2,2,4-trimethylpentane

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]

H400: Very toxic to aquatic life [Warning Hazardous to the aquatic environment, acute hazard]

H410: Very toxic to aquatic life with long lasting effects [Warning 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 (100%): Highly Flammable liquid and vapor [Danger Flammable liquids]

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

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

H336 (98.8%): May cause drowsiness or dizziness [Warning Specific target organ toxicity, single exposure; Narcotic effects]

H400 (91.8%): Very toxic to aquatic life [Warning Hazardous to the aquatic environment, acute hazard]

H410 (100%): Very toxic to aquatic life with long lasting effects [Warning Hazardous to the aquatic environment, long-term hazard]

Aggregated GHS information provided per 572 reports by companies from 38 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.

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

H400 (100%): Very toxic to aquatic life [Warning Hazardous to the aquatic environment, acute hazard]

Aggregated GHS information provided per 26 reports by companies from 8 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

H224 (100%): Extremely flammable liquid and vapor [Danger Flammable liquids]

H302 (100%): Harmful if swallowed [Warning Acute toxicity, oral]

H335 (100%): May cause respiratory irritation [Warning Specific target organ toxicity, single exposure; Respiratory tract irritation]

P210, P233, P240, P241, P242, P243, P261, P264, P270, P271, P280, P301+P317, P302+P352, P303+P361+P353, P304+P340, P319, P321, P330, P332+P317, P362+P364, P370+P378, P403+P233, P403+P235, P405, and P501 (click each P-code to see the statement)

The GHS information provided by 1 company from 1 notification to the ECHA C&L Inventory.

Fresh air, rest. Artificial respiration may be needed. 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. Do NOT induce vomiting. Refer for medical attention .

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)

General First Aid:

· Call 911 or emergency medical service.

· Ensure that medical personnel are aware of the material(s) involved, take precautions to protect themselves and avoid contamination.

· Move victim to fresh air if it can be done safely.

· Administer oxygen if breathing is difficult.

· If victim is not breathing:

-- DO NOT perform mouth-to-mouth resuscitation; the victim may have ingested or inhaled the substance.

-- If equipped and pulse detected, wash face and mouth, then give artificial respiration using a proper respiratory medical device (bag-valve mask, pocket mask equipped with a one-way valve or other device).

-- If no pulse detected or no respiratory medical device available, provide continuous compressions. Conduct a pulse check every two minutes or monitor for any signs of spontaneous respirations.

· Remove and isolate contaminated clothing and shoes.

· For minor skin contact, avoid spreading material on unaffected skin.

· In case of contact with substance, remove immediately by flushing skin or eyes with running water for at least 20 minutes.

· For severe burns, immediate medical attention is required.

· Effects of exposure (inhalation, ingestion, or skin contact) to substance may be delayed.

· Keep victim calm and warm.

· Keep victim under observation.

· For further assistance, contact your local Poison Control Center.

· Note: Basic Life Support (BLS) and Advanced Life Support (ALS) should be done by trained professionals.

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.

In Canada, an Emergency Response Assistance Plan (ERAP) may be required for this product. Please consult the shipping paper and/or the "ERAP" section.

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 powder, AFFF, foam, carbon dioxide. In case of fire: keep drums, etc., cool by spraying with water. Combat fire from a sheltered position.

· 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.

· Keep unauthorized personnel away.

· Stay upwind, uphill and/or upstream.

· Ventilate closed spaces before entering, but only if properly trained and equipped.

· 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.

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)

Immediate precautionary measure

· Isolate spill or leak area for at least 50 meters (150 feet) in all directions.

· Consider initial downwind evacuation for at least 300 meters (1000 feet).

· 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.

Evacuate danger area! Personal protection: self-contained breathing apparatus. Remove all ignition sources. 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.

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. Separated from strong oxidants. Cool. Keep in a well-ventilated room.

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

· Structural firefighters' protective clothing provides thermal protection but only limited chemical protection.

500.0 [ppm]

200 [ppm]

2200 [ppm]

13000 [ppm]

300.0 [ppm]

300 ppm as TWA.

470 mg/m

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.

No indication can be given about the rate at which a harmful concentration of this substance in the air is reached on evaporation at 20 °C.

