n-Hexane
The only common alkane that damages nerves, and it does so because of a metabolite that only a straight six-carbon chain can form. Its branched isomers are harmless, which is precisely why hexane grades are sold on n-hexane content.
Molecular Structure
What is n-Hexane?
n-Hexane is a straight six-carbon alkane: non-polar, volatile, and an excellent solvent for fats, oils, waxes and hydrocarbon polymers. It is essentially insoluble in water and leaves no residue, which is why it dominates edible oil extraction and appears throughout adhesive and polymerisation chemistry.
It is also a peripheral neurotoxin, and uniquely so among the common alkanes. The body oxidises it to 2,5-hexanedione, a diketone that reacts with lysine residues in the neurofilament proteins that give nerve axons their structure, cross-linking them and causing the axon to swell and fail. The result is a slowly progressing loss of sensation and strength beginning in the hands and feet.
Only the straight chain does this. 2-Methylpentane and 3-methylpentane cannot form a 2,5-diketone, so they are not neurotoxic, and that fact governs the market. Commercial hexane runs from around 65% n-hexane in general grades to above 95% where the solvency is needed, and isohexane blends exist specifically as lower-hazard substitutes.
MEK and, to a lesser extent, acetone markedly increase hexane's neurotoxicity by inducing the enzyme that produces the harmful metabolite. Neuropathy has been documented at hexane concentrations that would not have caused it alone. Any operation using hexane alongside ketone solvents must be assessed on the combination.
Quick Reference
Key Physical & Chemical Properties
Structure & Bonding
A straight chain of six carbons with no functional group at all. That simplicity is the source of both its properties — clean non-polar solvency with no residue — and its hazard, because only an unbranched six-carbon chain can be metabolised to the diketone that damages nerves.
Skeletal structure — unbranched six-carbon alkane
Structural Identity
- IUPAC NameHexane
- Common namesn-Hexane, normal hexane
- Molecular FormulaC₆H₁₄
- Molecular Weight86.18 g/mol
- StructureUnbranched — the isomers behave differently
- Toxic metabolite2,5-Hexanedione
- Isomers2- and 3-methylpentane are not neurotoxic
- Potentiated byMEK and, less strongly, acetone
- Made fromNaphtha and NGL fractionation
- CAS Number110-54-3
- InChI KeyVLKZOEOYAKHREP-UHFFFAOYSA-N
Product Specifications
Chelora supplies n-Hexane in standard and custom grades. Contact us for specification sheets tailored to your process.
| Chemical name | n-Hexane |
|---|---|
| CAS Number | 110-54-3 |
| Molecular formula | C₆H₁₄ |
| Molecular weight | 86.18 g/mol |
| n-Hexane content | 65 – 99%, declared per grade |
| Total paraffins (min) | ≥ 99.0 wt% |
| Benzene (max) | ≤ 100 ppm wt technical; ≤ 5 ppm food and pharma grade |
| Total aromatics (max) | ≤ 0.10 wt% |
| Distillation range | 66 – 70 °C for high n-hexane grades |
| Specific gravity | 0.655 – 0.665 at 20/20 °C |
| Colour (Saybolt, min) | ≥ +30 |
| Non-volatile residue (max) | ≤ 5 ppm wt |
| Sulphur (max) | ≤ 1.0 ppm wt |
| Doctor test | Negative |
| Acidity | Neutral |
| Odour | Characteristic, non-residual |
| Flash point | −22 °C (closed cup) |
| Autoignition temperature | 225 °C |
| Flammable limits | 1.1 – 7.5% v/v in air |
| Transport classification | UN 1208, Class 3, PG II |
Downstream Applications & Derivatives
Key derivative chains and industrial uses of n-Hexane.
Edible Oil Extraction
The largest single use worldwide. Soybean, rapeseed, sunflower and rice bran oil are extracted with hexane, which is then recovered and the residual level in the oil controlled by regulation.
Adhesives
Solvent for rubber and contact adhesives in footwear, leather goods and laminating — historically the sector where hexane neuropathy was first recognised.
Polymerisation Solvent
Diluent and slurry medium in polyolefin manufacture and catalyst preparation, where a clean, dry, non-reactive hydrocarbon is required.
Rubber Processing
Rubber cement, tyre repair compounds and crumb rubber processing, where hexane dissolves the elastomer without attacking it chemically.
