n-Hexane

CAS110-54-3

Molecular formulaC6H14

Molar mass86.18 g/mol

Hazardous

Hazards Summary | n-Hexane is a chemical made from crude oil. Pure n-Hexane is a colorless liquid with a slightly disagreeable odor. It is highly flammable, and its vapors can be explosive. Puren-Hexane is used in laboratories. Most of then-Hexane used in industry is mixed with similar chemicals called solvents. The major use for solvents containing n-Hexane is to extract vegetable oils from crops such as soybeans. These solvents are also used as cleaning agents in the printing, textile, furniture, and shoemaking industries. Certain kinds of special glues used in the roofing and shoe and leather industries also contain n-Hexane. Several consumer products containn-Hexane, such as gasoline, quick-drying glues used in various hobbies, and rubber cement. .

Scientific Grain Officer - Dictionary Editorial Department, revised at:2026-10-19

Toxicity

Body Burden

n-Hexane was detected in 8 of 12 samples of mothers breast milk from the cities of Bayonne NJ, Jersey City NJ, Bridgeville PA and Baton Rouge LA(1). The air expired from humans contained n-hexane in 6.9% of the 387 samples collected from 54 subjects(2). The average n-hexane concentration of 4.7 ng/L was expressed as the geometric mean with upper and lower limits of 13.5 and 1.63 ng/L, respectively(2).

Ecotoxicity Values

USDA APHIS Chemical Effects: collection=usda_chemeffect&query_type=synonym&query='^110-54-3$'

Fate Summary

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), n-hexane, which has a vapor pressure of 153 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase n-hexane 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 24 hours(SRC), calculated from its rate constant of 5.61X10-12 cu cm/molecule-sec at 25 °C(3). n-Hexane does not contain chromophores that absorb at wavelengths >290 nm(4) and, therefore, is not expected to be susceptible to direct photolysis by sunlight(SRC).

Soil Adsorption / Mobility

Using a structure estimation method based on molecular connectivity indices(1), the Koc of n-hexane can be estimated to be 130(SRC). According to a classification scheme(2), this estimated Koc value suggests that n-hexane is expected to have high mobility in soil.

Environmental Biodegradation

AEROBIC: Biodegradation of n-hexane, present at 7% weight as part of a mixture of 13 volatile fuel compounds including methyl tert-butyl ether, was studied in large-scale lysimeter representing depth of a 2.3 m thick sandy unsaturated zone over a gravel aquifer and studied for 70 days. A first-order rate constant of 0.40/day was reported at day 7(1), corresponding to a half-life of 2 days(SRC). The compound was not detected by day-13(1).

Environmental Bioconcentration

An estimated BCF of 170 was calculated in fish for n-hexane(SRC), using a log Kow of 3.90(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is high(SRC), provided the compound is not metabolized by the organism(SRC).

Volatilization from Water / Soil

The Henry's Law constant for n-hexane is estimated as 1.80 atm-cu m/mole(SRC) derived from its vapor pressure, 153 mm Hg(1), and water solubility, 9.5 mg/L(2). This Henry's Law constant indicates that n-hexane 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 2.7 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 3.7 days(SRC). n-Hexane's estimated Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC). The potential for volatilization of n-hexane from dry soil surfaces may exist(SRC) based upon a vapor p...

Environmental Abiotic Degradation

Estimated lifetime under photochemical smog conditions in SE England: 5.9 hr; photooxidation by ultraviolet light in aqueous medium at 50 °C: 50.51% degradation to carbon dioxide after 24 hr.

Environmental Water Concentrations

RAIN/SNOW/FOG: n-Hexane was detected in cloud water at Mitchell State Park, NC at an average concentration of 1.56 ng/mL(1).

Food Survey Values

n-Hexane was identified as a volatile component of roasted filberts(1) and chickpeas(2).

Milk Concentrations

n-Hexane was detected in 8 of 12 samples of mothers breast milk from the cities of Bayonne NJ, Jersey City NJ, Bridgeville, PA and Baton Rouge LA(1).

Ecotoxicity Excerpts

/AQUATIC SPECIES/ Giant kelp (Macrocystis pyrifera): little or no effect on the photosynthetic activity: 10 mg/L.

Plant Concentrations

n-Hexane was identified, not quantified, in the volatile component of kiwi fruit flowers (Actinidia chinensis)(1). The compound was reported, not quantified in the stem of kohlrabi (Brassica oleracea var. gongylodes)(2).