The substance is irritating to the eyes, skin and respiratory tract. The substance may cause effects on the kidneys, liver and nervous system. If this liquid is swallowed, aspiration into the lungs may result in chemical pneumonitis.

The substance defats the skin, which may cause dryness or cracking.

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)

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 ventilation, local exhaust or breathing protection.

Protective gloves.

Wear safety goggles.

Do not eat, drink, or smoke during work.

Isooctane appears as a clear colorless liquid with a petroleum-like odor. Less dense than water and insoluble in water. Vapors are heavier than air.

CBI; Gas Vapor; Liquid

Colorless liquid with an odor of gasoline; [HSDB]

COLOURLESS LIQUID WITH CHARACTERISTIC ODOUR.

MOBILE LIQUID

COLORLESS LIQUID

ODOR OF GASOLINE

99.238 °C

99.2 °C @760 [mm Hg]

-107.45 °C

-107.5 °C

10 °F (NFPA, 2010)

4.5 °C (OPEN CUP)

4.5 °C o.c.

PRACTICALLY INSOL IN WATER; SOMEWHAT SOL IN ABS ALC; SOL IN BENZENE, TOLUENE, XYLENE, CHLOROFORM, ETHER, CARBON DISULFIDE, CARBON TETRACHLORIDE, DMF & OILS, EXCEPT CASTOR OIL.

MISCIBLE WITH ACETONE, HEPTANE.

Solubility in water: none

0.69194 @ 20 °C/4 °C

Relative density (water = 1): 0.69

0.692 @ 20°C

3.93 (AIR= 1)

Relative vapor density (air = 1): 3.9

49.3 [mmHg]

40.6 MM HG @ 21 °C

Vapor pressure, kPa at 20 °C: 5.1

40.6 [mm Hg] @21 °C

784 °F (418 °C)

LESS THAN 32 SAYBOLT UNIVERSAL SECONDS

INDEX OF REFRACTION: 1.39157 @ 20 °C/D

ANTIKNOCK OCTANE NUMBER 100; DIPOLE MOMENT: 0

Boiling point

Chemical diffusion

Composition

Compressibility

Critical point

Diamagnetic susceptibility

Dielectric constant

Diffusion

Diffusive flux

Excess enthalpy

Highly flammable. Insoluble in water.

Hydrocarbons, Aliphatic Saturated

Highly Flammable

Saturated aliphatic hydrocarbons, such as ISOOCTANE, 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.

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

Petroleum distillates are central nervous system depressants and cause pulmonary damage. (A600)

2,2,4-Trimethylpentane

Male rat-specific kidney tumors can occur after exposures to a structurally diverse group of substances or their metabolites. This arises from binding to α2u, a low-molecular-weight protein. Examples of these substances include 1,4-dichlorobenzene (and -2,5-dichlorophenol, its metabolite), d-limonene (and d-limonene 2-5-oxide, its metabolite), methyl isobutyl ketone (MIBK), 2,2,4-trimethylpentane, (and 2,4,4-trimethyl-2-pentanol, its metabolite), tertiary butyl alcohol (TBA), ethyl tertiary butyl ether (ETBE) (and TBA, its metabolite), and methyl tert-butyl ether (MTBE) (and TBA, its metabolite). They induce α2u-globulin nephropathy, a mode of action (MoA) noted in a series of studies and publications over recent decades as not being relevant in humans. The nephropathy can lead to kidney tumor formation in male rats.

2,2,4-Trimethylpentane is found in gasoline, which is possibly carcinogenic to humans (Group 2B). (L135)

Petroleum distillates are aspiration hazards and may cause pulmonary damage, central nervous system depression, and cardiac effects such as cardiac arrhythmias. They may also affect the blood, immune system, liver, and kidney. (A600, L1297)

The substance can be absorbed into the body by inhalation and by ingestion.

Oral (L400) ; inhalation (L400) ; dermal (L400)

Confusion. Dizziness. Headache. Nausea. Vomiting.

Dry skin. Redness. Pain.

Redness.

Further see Inhalation.