Laboratory & Chromatography
A standard mobile phase component in normal-phase chromatography and a general extraction solvent in analytical and pharmaceutical work.
Cleaning & Degreasing
Precision degreasing where a fast-evaporating, residue-free non-polar solvent is needed and the exposure can be properly controlled.
Why source n-Hexane through Chelora Petrochem?
Verified Origin
Full origin certification and asset-backed supply chain documentation — no grey-market supply.
Grade Flexibility
Technical, food and pharmaceutical grades supplied across the n-hexane content range, plus isohexane where a lower-hazard substitute is viable. We certify n-hexane content and benzene on every lot.
Full Documentation
CoA including n-hexane content and benzene, SDS, UN 1208 transport documents, REACH compliance, and food-grade documentation for edible oil extraction.
Logistics Support
Experienced in flammable solvent logistics — dedicated road tankers and ISO tanks with bonding, earthing and vapour-return provision, plus drums, for Indian and international delivery.
Storage & Handling Guidelines
Always refer to the full SDS before handling. The following is a summary of key requirements.
- Assess exposure on the basis of neurotoxicity, not just flammability. n-Hexane's occupational exposure limits are far lower than its flammability would suggest — ACGIH lists a TLV of 50 ppm with a skin notation — and control has to be designed to that number.
- Assess co-exposure with MEK and acetone explicitly. Ketone solvents induce the metabolism that produces hexane's neurotoxic metabolite, and the combination is substantially more hazardous than either alone.
- Consider substitution first. Where the solvency permits, isohexane blends and other alternatives avoid the neurotoxicity entirely, and substitution is a more reliable control than ventilation.
- Enclose and extract at source. Hexane neuropathy has been documented in operations relying on general ventilation and personal protection, particularly in adhesive application and manual cleaning.
- Include skin protection in the control strategy. Hexane carries a skin notation because dermal absorption contributes meaningfully to total dose — glove selection matters, and hexane permeates many common glove materials quickly.
- Provide health surveillance where regular exposure occurs. Peripheral neuropathy develops insidiously over weeks to months, and early symptoms — tingling and numbness in the fingers and toes — are easily dismissed by the person experiencing them.
- Respect the low autoignition temperature. At 225 °C, hexane can be ignited by hot surfaces that would not ignite most solvents, including steam lines, heaters and dryer surfaces.
- Bond and earth every transfer. Hexane has very low electrical conductivity and generates static readily, and the flammable range starts at just 1.1%.
- Never siphon by mouth and treat ingestion as an aspiration risk — hexane drawn into the lungs causes chemical pneumonitis and can be fatal.
Hazard Summary
Classification: Flam. Liq. 2 (H225), Repr. 2 (H361f, suspected of damaging fertility), STOT RE 2 (H373, may cause damage to the nervous system through prolonged or repeated exposure), Asp. Tox. 1 (H304), Skin Irrit. 2, STOT SE 3, and hazardous to the aquatic environment. It is by some distance the most hazardous of the common hydrocarbon solvents.
Peripheral neuropathy is the defining hazard: n-hexane is oxidised in the body to 2,5-hexanedione, which cross-links the neurofilament proteins that maintain nerve axon structure. The result is a symmetrical sensorimotor polyneuropathy beginning with numbness and tingling in the hands and feet and progressing to muscle weakness. Onset is gradual, symptoms are easily dismissed early, and recovery after removal from exposure is slow and sometimes incomplete. Outbreaks have occurred in footwear, furniture and electronics manufacturing.
Potentiation by ketone solvents: MEK and acetone induce cytochrome P450 2E1, increasing the conversion of hexane to its neurotoxic metabolite. Neuropathy has been documented at hexane concentrations that would not be expected to cause it in isolation. Assessments that consider each solvent separately understate the risk.
Only the straight chain is neurotoxic: 2-methylpentane and 3-methylpentane cannot form the 2,5-diketone and do not cause neuropathy. This is why a solvent labelled 'hexane' can differ enormously in hazard depending on its n-hexane content, and why that figure belongs on the certificate rather than being inferred from the product name.
Aspiration: hexane has low viscosity and high volatility, so a small quantity entering the lungs spreads rapidly and causes severe chemical pneumonitis. Vomiting must not be induced after ingestion.
