9). The average concentration between 6 and 9 am (72 data points) was 43 ppb(9). 2-Methylpentane was detected in NW England - urban samples 25.4 ppb, mean(1). Vienna, Austria 22.9 ppb - the concentration on top of a 52 m building was 47% that at ground level(3). Sidney, Australia (140 samples) 2.6 ppb, mean(4). 2-Methylpentane was identified, but not quantified, in the air of Pretoria, Johannesburg and Durban, South Africa(5). Concentration measured in aircraft 350 to 500 m over Tokyo (258 samples) 0.8 ppb, mean(8). The average concentration of 2-methylpentane at street level in London, 1988, was 55 ppb(10). 2-Methylpentane was detected in Edmonton, Alberta, Canada at median concentrations 3.80 and 5.48 ug/cu m in downtown and industrial areas, respectively(11). 2-Methylpentane has been detected in roadway air, airport facility air, and 'near' aircraft air in concentrations of 2.434, 2.01, and 1.2080 ppb, respectively(12). In 1990 2-methylpentane comprised 1.2% of UK volatile emissions based on mass(13). Motorcycle and roadway emissions collected from downtown Cairo, Egypt near the Sheraton Tunnel in June 1997 contained 2-methylpentane/4-methyl-2-pentene at 4.12 and 2.82% by weight, respectively(14). 2-methylpentane was detected with a mean concentration of 9.6 mg/cu m in urban air from Porto Alegre, Brazil, March 1996-April 16, 1997(15). Ethane was detected in Vienna, Austria (1988), Sydney, Australia (1982), Chicago, IL (1989) and Osaka, Japan (1993) in average concentrations of 3.2, 2.6, 2.4 and 3.9 ppbV, respectively(16) 2-Methylpentane was detected at concentrations ranging from 1.3-6.9 ppbV and averaging 3.3 ppbV from samples collected from Ancient Angora, Athens, Greece 4 m above ground between June 9-12 of 1993, May 6-7 and 9-10 and July 7-9, 11 of 1994(16). 2-Methylpentane has been detected in urban air of Bilbao, Spain at an approximate mean concentration of less than 0.4 ppbV(17). An air sample collected on a London street contained 2-methylpentane at 55 ppbV(18). Concentrations of 2-methylpentane measured in a London photochemical plume study (July 12, 1988) averaged 784 and 464 ppbV in two separate flights; concentrations out-of-the-plume ranged from less than 2 to 405 ppbV(18).

INDOOR: A 1995 study at a former gasoline station in California, where high levels of gasoline hydrocarbon vapors had been previously confirmed in the soil, detected 2-methylpentane in indoor air at a level of 6.6 ug/cu m(1). The concentrations of 2-methylpentane in a car and train (n=8) during parallel commuter trips in Goeteborg, Sweden were 17.9 and 2.7 ug/cu m, respectively(2). In an office building, 2-Methylpentane was detected in the renovated area (ug/cu m, days since construction commenced): 2300 at 14 days, 4.9 at 81 days, and 1.4 at 142 days; in the upstairs area (ug/cu m, days since construction commenced;): 670 at 14 days, 780 at 15 days, and 36 at 27 days(3). 2-Methylpentane was detected in the air of 5 buildings in Greece (suburb/rural and downtown locations); the highest concentration detected was approximately 50 ug/cu m(4).

RURAL/REMOTE: Norwegian arctic concentration 0.182 ppb spring, <0.020 ppb summer(1). Four remote sites in northwest North Carolina sampled over 13 months resulted in concentrations of 0.24-0.72 ppb, median; 0.12-2.4 ppb, range for 2-methylpentane(2). 2-Methylpentane was detected at one of four rural sites in the US at a mean level of 0.8 ppb(3). Smokey Mountains, TN (9 samples) 1.0-5.2 ppb(4); Rio Blanco County, CO (5 sites) 1.0-3.0 ppb(5); Rural sites in NW England, <0.6 ppb, mean(6). Detected, not quantified, in a spruce forest in Germany(7). In oil field emissions measured in Tulsa, OK, 2-methylpentane was detected at average concentration of 121.1 ppbC(8). 2-Methylpentane was detected at approximate concentrations of 0.01-0.10 ppbV in the interstitial air of the Arctic snowpack(9). 2-Methylpentane was detected in the atmosphere of the Borden Forest, Canada in 1993 at approximate concentrations of 0.08-0.13 ppb during daytime hours and 0.1-0.15 ppb during nighttime hours(10). Forest hydrocarbon emissions near Baton Rouge Louisiana had background 2-methylpentane levels ranging from 0.5-3.5 ppbV; the study indicated that this chemical was not emitted from the trees analyzed in the study(11).