Petroleum distillate poisoning may cause nausea, vomiting, cough, pulmonary irritation progressing to pulmonary edema, bloody sputum, and bronchial pneumonia. At high amounts, central nervous system depression may also occur, with symptoms such as weakness, dizziness, slow and shallow respiration, unconsciousness, and convulsions. Petroleum distillates are also irritating to the skin. (A594)

Neurotoxin - Acute solvent syndrome

Occupational hepatotoxin - Secondary hepatotoxins: the potential for toxic effect in the occupational setting is based on cases of poisoning by human ingestion or animal experimentation.

Treatment is mainly symptomatic and supportive. Gastric lavage, emesis, and the administration of activated charcoal should be avoided, as vomiting increases the risk of aspiration. (A600)

RABBITS WERE EXPOSED TO 2500 OR 5000 PPM CARBON MONOXIDE, WITH OR WITHOUT 5000 PPM OCTANE, OR ISO-OCTANE, OR TO AUTOMOBILE EXHAUST FUMES. THE HYDROCARBONS ENHANCED THE CARBON MONOXIDE INDUCED HYPOTENSION & BRADYCARDIA, BUT HASTENED THE RECOVERY FROM THE CARBON MONOXIDE INDUCED ELECTROCARDIOGRAPHIC MODIFICATIONS.

A DESCRIPTION IS GIVEN OF A SERIOUS HAND INJURY WHICH RESULTED FROM THE UNPACKING OF SILICON DIOXIDE FILLED HIGH-PERFORMANCE LIQUID CHROMATOGRAPHIC COLUMN BY PUMPING ISOOCTANE THROUGH THE COLUMN. A MIXTURE OF SILICON DIOXIDE & ISOOCTANE WAS SUDDENLY DISCHARGED SO VIOLENTLY THAT SOME ISOOCTANE PENETRATED THE SKIN, CAUSING NECROSIS WHICH REQUIRED SURGERY.

The abilities of unleaded gasoline and 2,2,4-trimethylpentane which comprises about 10% of unleaded gasoline to induce gene locus mutation and sister chromatid exchange in a human lymphoblast system were investigated. TK6 human lymphoblastoid cells were used. The cytotoxic effects of medium saturated with these agents were first determined by monitoring cell growth following treatment. For cell exposures, a hydrocarbon saturated medium was mixed in different ratios with normal medium containing the cells. Exposures were for 3 hours. For unleaded gasoline, ratios were 1:7 or 1:3 (saturated/normal); for 2,2,4-trimethylpentane, 1:1 or no dilution concentrations were used. Incubations were performed with and without S9. Benzo(a)pyrene was used as a positive control and to test the bioactivating ability of S9 in the presence of the treatment agents. Unleaded gasoline in a 1:1 ratio dissolved TK6 cells. A reduction to 1:3 increased cell survival to approximately 70%. Greater than 60% of cells survived treatment in the 2,2,4-trimethylpentane saturated medium. Neither unleaded gasoline at its maximum tolerated concentration, nor 2,2,4-trimethylpentane at its limit of solubility, induced mutation at the thymidine kinase locus. Negative results were seen both in the presence and absence of the rat liver homogenate metabolizing system. Sister chromatid analyses were also negative for both agents. The expected frequency of mutation was observed with benzo(a)pyrene in the presence of the bioactivating system indicating that no inhibition of metabolism was taking place. The authors conclude that the carcinogenicity and nephrotoxicity of these agents observed in vivo do not correlate with any marked genotoxicity in vitro.

... THE ISOOCTANES ... APPEAR TO CAUSE PULMONARY LESIONS IF ASPIRATED INTO LUNG OF RATS. /ISOOCTANES/

THE PATHOLOGICAL LUNG FINDINGS IN RABBITS INJECTED IM WITH CYCLOHEXANE, N-HEXANE OR ISO-OCTANE TEST GROUPS INCLUDE HEMORRHAGE, EDEMA & TISSUE WITH POLYMORPHONUCLEAR LEUKOCYTIC REACTIONS, SUCH AS ANGITIS, INTERSTITIAL PNEUMONITIS, ABSCESS FORMATION, THROMBOSIS & FIBROSIS.

ISO-OCTANE WAS HIGHLY IRRITATING TO MICE AFTER 1000 PPM EXPOSURE FOR 5 MINUTES. RESPIRATORY ARREST OCCURRED IN THE EXPIRATORY PHASE DURING PROLONGED EXPIRATION.