Effluent Concentrations

Data from Sept 2, 1979 identified n-hexane as a vapor emission of the vehicle traffic through the Allegheny Mountain Tunnel of the Pennsylvania Turnpike(1). The exhaust from 67 gasoline fueled vehicles was found to contain n-hexane at an average concentration of 2.0% by weight(2). n-Hexane ranged in concentration from 0.02 to 0.05 ppm from automobile exhaust in California(3). The emission of n-hexane from automobiles inside and outside a roadway tunnel in Los Angeles, CA was measured as 135 mg/L(4). The concentration of n-hexane in cold start emissions ranged from 50-100 mg/start of a 1993 Buick Regal Custom(5). Effects of the 2008 Beijing Olympics and Paralympics control measures on reducing reactive hydrocarbon species saw a reduction of gasoline vehicle exhaust 53-77% and 59-68%, res...

ICSC Environmental Data

The substance is toxic to aquatic organisms.

Natural Pollution Sources

n-Hexane is a constituent in the paraffin fraction of crude oil and natural gas.

Atmospheric Concentrations

RURAL/REMOTE: The respective median, minimum and maximum atmospheric concentrations of n-hexane for 5 rural locations in NC ranged from 0.2 to 7.5, 0.1 to 5.8, and 0.7 to 10.6 ppb, respectively(1). n-Hexane was identified, not quantified, in the atmospheres of downtown Tuscaloosa, AL and a rural site 35 miles away, the Talladega National Forest from December 1976 through 1977(2). The atmospheric concentration of n-hexane at the Jones State Forest in rural TX was 4.1 ppb in 1978(3). The average concentration of n-hexane at a rural site in Northern Berlin, Germany was 0.33 ug/cu m(4). The average n-hexane concentration for samples taken at altitudes of 300 to 2,500 ft over Lake Michigan on Aug 27, 1976 was 0.5 ppb(1). The average n-hexane concentration for samples taken at altitudes of 1,...

Artificial Pollution Sources

n-Hexane's production and use as a solvent, formulation additive, use in low-temperature thermometers, polymerization reaction medium(1,2), and as a component of petroleum and gasoline products(3) may result in its release to the environment through various waste streams(SRC).

Sediment/Soil Concentrations

SOIL: n-Hexane was identified, not quantified, in the soil surrounding an earthen disposal pit in the Duncan Oil Field, NM(1).

Probable Routes of Human Exposure

Workers were exposed to mixt of solvents containing n-hexane in concentrations ranging between 500 and 1000 ppm with higher peaks through various working processes such as glueing in sandal, shoe, belt and furniture mfg, polyethylene laminating, and cleaning tablets in pharmaceutical plant.

Other Environmental Concentrations

n-Hexane was detected at concentrations of 0.34, 0.15, 0.41, 0.12, 0.80, and 0.08 nL/L volatile from corn silage, alfalfa silage, high moisture ground corn, total mixed ration feed, almond hulls, and almond shells, respectively, in a San Joachin Valley, CA survey of volatile organic compounds emitted from dairy silages and other feedstuffs(1).

Environmental Fate / Exposure Summary

n-Hexane's production and use as a solvent, formulation additive, use in low-temperature thermometers, polymerization reaction medium, and as a component of petroleum and gasoline products may result in its release to the environment through various waste streams. n-Hexane is also a component of natural gas and crude oil. If released to air, a vapor pressure of 153 mm Hg at 25 °C indicates n-hexane will exist solely as a vapor in the atmosphere. Vapor-phase n-hexane 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 24 hours. n-Hexane does not contain chromophores that absorb at wavelengths >290 nm and, therefore, is not expected to be susceptible to direct photolysis by sunlight. If r...

Symptoms

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)

Target Organs

Eyes, skin, respiratory system, central nervous system, peripheral nervous system

Toxicity Data

LD50: 28 710 mg/kg (Oral, Rat) (T14) LC50: 48 000 ppm over 4 hours (Inhalation, Mouse) (L174)

Health Effects

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)

Adverse Effects

Neurotoxin - Acute solvent syndrome

Exposure Routes

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

Toxicity Summary

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) CDC-ATSDR Toxicological Profile

Minimum Risk Level

Chronic Inhalation: 0.6 ppm (L134)

RAIS Toxicity Values

Oral Subchronic Chronic Reference Dose Reference: PPRTV Current

Carcinogen Classification

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

Populations at Special Risk

Populations at risk are "glue sniffers" ... where hexane is employed as a glue solvent.

1 or Cancer Risk Level 1E-06

Soil Saturation Concentration (mg/kg): 1.41e+02

Antidote and Emergency Treatment

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 re...

Hazard Quotient Level 3 or Cancer Risk Level 1E-04

Soil Saturation Concentration (mg/kg): 1.41e+02

USGS Health-Based Screening Levels for Evaluating Water-Quality

Reference: Smith, C.D. and Nowell, L.H., 2024. Health-Based Screening Levels for evaluating water-quality data (3rd ed.). DOI:10.5066/F71C1TWP