Substance profile
Cyclohexane
Cyclohexane is a colorless mobile liquid with a solvent odor; pungent when impure.
01 · Identification
What Cyclohexane is
Cyclohexane is a colorless mobile liquid with a solvent odor; pungent when impure. Its molecular formula is C6H12 and its molecular weight is 84.16 g/mol. It boils at 80.7 °C, melts at 6.5 °C.
Under the GHS it carries the signal word Danger. It is classed as flammable agents - 3rd degree.
02 · Identifiers
Cyclohexane identifiers and molecular data
Cyclohexane CAS number and EC number
Cyclohexane molecular formula and molecular weight
03 · GHS classification
Cyclohexane hazard classification
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
Cyclohexane pictograms and signal word
Cyclohexane hazard class and category
| Hazard class | Category | From code | Pictogram |
|---|---|---|---|
| Flammable liquids GHS chapter 2.6 | Category 2 | H225 | GHS02 |
| Skin corrosion/irritation GHS chapter 3.2 | Category 2 | H315 | GHS07 |
| Specific target organ toxicity - single exposure GHS chapter 3.8 | Category 3 narcotic | H336 | GHS07 |
| Aspiration hazard GHS chapter 3.10 | Category 1 | H304 | GHS08 |
| Hazardous to the aquatic environment - acute GHS chapter 4.1 | Category 1 | H400 | GHS09 |
| Hazardous to the aquatic environment - chronic GHS chapter 4.1 | Category 1 | H410 | GHS09 |
Cyclohexane hazard statements (H-codes)
| Code | Hazard statement |
|---|---|
| H225 | Highly flammable liquid and vapour. |
| H304 | May be fatal if swallowed and enters airways. |
| H336 | May cause drowsiness or dizziness. |
| H315 | Causes skin irritation. |
| H400 | Very toxic to aquatic life. |
| H410 | Very toxic to aquatic life with long lasting effects. |
This page lists only the codes assigned to Cyclohexane. The full reference lives on the hazard statements hub, the precautionary statements hub and the GHS pictograms hub.
Safety Data Sheet
Getting an SDS for Cyclohexane
A Safety Data Sheet is written for a product, not for a substance: the supplier of the grade you actually buy issues it, so two suppliers of Cyclohexane issue two different sheets. That is why there is no single authoritative SDS for a substance to download — what there is, is the job of collecting the sheets for the products you hold and keeping them current as suppliers revise them.
04 · Precautionary statements
Cyclohexane precautionary statements
CLP Annex VI assigns 14 precautionary statements to Cyclohexane. They are grouped the way a label groups them: what to do before handling, what to do when something has already happened, how to store it and how to dispose of it.
Prevention
What to do before and during handling so the hazard never happens.
Response
What to do once exposure, spillage or fire has already happened.
Disposal
What has to happen to the contents and the empty container.
Reading the notation. … is a blank the supplier fills in — not a truncated sentence.· [square brackets] mark a part printed only when it applies.
05 · Names in the regulation
Cyclohexane name in 23 EU languages
CLP Annex VI Part 3 is published in every language edition of the regulation, and the identification column is written out in each of them. Nothing below is translated by us: each line is the name as that edition prints it. Under Art. 18(2) the substance name from Annex VI is a lawful product identifier, so this is the wording to put on a label going to that market — and where the cell lists several designations, any one of them qualifies.
| Language | Name in CLP Annex VI Part 3 |
|---|---|
| Bulgarian български | циклохексан |
| Spanish español | Ciclohexano |
| Czech čeština | cyklohexan |
| Danish dansk | cyclohexan |
| German Deutsch | Cyclohexan |
| Estonian eesti | tsükloheksaan |
| Greek ελληνικά | κυκλοεξάνιο |
| English English | cyclohexane |
| French français | cyclohexane |
| Croatian hrvatski | cikloheksan |
| Italian italiano | cicloesano |
| Latvian latviešu | cikloheksāns |
| Lithuanian lietuvių | cikloheksanas |
| Hungarian magyar | ciklohexán |
| Maltese Malti | ċikloessan |
| Dutch Nederlands | cyclohexaan |
| Polish polski | cykloheksan |
| Portuguese português | ciclo-hexano |
| Romanian română | ciclohexan |
| Slovak slovenčina | cyklohexán |
| Slovenian slovenščina | cikloheksan |
| Finnish suomi | sykloheksaani |
| Swedish svenska | cyklohexan |
All 23 language editions of Annex VI carry this entry. Irish is the twenty-fourth official EU language and has no line here for a different reason: no consolidated CLP text has ever been published in Irish, so there is no Irish edition of Annex VI to quote a name from. Source: consolidated CLP, CELEX 02008R1272, language editions. © European Union, https://eur-lex.europa.eu — only the electronic Official Journal of the European Union is authentic.