The acute toxicity of isooctane has been reported ... in mice. Isooctane at 16,000 ppm causes respiratory arrest in 25% of the mice generally within 6 min, while concentrations of 32,000 ppm cause arrest in all animals after 3-4 min. The concentration of isooctane necessary to induce /CNS depression/ has not been determined; however, ... /it was/ found that exposure of mice to 8000 ppm for 5 min does not cause /CNS depression/. The /CNS depressant/ effect of isooctane probably occurs between 8000-10,000 ppm ...

For more Non-Human Toxicity Excerpts (Complete) data for ISO-OCTANE (9 total), please visit the HSDB record page.

Iso-octane (2,2,4-trimethylpentane) is a volatile constituent of petroleum products and natural gas. Although the compound occurs naturally, it is principally released to the environment via the manufacture, use and disposal of products associated with the petroleum and gasoline industry. Photolysis and hydrolysis of iso-octane are not expected to be important environmental fate processes in any environmental media. Based upon limited data, biodegradation of the compound may occur slowly in soil and water, but probably only where the compound has been preexposed. Volatilization of the compound from water and soil surfaces may be the most important fate process. The volatilization half-life of iso-octane from a model river 1 meter deep flowing at 1 m/sec with a wind speed of 3 m/sec has been estimated to be 3.1 hrs. The Koc value of iso-octane indicates that it will not be very mobile in soil and may partition from the water column to suspended solids and sediments in water. The estimated bioconcentration factor indicates that bioconcentration may be important in aquatic organisms. The most important fate process for this compound in air may be its reaction with photochemically produced hydroxyl radicals. This reaction has an estimated half-life of 4.4 days. The most probable route of human exposure to iso-octane is by inhalation. Both general population and occupational exposure to this compound are likely. (SRC)

Iso-octane is naturally found in crude petroleum(1) and in small amounts in natural gas(2).

JP-4 (JET FUEL) SAMPLES CONTAIN HYDROCARBONS, INCLUDING ISO-OCTANE.

Since iso-octane is a constituent of petroleum and gasoline, it is released to the environment by the petroleum industries during refining processes and during the use of gasoline(2). Automotive exhaust and automotive evaporative emissions are most important sources of iso-octane in the atmosphere(1,4-7). Products, such as polyethylene pipes used for distribution of drinking water, can release this compound in water and the atmosphere(9). Hazardous wastes sites(3), landfills(3,8) and emissions from wood combustion(7) also release iso-octane into the environment.

TERRESTRIAL FATE: Photolysis and hydrolysis of iso-octane are not expected to important in soil(2,6). Although iso-octane may undergo slow biodegradation in soil(5), volatilization from dry and wet soil surfaces is expected to be more important fate process. The vapor pressure of 49.3 mm Hg(3) and a value of 3.01 atm cu-m/mole for Henry's Law constant(4) indicates high volatility from dry and moist soil surface. In subsurface soil, adsorption of iso-octane is expected to be important as indicated by average log Koc value of 4.35 in three sediments(1) and an estimated log Koc value of 3.43 in soil(2).

AQUATIC FATE: The hydrolysis of iso-octane in water is not expected to be important because the compound does not contain any hydrolyzable group(2). The photolysis of the compound in water is also expected to be unimportant because iso-octane is transparent to wavelengths available in sunlight(5). Although slow biodegradation may occur in aquatic medium(4), volatilization from water is expected to be the dominant process as indicated by the value 3.01 atm-cu m/mole for Henry's law constant(3). The average log Koc value of 4.35 in sediments(1) indicate that most of the compound may remain adsorbed to sediment and suspended solids in aquatic medium. A log bioconcentration factor of 2.57 estimated from a regression equation based on water solubility(2) indicates that bioconcentration in aquatic organisms may be important.

ATMOSPHERIC FATE: The rate constant for the reaction of iso-octane with atomic oxygen (3P) is 5.5X10+10 cu cm/mol-sec(3). Based on this rate constant and the concentration of atomic oxygen of 2.5X10+4 molecules/cu cm in a typical atmosphere(4), this reaction may not be important in the atmosphere. The gas-phase reactions of alkanes with ozone and nitrate radicals are of negligible importance as atmospheric loss processes(1). The rate constant for the reaction of iso-octane with OH radicals at 25 °C is given as 3.66-3.68X10-12 cu cm/molecule-sec(1,2). Based on an average 24-hr atmospheric OH radical concentration of 5X10+5 molecules/cu cm(5), the half-live of iso-octane due to this reaction is 4.4 days.