Low autoignition temperature: at 225 °C, hexane ignites on hot surfaces that would not ignite most solvents. Steam lines, dryers and heated equipment are credible ignition sources, and a flash point of −22 °C means ignitable vapour is always present.
Benzene content: hexane is produced from refinery streams that may contain benzene, a Category 1A carcinogen. Technical grades hold it to low parts per million and food and pharmaceutical grades much lower still. Confirm the figure on the certificate rather than assuming it.
PPE minimum: chemical goggles, gloves selected against hexane permeation data, antistatic clothing and footwear, with respiratory protection where enclosure and extraction cannot achieve the exposure limit.
Consult the full SDS, assess co-exposure with ketone solvents, and put health surveillance arrangements in place before regular use.
Frequently Asked Questions
Technical and commercial questions about n-Hexane sourcing and specifications.
What is n-hexane used for?
Edible oil extraction is by far the largest use worldwide — soybean, rapeseed, sunflower and rice bran oil are all extracted with hexane, which is then recovered and residual levels in the finished oil controlled by food regulation. Beyond that, hexane is a solvent for rubber and contact adhesives in footwear and leather goods, a diluent and slurry medium in polyolefin polymerisation, a rubber cement solvent, a normal-phase chromatography mobile phase, and a precision degreasing solvent.
Why is n-hexane neurotoxic when other alkanes are not?
Because of the specific metabolite it forms. The body oxidises n-hexane through several steps to 2,5-hexanedione — a diketone with its two carbonyl groups exactly four carbons apart. That spacing lets it react with lysine side chains on neurofilament proteins and cross-link them, which disrupts the structural framework of nerve axons. The axon swells, transport along it fails, and the nerve dies back from its far end. Pentane, heptane and octane do not produce a 2,5-diketone and do not cause this. Neither do hexane's own branched isomers, because the branching prevents oxidation at the required positions. It is an unusually specific structure-toxicity relationship.
Why does co-exposure with MEK matter so much?
Because MEK increases how much hexane gets converted into the harmful metabolite. The oxidation is carried out by cytochrome P450 2E1, and MEK — along with acetone and some other ketones — induces that enzyme, raising its activity. A worker exposed to hexane alone converts a certain fraction; the same worker also exposed to MEK converts more. Documented neuropathy outbreaks have occurred at hexane concentrations that would not have been expected to cause harm, with the ketone co-exposure identified as the reason. Since adhesive formulation, footwear manufacture and electronics cleaning routinely involve both, the combination should be the basis of the assessment.
What does 'hexane' actually mean when I buy it?
Less than the name suggests, which is why the specification matters. Commercial hexane is a fraction from naphtha or natural gas liquids, and it contains a mixture of six-carbon isomers — n-hexane along with 2-methylpentane, 3-methylpentane, methylcyclopentane and cyclohexane. General purpose grades may be only 65% n-hexane; grades sold for demanding extraction can be 95% or higher. Since only the straight-chain isomer is neurotoxic, two products both labelled hexane can present very different occupational hazards. Always specify and verify n-hexane content, and consider whether an isohexane blend — deliberately low in n-hexane — would serve the application.
Why does benzene content matter in a hexane specification?
Because hexane is separated from refinery and natural gas liquid streams that also contain aromatics, and benzene is a Category 1A human carcinogen with occupational limits around 1 part per million or lower. Even small carryover matters when a solvent is used in large volumes with significant worker contact, and it matters more still for edible oil extraction, where any residue reaches consumers. Technical grades typically hold benzene below 100 parts per million, and food and pharmaceutical grades are held far lower. The figure should be on the certificate of analysis for every lot, not assumed from the grade name.
What documentation does Chelora provide?
Every shipment includes a Certificate of Analysis covering n-hexane content, total paraffins, benzene and total aromatics, distillation range, specific gravity, Saybolt colour, non-volatile residue, sulphur, doctor test and acidity; a Safety Data Sheet to GHS and REACH format; UN 1208 Class 3 dangerous goods documentation; food-grade documentation for edible oil extraction where required; an origin certificate; and destination-market certificates where required.
Request a quote or specification sheet
Talk to Chelora's sourcing team about n-Hexane grade, volume, logistics, documentation, and lead times. We respond within one business day.