06 · Label elements
Cyclohexane GHS label elements
Everything CLP Annex VI fixes for Cyclohexane, laid out the way it appears on a label. The greyed lines are the parts only the supplier can fill in.
Danger
Cyclohexane
- Highly flammable liquid and vapour.
- May be fatal if swallowed and enters airways.
- May cause drowsiness or dizziness.
- Causes skin irritation.
- Very toxic to aquatic life.
- Very toxic to aquatic life with long lasting effects.
- Keep away from heat, hot surfaces, sparks, open flames and other ignition sources. No smoking.
- Keep container tightly closed.
- Use explosion-proof [electrical/ventilating/lighting/…] equipment.
- Use only non-sparking tools.
- Wash … thoroughly after handling.
- Avoid release to the environment.
- Wear protective gloves/protective clothing/eye protection/face protection/hearing protection/…
- IF ON SKIN:
- Get medical advice/attention.
- If skin irritation occurs:
- Wash with plenty of water/…
- Collect spillage.
- Store in a well-ventilated place.
- Dispose of contents/container to …
Supplier name, address and telephone number· Product identifier·Nominal quantity
Need this as an actual label? Open Cyclohexane in the GHS label constructor →
07 · Health hazards
Cyclohexane health hazards and exposure limits
Cyclohexane hazard summary
Exposed animals develop narcosis and minimal histopathological liver changes. Some authors report an odor threshold of 25 ppm. [ACGIH] A skin, eye, and respiratory tract irritant; Inhalation of high concentrations may cause CNS effects; [ICSC]
Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
Cyclohexane occupational exposure limits
| Limit | Value | Source |
|---|---|---|
| PEL | 300.0 [ppm] | Haz-Map, Information on Hazardous Chemicals and Occupational Diseases |
| PEL | 300 ppm (1050 mg/m³) | Occupational Safety and Health Administration (OSHA) |
| PEL | TWA 300 ppm (1050 mg/m3) | The National Institute for Occupational Safety and Health (NIOSH) |
| REL | 300 ppm (1050 mg/m³) | Occupational Safety and Health Administration (OSHA) |
| REL | TWA 300 ppm (1050 mg/m3) | The National Institute for Occupational Safety and Health (NIOSH) |
| IDLH | 1300 ppm ; Based on 10% of the lower explosive limit. (NIOSH, 2024) | CAMEO Chemicals |
| IDLH | 1300.0 [ppm] | Haz-Map, Information on Hazardous Chemicals and Occupational Diseases |
| IDLH | 1300 ppm | Occupational Safety and Health Administration (OSHA) |
These are United States values. The European Union sets its own indicative and binding limits, and the figure that applies at a given workplace is the one in the local regulation — not the one shown here.
08 · Physical and chemical properties
Cyclohexane properties
Every value is shown with the conditions it was measured under and the source it came from. Where sources disagree, all values are listed rather than one being picked — the difference is usually a different form of the substance, not an error.
Cyclohexane boiling point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Boiling point | 80.7 °C (177.3 °F) | at 760 mmHg | HSDB |
| 80.56 °C (177 °F) | NIOSH | ||
| 80.72 °C (177.3 °F) | at 760 mmHg | CAMEO |
Cyclohexane melting point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Melting point | 6.47 °C (43.6 °F) | HSDB | |
| 6.67 °C (44 °F) | NIOSH | ||
| 6.5 °C (43.7 °F) | CAMEO |
Cyclohexane density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Density | 0.78 g/cm³ | NIOSH | |
| 0.7781 g/cm³ | at 20 °C | HSDB | |
| 0.779 g/cm³ | at 20 °C | CAMEO |
Cyclohexane solubility
| Property | Value | Conditions | Source |
|---|---|---|---|
| Solubility | Miscible in ethanol, ether, acetone, benzene, ligroin, carbon tetrachloride | HSDB | |
| Solubility in water at 23.5 °C (w/w): 0.0052% | at 23.5 °C | HSDB | |
| In water, 55 mg/L at 25 °C | at 25 °C | HSDB |
Cyclohexane vapor pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor pressure | 78 mmHg | NIOSH | |
| 97.508 mmHg | at 25 °C | HSDB | |
| 96.9 mmHg | at 25 °C | HSDB |
Cyclohexane flash point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Flash point | -17.22 °C (1 °F) | HSDB | |
| -17.78 °C (0 °F) | NIOSH | ||
| -20 °C (-4 °F) | CAMEO |
Cyclohexane autoignition temperature
| Property | Value | Conditions | Source |
|---|---|---|---|
| Autoignition temperature | 245 °C (473 °F) | HSDB | |
| 270 °C (518 °F) | CAMEO | ||
| 260 °C (500 °F) | ICSC |
Cyclohexane lower explosive limit (LEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Lower explosive limit (LEL) | 1.3 % by volume | HSDB |
Cyclohexane upper explosive limit (UEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Upper explosive limit (UEL) | 8 % by volume | HSDB | |
| 8.4 % by volume | HSDB |
Cyclohexane vapor density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor density | 2.98 (air = 1) | HSDB | |
| 2.9 (air = 1) | CAMEO |
Cyclohexane odor threshold
| Property | Value | Conditions | Source |
|---|---|---|---|
| Odor threshold | The reported odor threshold is approximately 25 ppm. | HSDB | |
| Detection in air: 3.56x10-5 g/l | HSDB | ||
| Detection in air: 2.02x10-4 g/l | HSDB |
Cyclohexane critical temperature and pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Critical temperature and pressure | 280.3 °C (536.5 °F) | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
09 · Fire and explosion
Cyclohexane fire and explosion behaviour
These are descriptions rather than measured values, so they are kept out of the table above and quoted here with the source that reported them.