BRANCHED OCTANES ... 2,2,4-TRIMETHYLPENTANE ... USED AS THE SOLE CARBON SOURCES BY A VARIETY OF MICROORGANISMS, SUCH AS PSEUDOMONAS FLUORESCENS, CORYNEBACTERIUM, & P. OLEOVORANS.

When a well water (previously contaminated by gasoline spill, but contained no detectable gasoline at the time of the experiment) with added iso-octane to a concentration of 48 mg/L was incubated in the dark at 13 degrees C, the natural flora in the groundwater biodegraded 13% of the compound in 8 days. Therefore, it is likely that iso-octane may undergo slow biodegradation with microorganisms acclimated to this compound.

Alkanes do not contain any hydrolyzable group and are generally resistant to hydrolysis(1). Therefore, hydrolysis of iso-octane in water and soil is not expected to be important. The compound is transparent to tropospheric sunlight(2) indicating that direct photolysis in ambient water and soil may not be important. The rate constants for the gas phase reaction of iso-octane with oxygen atoms (3P) and hydroxyl radicals are 5.5X10+10 cu cm/mol-sec(5) and 3.66-3.68X10-12 cu cm/molecule-sec(3-4), respectively. Based on typical 24-hr average atmospheric atomic oxygen concentrations of 2.5X10+4 molecules/cu cm(6) and OH radical concentration of 5X10+5 radicals/cu cm(7), the reaction with atomic oxygen can be estimated to be unimportant and the half-life for reaction with OH radicals can be estimated to be 4.4 days.

The rate constant for the reaction of OH radicals with iso-octane in aqueous solution is 6.023X10+9/M-sec(1). If it is assumed that the concentration of OH radicals in a typical natural eutrophic water is 3X10-17 M(2), the half-life for the oxidation of iso-octane by photochemically produced OH radicals in water is expected to be 44 days(SRC).

Calculated half-life time in water at 25 °C and 1 m depth based on evaporation: 5.55 hr; evaporation rate: 0.124 m/hr.

Based upon a water solubility of 2.44 mg/L at 25 °C(1), the log bioconcentration factor for iso-octane has been estimated to be 2.57 from a regression equation(2). This value indicates bioconcentration may be important in aquatic organism(SRC).

The adsorption of several hydrocarbons including iso-octane in five types of soil was studied by measuring the retention volumes(1). Hydrocarbon retention by dry soils increased with molecular weight and unsaturation and decreased with branching. The retention volume of iso-octane was found to be high, but the authors did not provide any Koc values. The log Koc for iso-octane in soil has been estimated to be 3.43 from the water solubility of the compound(4) and a regression equation(2). The average log Koc for this compound in sediments from a salt marsh, a pond and a river was 4.35. Therefore, iso-octane is expected to generally remain strongly adsorbed to soil and sediments(5,SRC).

Based on water and vapor phase mass transfer coefficients, the volatilization half-life of iso-octane at 25 °C from a still body of water at a depth of 1 m was estimated to be 5.6 hrs(1). Using more realistic winding blowing conditions, the evaporation half-life of the compound from a model river 1 meter deep, flowing at 1 m/sec with a wind speed of 3 m/sec was estimated to be 3.1 hrs(2). However, neither estimation method considers the effect of adsorption on the rate of volatility. Using EXAMS model which considers various input parameters including the effect of adsorption, the volatilization half-life of iso-octane from a model pond has been estimated to be 15 days(3,SRC).

GROUNDWATER: Iso-octane was detected in one on-site and one off-site well water sample from a waste site of a non-lubricating automotive fluids production plant in Michigan at concentration of 0.005 mg/L and 0.008 mg/L, respectively(1).

