99% Purity n- Hexane CAS 110-54-3

​CAS Number:​​ 110-54-3

​Molecular Formula:​​ C₆H₁₄

​Molecular Weight:​​ 86.18 g/mol

​Structural Formula:​​ CH₃(CH₂)₄CH₃

​IUPAC Name:​​ Hexane

​Synonyms:​​

n-Hexane

Dipropyl

Hexyl hydride

(Commercial "Hexane" is often a mixture of hexane isomers and other hydrocarbons

​Physical State:​​ Clear, colorless, highly volatile liquid.

​Odor:​​ Mild, gasoline-like odor.

​Boiling Point:​​ 68.7 °C (155.7 °F)

​Melting Point:​​ -95.3 °C (-139.5 °F)

​Density:​​ 0.659 g/mL at 25 °C

​Vapor Pressure:​​ 124 mmHg at 20 °C (high volatility)

​Flash Point:​​ -23 °C (-9 °F) – ​Highly Flammable.

​Auto-Ignition Temperature:​​ ~225 °C (437 °F)

​Solubility:​​ Immiscible with water. Miscible with alcohol, acetone, chloroform, and most other organic solvents. Excellent solvent for many non-polar compounds (oils, fats, waxes, some polymers).

​Stability:​​ Stable under normal conditions. Highly flammable; vapors can form explosive mixtures with air. Incompatible with strong oxidizing agents. May accumulate static charge.

Toxicology (Primary Concern):​​ n-Hexane is notable for its ​chronic neurotoxicity, which is not shared by most other alkane isomers.

​Metabolism:​​ It is metabolized in the body to 2,5-hexanedione, the primary toxicant.

Mechanism:​​ 2,5-Hexanedione reacts with neurofilament proteins, forming cross-links that disrupt axonal transport in peripheral nerves, leading to degeneration. This results in a sensorimotor ​peripheral neuropathy, characterized by numbness, tingling, and muscle weakness in the extremities, potentially progressing to paralysis.

Acute Effects:​​ Inhalation can cause dizziness, nausea, headache, and respiratory irritation. High concentrations can lead to CNS depression and unconsciousness. Skin contact causes defatting and dermatitis.

Occupational Exposure:​​ Chronic, low-level exposure in industrial settings (e.g., shoe manufacturing, furniture finishing, textile gluing) is linked to "hexane neuropathy."

​Environmental Fate:​​ Volatilizes readily into the atmosphere, where it reacts with photochemically produced hydroxyl radicals. It is not considered persistent or bioaccumulative.

​Natural Occurrence:​​ Not biosynthesized by living organisms in significant quantities. Trace amounts can be found in natural gas, crude oil, and some plant volatiles.

​Industrial Production/Origin:​​ n-Hexane is not "biosynthesized" but is derived exclusively from ​petroleum refining.

1.It is obtained from the light gasoline fraction of crude oil during fractional distillation.

2.The mixed stream of C6 isomers (hexanes) is further processed via ​catalytic isomerization​ and ​selective fractionation​ to increase the concentration of the linear n-hexane isomer for commercial use. High-purity n-hexane (often >95%) is produced for specific applications.

​Q1: What is the main safety concern when handling n-hexane?​​

A1: The two primary hazards are its ​extreme flammability​ (low flash point) and its ​chronic neurotoxicity​ from inhalation exposure. Proper ventilation (preferably engineered controls like local exhaust), protective equipment (gloves, respirators where needed), and strict hygiene practices are mandatory.

​Q2: How is n-hexane different from "commercial hexane"?​​

A2: ​n-Hexane​ refers specifically to the straight-chain isomer. ​Commercial or Laboratory-Grade Hexane​ is typically a mixture containing n-hexane along with other C6 isomers (e.g., methylcyclopentane, 2-methylpentane, 3-methylpentane). The neurotoxic effect is primarily associated with n-hexane, though other isomers can have similar acute hazards.

​Q3: What are the occupational exposure limits for n-hexane?​​

A3: Limits vary by country. Key examples:

​OSHA PEL (USA):​​ Time-Weighted Average (TWA) of 500 ppm (1800 mg/m³).

​NIOSH REL (USA):​​ Recommended TWA of 50 ppm (180 mg/m³) to prevent neuropathy.

​ACGIH TLV (Global):​​ TWA of 20 ppm.

​Q4: Are there safer alternatives to n-hexane?​​

A4: Yes, depending on the application. ​Heptane​ is often a less toxic (though still flammable) alternative with a higher boiling point. ​Cyclohexane​ or ​isohexane​ mixtures may be used, though toxicity profiles differ. For extractions, supercritical CO₂ is a non-flammable, non-toxic alternative, though with higher capital cost.

​Q5: How should n-hexane be stored and disposed of?​​

A5: Store in a cool, well-ventilated area away from ignition sources, heat, and oxidizers. Use approved flammable liquid cabinets. Containers must be grounded to prevent static discharge. Dispose as hazardous waste through licensed handlers; never pour down the drain or into soil.

​Q6: What are the signs of overexposure?​​

A6: ​Acute:​​ Dizziness, giddiness, nausea, headache. ​Chronic:​​ Gradual onset of numbness, tingling ("pins and needles"), and weakness in the hands and feet (stocking-glove neuropathy). Muscle weakness and vision problems may follow.

​Q7: What purity grades are available?​​

A7: Common grades include:

​      Technical Grade (~60% n-hexane):​​ For industrial applications.

​      Commercial Grade (~85% n-hexane):​​ For general use.

​      Pure or Reagent Grade (>95% n-hexane):​​ For laboratories and critical applications.

​      HPLC/GC Grade (>99%):​​ For chromatography, with low UV absorbance.

​Q8: Is it regulated?​​

A8: Yes. It is regulated as a ​hazardous substance​ for transportation, workplace safety (OSHA, others), and environmental release. In the workplace, air monitoring, medical surveillance for exposed workers, and proper hazard communication (GHS labeling, SDS) are required.