“Hexane” is a family, not one product. n-Hexane (CAS 110-54-3) is the straight-chain isomer, and it is the only one NIOSH associates with peripheral neuropathy — its REL is 50 ppm against an OSHA PEL of 500 ppm. Mixed hexanes are the branched isomers, with a NIOSH REL of 100 ppm and no OSHA PEL. Cyclohexane (CAS 110-82-7) is a ring compound with its own 300 ppm limit.
What are the three products sold as "hexane"?
Order "hexane" from three suppliers and you can receive three different materials. All share the formula C6H14 except cyclohexane, and all look and smell alike, but their exposure limits and health effects diverge sharply.
- n-Hexane — the single straight-chain isomer, CAS 110-54-3. Sold at 95% or higher purity for extraction and analytical work. This is the regulated one.
- Mixed hexanes (hexane isomers) — a blend that NIOSH defines as all isomers of hexane except n-hexane: 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, and related branched structures. Commercial "hexanes" typically still contain some n-hexane, which is why the blend assay matters.
- Cyclohexane — C6H12, CAS 110-82-7, a six-carbon ring rather than a chain. It is a different chemical entirely, freezes at 44 °F, and is used mainly as a nylon feedstock and a resin solvent.
How do n-hexane, mixed hexanes, and cyclohexane compare?
All values below come from the NIOSH Pocket Guide to Chemical Hazards and PubChem.
| Property | n-Hexane | Mixed hexanes (isomers) | Cyclohexane |
|---|---|---|---|
| CAS Number | 110-54-3 | Blend — no single CAS | 110-82-7 |
| Formula | C6H14 | C6H14 | C6H12 |
| Molecular weight | 86.2 g/mol | 86.2 g/mol | 84.2 g/mol |
| Boiling point | 68.7 °C (156 °F) | 50–63 °C (122–145 °F) | 80.7 °C (177 °F) |
| Freezing point | −95 °C (−139 °F) | −154 to −100 °C (−245 to −148 °F) | 6.5 °C (44 °F) |
| Specific gravity | 0.66 | 0.65–0.66 | 0.78 |
| Weight per US gallon | 5.50 lb/gal | ~5.45 lb/gal | 6.49 lb/gal |
| Flash point | −22 °C (−7 °F) | −48 to −7 °C (−54 to 19 °F) | −18 °C (0 °F) |
| Vapor pressure at 20 °C | 124 mmHg | Not established | 78 mmHg |
| Flammability class | Class IB | Class IB | Class IB |
| LEL / UEL | 1.1% / 7.5% | Not established | 1.3% / 8% |
| Water solubility | 0.002% | Insoluble | Insoluble |
| OSHA PEL (TWA) | 500 ppm (1800 mg/m3) | None established | 300 ppm (1050 mg/m3) |
| NIOSH REL (TWA) | 50 ppm (180 mg/m3) | 100 ppm (350 mg/m3); C 510 ppm | 300 ppm (1050 mg/m3) |
| IDLH | 1100 ppm | Not determined | 1300 ppm |
| DOT ID / Guide | UN1208 / Guide 128 | UN1208 / Guide 128 | UN1145 / Guide 128 |
To convert these densities into drum, tote, or tank-truck weights for a specific fill, use the RightPath chemical density and volume calculators.
Why does the n-hexane distinction matter?
Because the health effects are not the same. NIOSH lists the symptoms of n-hexane exposure as eye and nose irritation; nausea and headache; peripheral neuropathy, including numb extremities and muscle weakness; dermatitis; dizziness; and chemical pneumonitis on aspiration. The NIOSH entry for hexane isomers lists eye, skin, and respiratory irritation; headache; dizziness; nausea; chemical pneumonitis; and dermatitis — with no peripheral neuropathy.
That difference is why NIOSH sets the n-hexane REL at 50 ppm, ten times lower than the OSHA PEL of 500 ppm, and why many EHS programs specify low-n-hexane blends or substitute mixed hexanes wherever the process allows. If your industrial hygiene program is written around "hexane," confirm which material is actually in the tank — the exposure limit you are monitoring against depends on it.
Section 3 of the Safety Data Sheet gives the concentration range of n-hexane in a mixed-hexane product. See how to read a Safety Data Sheet for the full section breakdown.
Which hexane grade should you specify?
| Application | Typical specification | Why |
|---|---|---|
| Edible oil and oilseed extraction | n-Hexane 95% or extraction-grade hexanes | Narrow boiling range and consistent solvent recovery |
| HPLC and GC mobile phases | n-Hexane, HPLC grade | Low UV absorbance and low non-volatile residue |
| Pharmaceutical crystallization | n-Hexane, high purity | Defined single-isomer behavior and reproducible solubility |
| Adhesives, inks, and cleaning | Mixed hexanes | Lower n-hexane content reduces neurotoxicity exposure risk |
| Degreasing and general solvent duty | Mixed hexanes | Cheaper, and single-isomer performance is not required |
| Nylon 6 and nylon 6,6 feedstock | Cyclohexane | Oxidized to adipic acid and caprolactam |
| Resin, wax, and rubber solvency | Cyclohexane | Higher boiling point and stronger solvency than chain hexanes |
For deeper background on the chemical itself, see the Hexane properties, uses, and bulk supply guide. For what analytical grade designations actually mean, see ACS vs HPLC vs USP grade solvents.