Iso-octane (2,2,4-trimethylpentane) is a volatile constituent of petroleum products and natural gas. Although the compound occurs naturally, it is principally released to the environment via the manufacture, use and disposal of products associated with the petroleum and gasoline industry. Photolysis and hydrolysis of iso-octane are not expected to be important environmental fate processes in any environmental media. Based upon limited data, biodegradation of the compound may occur slowly in soil and water, but probably only where the compound has been preexposed. Volatilization of the compound from water and soil surfaces may be the most important fate process. The volatilization half-life of iso-octane from a model river 1 meter deep flowing at 1 m/sec with a wind speed of 3 m/sec has been estimated to be 3.1 hrs. The Koc value of iso-octane indicates that it will not be very mobile in soil and may partition from the water column to suspended solids and sediments in water. The estimated bioconcentration factor indicates that bioconcentration may be important in aquatic organisms. The most important fate process for this compound in air may be its reaction with photochemically produced hydroxyl radicals. This reaction has an estimated half-life of 4.4 days. The most probable route of human exposure to iso-octane is by inhalation. Both general population and occupational exposure to this compound are likely. (SRC)

Iso-octane is naturally found in crude petroleum(1) and in small amounts in natural gas(2).

JP-4 (JET FUEL) SAMPLES CONTAIN HYDROCARBONS, INCLUDING ISO-OCTANE.

Since iso-octane is a constituent of petroleum and gasoline, it is released to the environment by the petroleum industries during refining processes and during the use of gasoline(2). Automotive exhaust and automotive evaporative emissions are most important sources of iso-octane in the atmosphere(1,4-7). Products, such as polyethylene pipes used for distribution of drinking water, can release this compound in water and the atmosphere(9). Hazardous wastes sites(3), landfills(3,8) and emissions from wood combustion(7) also release iso-octane into the environment.

TERRESTRIAL FATE: Photolysis and hydrolysis of iso-octane are not expected to important in soil(2,6). Although iso-octane may undergo slow biodegradation in soil(5), volatilization from dry and wet soil surfaces is expected to be more important fate process. The vapor pressure of 49.3 mm Hg(3) and a value of 3.01 atm cu-m/mole for Henry's Law constant(4) indicates high volatility from dry and moist soil surface. In subsurface soil, adsorption of iso-octane is expected to be important as indicated by average log Koc value of 4.35 in three sediments(1) and an estimated log Koc value of 3.43 in soil(2).

AQUATIC FATE: The hydrolysis of iso-octane in water is not expected to be important because the compound does not contain any hydrolyzable group(2). The photolysis of the compound in water is also expected to be unimportant because iso-octane is transparent to wavelengths available in sunlight(5). Although slow biodegradation may occur in aquatic medium(4), volatilization from water is expected to be the dominant process as indicated by the value 3.01 atm-cu m/mole for Henry's law constant(3). The average log Koc value of 4.35 in sediments(1) indicate that most of the compound may remain adsorbed to sediment and suspended solids in aquatic medium. A log bioconcentration factor of 2.57 estimated from a regression equation based on water solubility(2) indicates that bioconcentration in aquatic organisms may be important.

ATMOSPHERIC FATE: The rate constant for the reaction of iso-octane with atomic oxygen (3P) is 5.5X10+10 cu cm/mol-sec(3). Based on this rate constant and the concentration of atomic oxygen of 2.5X10+4 molecules/cu cm in a typical atmosphere(4), this reaction may not be important in the atmosphere. The gas-phase reactions of alkanes with ozone and nitrate radicals are of negligible importance as atmospheric loss processes(1). The rate constant for the reaction of iso-octane with OH radicals at 25 °C is given as 3.66-3.68X10-12 cu cm/molecule-sec(1,2). Based on an average 24-hr atmospheric OH radical concentration of 5X10+5 molecules/cu cm(5), the half-live of iso-octane due to this reaction is 4.4 days.

BRANCHED OCTANES ... 2,2,4-TRIMETHYLPENTANE ... USED AS THE SOLE CARBON SOURCES BY A VARIETY OF MICROORGANISMS, SUCH AS PSEUDOMONAS FLUORESCENS, CORYNEBACTERIUM, & P. OLEOVORANS.

When a well water (previously contaminated by gasoline spill, but contained no detectable gasoline at the time of the experiment) with added iso-octane to a concentration of 48 mg/L was incubated in the dark at 13 degrees C, the natural flora in the groundwater biodegraded 13% of the compound in 8 days. Therefore, it is likely that iso-octane may undergo slow biodegradation with microorganisms acclimated to this compound.