SOURCE DOMINATED: 2-Methylpentane concentrations at a natural gas facility in Rio Blanco County, CO was 59.4 ppb and at a refinery in Tulsa, OK (2 samples) was 19.0-47.8 ppb(1). 2-Methylpentane was detected, but not quantitated, in ambient roadside air(2) and in the Allegheny Mountain Tunnel on the Pennsylvania Turnpike(3). Emissions from a petroleum refinery, lead smelter (using a heavy oil as fuel), and cast iron factory (using coal as a fuel) were sampled in Cairo, Egypt; 2-methylpentane/4-methyl-2-pentene were measured at 1.59, 0.42, and 0.72% by weight, respectively(4). A study at a former gasoline station in California, where high levels of gasoline hydrocarbon vapors had been previously detected in the soil, detected 2-methylpentane in outdoor air at a level of 5.6 ug/cu m and in groundwater collected under the building (2m) at a concentration of 79000 mg/cu m (5). 2-Methylpentane was detected in air samples collected in June 2004 from a gasoline service station located in Brazil at an average concentration of 492.1 ug/cu m(6).

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).

2-Methylpentane was identified in the emissions of combusted pine wood at 8.6 mg 2-methylpentane per kg of wood burned(1).

Organic substances, including 2-methylpentane, were found in the concentration range of 1-100 ppb in the air of telephone central offices in the USA; indoor concentrations were higher than outside air concentrations(1). Hexane and its isomers showed an alveolar concentration to environmental concentration ratio higher than 0.5(2).

According to the 2006 TSCA Inventory Update Reporting data, the number of persons reasonably likely to be exposed in the industrial manufacturing, processing, and use of 2-methylpentane is 1000 or greater; the data may be greatly underestimated(1).

NIOSH (NOES Survey 1981-1983) has statistically estimated that 533 workers (215 of these were female) are potentially exposed to 2-methylpentane in the USA(1). Occupational exposure to 2-methylpentane may occur through inhalation and dermal contact with this compound at workplaces where 2-methylpentane is produced or used(SRC). Monitoring data indicate that the general population will be exposed to 2-methylpentane in ambient air, especially in areas of high traffic and at filling stations. Exposure via inhalation and dermal contact may also result from the use of glues and other products in which 2-methylpentane is contained as a solvent(SRC).

The average composition of gasoline vapor expsoures was 3.4, 4.9, and 2.1 wt percent for Amoco oil bulk terminal, Amoco oil marine loading, and Shell oil, respectively(1). A survey of a high volume service station in eastern PA, whose site represented a maximum exposure to gasoline vapors found that all 15 personal-long term samples contained 2-methylpentane; the 3 that were quantifiable ranged from 0.1 to 0.3 ppm(2). Air concentrations (95% confidence limits) of 2-methylpentane measured by eight petroleum companies for service station attendants (49 measurements), transport drivers (49 measurements), and outside operators (56 measurements) were 2.01 (1.55-2.47), 1.69 (0.80-2.57), and 0.61 (0.37-0.84) mg/cu m(3), respectively. 2-Methylpentane was detected in the ambient air of a shoe factory in Italy in Nov 1991 at median concentrations of 109 and 416 mg/cu m, and in Feb 1992 at a median concentration of 128 mg/cu m(4).

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).

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.

/GUIDE 128: FLAMMABLE LIQUIDS (NON-POLAR/WATER-IMMISCIBLE)/ Fire or Explosion: HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames. Vapors may form explosive mixtures with air. Vapors may travel to source of ignition and flash back. Most vapors are heavier than air. They will spread along ground and collect in low or confined areas (sewers, basements, tanks). Vapor explosion hazard indoors, outdoors or in sewers. Those substances designated with a "P" may polymerize explosively when heated or involved in a fire. Runoff to sewer may create fire or explosion hazard. Containers may explode when heated. Many liquids are lighter than water. Substances may be transported hot. /Hexanes/

/GUIDE 128: FLAMMABLE LIQUIDS (NON-POLAR/WATER-IMMISCIBLE)/ Health: Inhalation or contact with material may irritate or burn skin and eyes. Fire may produce irritating, corrosive and/or toxic gases. Vapors may cause dizziness or suffocation. Runoff from fire control or dilution water may cause pollution. /Hexanes/

/GUIDE 128: FLAMMABLE LIQUIDS (NON-POLAR/WATER-IMMISCIBLE)/ Public Safety: CALL Emergency Response Telephone Number ... As an immediate precautionary measure, isolate spill or leak area for at least 50 meters (150 feet) in all directions. Keep unauthorized personnel away. Stay upwind. Keep out of low areas. Ventilate closed spaces before entering. /Hexanes/

/GUIDE 128: FLAMMABLE LIQUIDS (NON-POLAR/WATER-IMMISCIBLE)/ Protective Clothing: Wear positive pressure self-contained breathing apparatus (SCBA). Structural firefighters' protective clothing will only provide limited protection. /Hexanes/

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

UN 1208; Hexanes

IMO 3.2; Hexanes

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 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.

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.

Flammable Liquid

UN Hazard Class: 3; UN Pack Group: II