Cyclohexane fire potential
Dangerous fire hazard when exposed to heat or flame; can react with oxidizing materials.
Source: Hazardous Substances Data Bank (HSDB)
10 · Handling and storage
Cyclohexane storage and handling
Cyclohexane safe storage
Fireproof. Provision to contain effluent from fire extinguishing. Separated from strong oxidants. Store in an area without drain or sewer access.
Source: ILO-WHO International Chemical Safety Cards (ICSCs)
Cyclohexane storage conditions
Keep container tightly closed in a dry and well-ventilated place. Containers which are opened must be carefully resealed and kept upright to prevent leakage. Store under inert gas.
Source: Hazardous Substances Data Bank (HSDB)
Cyclohexane incompatible materials
Oxidizers.
Source: Hazardous Substances Data Bank (HSDB)
Cyclohexane reactivity
Liquid nitrogen dioxide was fed into a nitration column containing hot CYCLOHEXANE, due to an error. An explosion resulted [MCA Case History 128(1962)] Incompatible with strong oxidizers.
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Cyclohexane in the storage compatibility matrix →
11 · Transport
Cyclohexane UN number and transport classification
Transport classification is a separate system from the GHS classification above. It decides how a package is marked and how a load may be carried; it does not follow from the workplace label, and the workplace label does not follow from it. The entries below are linked by CAS number, never by name.
Cyclohexane under UN 1145 — shipping name, class and packing group
Europe · ADR 2025, Table A
| Proper shipping name (3.1.2) | Class | Classification code | PG | Labels (column 5) |
|---|---|---|---|---|
| CYCLOHEXANE | 3 | F1 | II | |
Source: ADR 2025, Table A of Chapter 3.2 · ECE/TRANS/352 Vol. I (UNECE). Class 3 is “Flammable liquids” (ADR 2.1.1.1).
United States · 49 CFR 172.101 Hazardous Materials Table
| Proper shipping name (column 2) | Class or division | PG | Labels (column 6) |
|---|---|---|---|
| Cyclohexane | 3 | II | |
Source: 49 CFR 172.101 Hazardous Materials Table · eCFR, revision 2026-08-03. Class 3 is “Flammable and combustible liquid” (49 CFR 173.2).
12 · Questions
Cyclohexane — frequently asked questions
What is the CAS number of Cyclohexane?
The CAS number of Cyclohexane is 110-82-7. Its EC number is 203-806-2.
What is the chemical formula of Cyclohexane?
The molecular formula of Cyclohexane is C6H12 and its molecular weight is 84.16 g/mol.
What does a Cyclohexane label have to show?
Under CLP Annex VI the label for Cyclohexane carries the pictograms Flame, Health hazard, Exclamation mark and Environment and the signal word is Danger.
Is Cyclohexane flammable?
Yes. CLP Annex VI assigns Cyclohexane H225 — highly flammable liquid and vapour. The flash point reported for it is -17.22 °C (1 °F) (HSDB).
Is Cyclohexane a carcinogen?
CLP Annex VI records no harmonised carcinogenicity classification for Cyclohexane. Annex VI is a list of agreed classifications, not a list of substances found safe, so this is an absence of a classification rather than a clean bill of health.
What is the exposure limit for Cyclohexane?
The US occupational exposure limit reported for Cyclohexane is 300.0 [ppm] (Haz-Map, Information on Hazardous Chemicals and Occupational Diseases). Limits differ by country: the EU sets its own indicative and binding values, and the figure that applies at a given workplace is the one in the local regulation.
What is the boiling point of Cyclohexane?
The boiling point reported for Cyclohexane is 80.7 °C (177.3 °F), at 760 mmHg (HSDB).
What is the melting point of Cyclohexane?
The melting point reported for Cyclohexane is 6.47 °C (43.6 °F) (HSDB).
How should Cyclohexane be stored?
CLP Annex VI assigns Cyclohexane the storage statement P403. Keep container tightly closed in a dry and well-ventilated place. Containers which are opened must be carefully resealed and kept upright to prevent leakage. Store under inert gas. (Hazardous Substances Data Bank (HSDB))
Nearby
Substances next to Cyclohexane
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