Alkanes do not contain any hydrolyzable group and are generally resistant to hydrolysis(1). Therefore, hydrolysis of iso-octane in water and soil is not expected to be important. The compound is transparent to tropospheric sunlight(2) indicating that direct photolysis in ambient water and soil may not be important. The rate constants for the gas phase reaction of iso-octane with oxygen atoms (3P) and hydroxyl radicals are 5.5X10+10 cu cm/mol-sec(5) and 3.66-3.68X10-12 cu cm/molecule-sec(3-4), respectively. Based on typical 24-hr average atmospheric atomic oxygen concentrations of 2.5X10+4 molecules/cu cm(6) and OH radical concentration of 5X10+5 radicals/cu cm(7), the reaction with atomic oxygen can be estimated to be unimportant and the half-life for reaction with OH radicals can be estimated to be 4.4 days.

The rate constant for the reaction of OH radicals with iso-octane in aqueous solution is 6.023X10+9/M-sec(1). If it is assumed that the concentration of OH radicals in a typical natural eutrophic water is 3X10-17 M(2), the half-life for the oxidation of iso-octane by photochemically produced OH radicals in water is expected to be 44 days(SRC).

Calculated half-life time in water at 25 °C and 1 m depth based on evaporation: 5.55 hr; evaporation rate: 0.124 m/hr.

Based upon a water solubility of 2.44 mg/L at 25 °C(1), the log bioconcentration factor for iso-octane has been estimated to be 2.57 from a regression equation(2). This value indicates bioconcentration may be important in aquatic organism(SRC).

The adsorption of several hydrocarbons including iso-octane in five types of soil was studied by measuring the retention volumes(1). Hydrocarbon retention by dry soils increased with molecular weight and unsaturation and decreased with branching. The retention volume of iso-octane was found to be high, but the authors did not provide any Koc values. The log Koc for iso-octane in soil has been estimated to be 3.43 from the water solubility of the compound(4) and a regression equation(2). The average log Koc for this compound in sediments from a salt marsh, a pond and a river was 4.35. Therefore, iso-octane is expected to generally remain strongly adsorbed to soil and sediments(5,SRC).

Based on water and vapor phase mass transfer coefficients, the volatilization half-life of iso-octane at 25 °C from a still body of water at a depth of 1 m was estimated to be 5.6 hrs(1). Using more realistic winding blowing conditions, the evaporation half-life of the compound from a model river 1 meter deep, flowing at 1 m/sec with a wind speed of 3 m/sec was estimated to be 3.1 hrs(2). However, neither estimation method considers the effect of adsorption on the rate of volatility. Using EXAMS model which considers various input parameters including the effect of adsorption, the volatilization half-life of iso-octane from a model pond has been estimated to be 15 days(3,SRC).

GROUNDWATER: Iso-octane was detected in one on-site and one off-site well water sample from a waste site of a non-lubricating automotive fluids production plant in Michigan at concentration of 0.005 mg/L and 0.008 mg/L, respectively(1).

The average exhaust from 67 gasoline fueled vehicles driven through an Australian urban driving cycle on a chassis dynamometer contained 1% (w/w) iso-octane of the total non-methane hydrocarbon emitted(3). The average emission of iso-octane from 46 in-use emission-controlled U.S. passenger cars made between 1975-1982 was 2.4% of the total emission (both exhaust and evaporative) under federal test procedure (FTP) driving cycle(2). On the average, 0.25% of the total non-methane hydrocarbon emitted from a wood combustion stack was due to iso-octane(4). Iso-octane has been detected in emitted gases from waste and landfill sites(1,5).

URBAN/SUBURBAN: Iso-octane has been qualitatively detected in the ambient air of many cities around the world including air in Pullman, WA(4). Pretoria, South Africa(3), Johannesburg, South Africa(3), Durban, South Africa(3), Zurich, Switzerland(2) and Leningrad, USSR(1).

