Hexane (and related aliphatic hydrocarbons)

(Normal hexane, skellysolve B)

CAS 110-54-3





Physical Properties

Colorless liquid

bp 69 °C, mp -95 °C

Slightly soluble in water (0.014 g/100 mL)



Mild gasoline-like odor detectable at 65 to 248 ppm

Vapor Density

3.0 (air = 1.0)


Vapor Pressure

124 mmHg at 20 °C


Flash Point

-21.7 °C


Autoignition Temperature

225 °C


Toxicity Data

LD50 oral (rat)

28,700 mg/kg



500 ppm (1800 mg/m3)



50 ppm

Major Hazards

Highly flammable; chronic exposure may cause neurotoxic effects.


Hexane and related aliphatic hydrocarbons exhibit only slight acute toxicity by all routes of exposure. The liquid may cause irritation upon contact with skin or eyes. Hexane vapor (and the vapor of other volatile hydrocarbons) at high concentrations (>1000 ppm) is a narcotic, and inhalation may result in lightheadedness, giddiness, nausea, and headache. Ingestion of hexane or other hydrocarbons may lead to aspiration of the substance into the lungs, causing pneumonia. Prolonged skin exposure may cause irritation due to the ability of these solvents to remove fats from the skin. Hexane is regarded as a substance with good warning properties.

Chronic exposure to hexane or other aliphatic hydrocarbons may cause central nervous system toxicity. Hexane has not been found to be a carcinogen or reproductive toxin in humans.

Flammability and Explosibility

Hexane is extremely flammable (NFPA rating = 3), and its vapor can travel a considerable distance to an ignition source and "flash back." Hexane vapor forms explosive mixtures with air at concentrations of 1.1 to 7.5 % (by volume). Hydrocarbons of significantly higher molecular weight have correspondingly higher vapor pressures and therefore present a

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