How should hexane be stored and shipped?
All three are Class IB flammable liquids: flash point below 73 °F and boiling point at or above 100 °F. n-Hexane flashes at −7 °F and cyclohexane at 0 °F, so both require flammable-liquid storage, bonding and grounding during transfer, and ignition-source control. All three are incompatible with strong oxidizers.
Chain hexanes ship under UN1208 with ERG Guide 128; cyclohexane ships under UN1145, also Guide 128. Confirm the packing group and proper shipping name against Section 14 of the product SDS before generating a bill of lading. For the general framework, see DOT hazmat classes for solvents.
Cyclohexane has one storage quirk the chain hexanes do not: it freezes at 44 °F. Drums and totes stored in an unheated warehouse through winter can solidify and need to be re-liquefied before transfer.
What hexane grades and sizes does RightPath stock?
RightPath Industries is a Pittsburgh-headquartered bulk chemical distributor carrying over 8,000 chemicals, including all three hexane products.
| Product | Typical grades | Packaging |
|---|---|---|
| Hexane, n- 95% | Technical, extraction, high purity | 5-gal pails, 55-gal drums, IBC totes, tank truck |
| Hexanes (mixed isomers) | Technical, ACS, HPLC | 4L cases, 5-gal pails, 55-gal drums, tank truck |
| Cyclohexane | Technical, ACS, HPLC | 55-gal drums, IBC totes, tank truck, railcar |
The full aliphatic and aromatic solvent range is listed on the bulk solvent supplier page. To pick a container size against your draw rate, see Drum vs IBC Tote vs Bulk.
How do you order hexane from RightPath?
- State which material you need — n-hexane 95%, mixed hexanes, or cyclohexane — and the grade (technical, ACS, or HPLC).
- If n-hexane content is controlled by your EHS program, say so, and we will quote against the assay range you need.
- Give the monthly or annual volume and delivery point so freight is priced into the quote, not added afterward.
- Request bulk pricing for an all-in landed-cost quote, typically same day.
- Pull the current sheet from the SDS library and request the lot COA before first shipment.
Frequently asked questions
Is hexane the same as n-hexane?
No. n-Hexane is one specific isomer, CAS 110-54-3. Commercial "hexane" or "hexanes" is usually a blend of C6H14 isomers that still contains some n-hexane. Because the exposure limits differ — a NIOSH REL of 50 ppm for n-hexane versus 100 ppm for the isomer blend — the two are not interchangeable on a specification sheet.
Which hexane is the toxic one?
n-Hexane. NIOSH lists peripheral neuropathy, including numb extremities and muscle weakness, among its exposure symptoms. The entry for hexane isomers does not list peripheral neuropathy. All hexanes cause irritation, dizziness, and dermatitis, and all present chemical pneumonitis risk if aspirated.
What is the OSHA exposure limit for hexane?
The OSHA PEL for n-hexane is 500 ppm (1800 mg/m3) as an 8-hour TWA. NIOSH recommends 50 ppm (180 mg/m3). OSHA has no PEL for the other hexane isomers; NIOSH recommends 100 ppm TWA with a 510 ppm 15-minute ceiling. Cyclohexane has an OSHA PEL and NIOSH REL of 300 ppm.
Is cyclohexane a type of hexane?
No. Cyclohexane is C6H12, a saturated six-carbon ring, while the hexanes are C6H14 open chains. Cyclohexane boils higher (80.7 °C versus 68.7 °C), is denser (0.78 versus 0.66), and freezes at 44 °F. It ships under a different UN number, UN1145.
How much does a gallon of hexane weigh?
About 5.5 pounds per US gallon for n-hexane, based on a specific gravity of 0.66. Cyclohexane weighs about 6.49 pounds per gallon at a specific gravity of 0.78. Hexane is one of the lightest common industrial solvents, which matters when you are comparing a price quoted per pound against one quoted per gallon.
Can I substitute mixed hexanes for n-hexane?
Often yes for degreasing, adhesives, and general solvent duty, and it usually lowers both cost and neurotoxicity exposure risk. Not for HPLC mobile phases, pharmaceutical crystallization, or any validated process where the boiling range and single-isomer solubility behavior are part of the specification.
Authoritative sources
- NIOSH Pocket Guide — n-Hexane
- NIOSH Pocket Guide — Hexane isomers
- NIOSH Pocket Guide — Cyclohexane
- PubChem CID 8058 — n-Hexane
- PubChem CID 8078 — Cyclohexane
Need a quote? Request bulk pricing from RightPath Industries for n-hexane, mixed hexanes, or cyclohexane in drums, totes, tank truck, or railcar.