URBAN/SUBURBAN: The concentration range of iso-octane in Los Angeles air in 1981 was 3-15 ppb(1). The average and maximum concentration of this compound in Houston, TX air obtained from 679 sampling points were 6 and 101 ppbC, respectively in 1977(3). In Houston, TX, the level of iso-octane ranged from none detected to 416.3 ppbC in Sept. 1983 and 39.1 to 146.8 ppbC in Jan. 1984(2). The background concentration of iso-octane in Janesville, WI air in 1978 was <0.5 ug/cu m, but the concns in atmospheric plume at distances of 10, 15 and 40 miles above Janesville were 1.5, 2.5 and 2.0 ug/cu m, respectively(4). The concn level of iso-octane in Tulsa, OK air in 1978 ranged 2.1-8.5% of the total hydrocarbon, although its composition was 17.1% in the air over a petroleum refinery(5).

URBAN/SUBURBAN: The median and max concn of iso-octane in 39 U.S. cities during 1984-1986 were 6.8 and 106 ppbC(1). The ground level concn of iso-octane on a fall day in 1968 in the Los Angeles Basin was 1.1-10.2 ppb, while the concn 1,500 ft above ground was 18.9 ppb(2). The concn of the compound in urban plumes over Lake Michigan (in the vicinity of Chicago and Milwaukee) in 1976 was 6.8-10.0 ppb(3). The average concn over Tokyo, Japan in 1980 was 0.2 ppb(4).

SOURCE DOMINATED: The average concn of iso-octane inside Lincoln Tunnel was 56.6 ppbC in 1982 compared to 275.3 ppbC in 1970(1). This 5-fold decrease in concn was attributed to the use of catalyst-equipped vehicles(1). The amount of this compound detected along U.S. Highway 70 near Raleigh, NC amounted to 1.07-1.48% of the total non-methane hydrocarbon concn(3). The in-vehicle concn of iso-octane in two four-door sedans averaged 21.1 ug/cu m in urban, 12.0 ug/cu m in interstate and 2.4 ug/cu m in rural areas for these driving routes. The corresponding concns along the sidewalks were 3.8 ug/cu m 1.6 and 0.5 ug/cu m(2).

RURAL/REMOTE: The average concentration of iso-octane in two ground level air samples collected in an orange grove near Dunedin, FL in 1976 was 1.3 ppbC(1). The concn of the compound at Jones State Forest, 38 miles north of Houston, TX in 1978 ranged from 0.3 to 16.7 ppbC(2). The median iso-octane concn in four remote sites in Northwestern North Carolina in 1981-1982 was 0.2 ppbC(3). The compound constituted 0.5% of the total hydrocarbon composition in Smoky Mountain air in 1978(2).

Iso-octane has been detected in the volatile components of Chickpea (Cicer arietinum L)(1).

Unspecified trimethylpentane isomers (probably a mixture) were detected at a concn 0.2 ng/g (wet wt.) in oysters and 1.3 ng/g (wet wt) in clams from Lake Pontchartrain, LA(1).

Iso-octane was detected at a concentration 0.25 mg/l in water when 10 gms of sliced polyethylene pipes used for distribution of potable water was allowed to soak in a liter of mineral water for 48 hrs(1).

The most probable route of human expsoure to iso-octane is by inhalation as indicated by the monitoring data in the gasoline industry(1-3). The detection of the compound in the expired air of "normal" humans (not occupationally exposed)(4) indicates inhalation exposure to general population may be important(SRC).

The occupational exposures of truck drivers and terminal loading operators to gasoline vapors containing iso-octane were studied(1). The mean air concns of iso-octane for service station attendants, transport drivers and outside operators in petroleum industry were 0.670 mg/cu m, 1.495 mg/cu m and 0.824 4 mg/cu m, respectively(2). The concn of iso-octane in the personal air of a high volume service station attendant was 0.2 ppm(3).

Iso-octane was detected in the expired air of 29.7% of selected normal people not occupationally exposed to the compound(1). The geometric mean concentration of iso-octane in the expired air of this general population was 0.604 ng/l(1).

/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.

/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.

/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.

/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.

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

UN 1262; Octanes

IMO 3.2; Octanes

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

Symbol: F, Xn, N; R: 11-38-50/53-65-67; S: (2)-9-16-29-33-60-61-62; Note: C

UN Hazard Class: 3; UN Pack Group: II