Cyclohexanone: Properties, Uses & Lab Handling Guide

Cyclohexanone is a versatile alicyclic ketone widely used as an industrial solvent, chemical intermediate, and analytical reagent in research laboratories worldwide.

Molecular Formula

C₆H₁₀O

Molecular Weight

98.14 g/mol

Boiling Point

155.6 °C at 760 mmHg

Melting Point

-31 °C

Density

0.947 g/mL at 25 °C

Flash Point

43 °C (closed cup)

CAS Number

108-94-1

Appearance

Colorless to pale yellow liquid with a peppermint-like odor

Chemical Properties and Structure

Cyclohexanone (CAS 108-94-1) is a cyclic ketone with the molecular formula C₆H₁₀O and a molecular weight of 98.14 g/mol. Its structure consists of a six-membered carbocyclic ring bearing a ketone carbonyl group (C=O) at the 1-position, making it the simplest cyclic ketone of the cyclohexane series.

The compound is a colorless to pale yellow, mobile liquid at room temperature with a characteristic peppermint- or acetone-like odor. Key physical constants include a boiling point of approximately 155.6 °C, a melting point of −31 °C, and a density of about 0.947 g/mL at 25 °C. Cyclohexanone is miscible with most common organic solvents—including ethanol, diethyl ether, acetone, and chloroform—and is only slightly soluble in water (approximately 8.6 g/100 mL at 20 °C).

Chemically, the carbonyl group renders cyclohexanone reactive toward nucleophilic addition, condensation reactions, and enolization. It undergoes aldol-type condensations, reacts with hydroxylamine to form cyclohexanone oxime (a precursor to caprolactam), and can be oxidized or reduced under standard laboratory conditions. The α-hydrogen atoms adjacent to the carbonyl are mildly acidic (pKa ≈ 20 in DMSO), enabling enolate chemistry with strong bases.

Industrial and Laboratory Applications

Cyclohexanone is one of the most commercially significant cyclic ketones and serves multiple roles across industrial and research settings.

Solvent Applications: Its moderate polarity and high boiling point make cyclohexanone an excellent solvent for resins, lacquers, paints, varnishes, and polymer coatings. It is widely used to dissolve cellulose esters, nitrocellulose, polyvinyl chloride (PVC), and various synthetic rubbers. In analytical chemistry and materials research, it is used to dissolve polymeric samples prior to chromatographic or spectroscopic analysis.

Chemical Intermediate: The most prominent industrial use of cyclohexanone is as an intermediate in the manufacture of nylon-6 and nylon-6,6. Cyclohexanone is oxidized with nitric acid or converted via cyclohexanone oxime (through Beckmann rearrangement) to ε-caprolactam, the monomer for nylon-6. It is also an intermediate in the synthesis of adipic acid.

Research and Synthesis: In academic and pharmaceutical research, cyclohexanone serves as a starting material for the synthesis of complex organic molecules. It participates in enolate alkylation, Wittig reactions, Grignard additions, and catalytic asymmetric reactions. Its well-defined ring geometry makes it a model substrate for studying stereochemistry and conformational analysis.

Analytical Use: Cyclohexanone is used as a solvent in HPLC sample preparation, thin-layer chromatography, and as a reference standard in certain GC calibrations.

Safe Handling, Storage, and Disposal

Cyclohexanone is classified as a flammable liquid (Flash point 43 °C, closed cup) and poses hazards through inhalation, skin contact, and ingestion. Researchers and lab managers must follow appropriate safety protocols when handling this reagent.

Personal Protective Equipment (PPE): Always wear chemical-splash safety goggles, nitrile or neoprene gloves, and a lab coat. When handling large quantities or working in poorly ventilated areas, use a NIOSH-approved organic vapor respirator. Avoid wearing contact lenses.

Ventilation: Use cyclohexanone exclusively in a certified chemical fume hood or well-ventilated enclosure. Its vapor can accumulate and reach explosive concentrations (LEL approximately 1.1% v/v in air) in confined spaces.

Storage: Store in a tightly sealed container in a cool, dry, well-ventilated flammables storage cabinet away from heat sources, open flames, oxidizing agents, and strong acids or bases. Recommended storage temperature is below 25 °C. Keep away from incompatible materials including strong oxidizers and concentrated acids.

Spill Response: Absorb small spills with inert material (e.g., vermiculite or dry sand), collect in a labeled waste container, and dispose of as hazardous chemical waste in accordance with local regulations. Eliminate all ignition sources immediately upon a spill.

Waste Disposal: Cyclohexanone waste must be disposed of in accordance with national, regional, and institutional regulations for flammable organic solvent waste. Do not pour down the drain or into the environment.

First Aid: In case of skin contact, wash thoroughly with soap and water. For eye contact, flush with copious amounts of water for at least 15 minutes and seek medical attention. If inhaled in high concentrations, move to fresh air immediately and seek medical evaluation.

Purity, Grades, and Specifications

Cyclohexanone is commercially available in several purity grades to meet the diverse needs of industrial, analytical, and synthetic research applications. Selecting the appropriate grade is essential to ensure experimental reproducibility and regulatory compliance.

Technical Grade: Typically ≥99.0% purity by GC. Suitable for industrial solvent applications, polymer processing, and non-critical synthesis where trace impurities are acceptable.

Reagent / ACS Grade: Meets specifications of the American Chemical Society (ACS) for use in analytical procedures. Typical purity ≥99.0% by GC with controlled limits on water content, non-volatile residue, and specific metallic impurities. Recommended for general laboratory synthesis, solvent applications in analytical chemistry, and preparative procedures.

HPLC / Spectroscopic Grade: Ultra-high purity formulations (≥99.8% by GC) with very low UV absorbance and particulate levels. Suitable for use as a mobile-phase additive or sample solvent in high-sensitivity chromatographic and spectroscopic analyses.

Anhydrous Grade: Specially dried to minimize water content, suitable for moisture-sensitive reactions such as enolate chemistry, Grignard reactions, and organometallic synthesis.

When ordering cyclohexanone from Aladdin Scientific (SKU: C1530108), consult the product Certificate of Analysis (CoA) for the exact purity, water content, and trace metal specifications applicable to your specific lot. Contact our technical support team for custom purity or packaging requirements.

Regulatory Status and Compliance

Understanding the regulatory landscape for cyclohexanone is important for procurement, shipping, and safe laboratory operation.

GHS Classification: Under the Globally Harmonized System of Classification and Labelling of Chemicals (GHS), cyclohexanone is classified as a Flammable Liquid Category 3 (H226: Flammable liquid and vapor), and carries hazard statements for skin and eye irritation (H315, H319), and may cause respiratory irritation (H335). The precautionary statements include keeping away from heat and ignition sources, use of PPE, and proper ventilation.

Transport Regulations: Cyclohexanone is regulated as a hazardous material for transport under international and national frameworks. It is classified as UN 1915, Class 3 (Flammable Liquid), Packing Group III under IATA, IMDG, and DOT regulations. Shipments must be properly labeled, placarded, and accompanied by a Safety Data Sheet (SDS).

REACH and RoHS: Cyclohexanone is listed on the REACH candidate substance inventory monitoring list; users in the European Union should verify current REACH compliance status and any applicable authorization or restriction requirements before use or importation.

Occupational Exposure Limits (OELs): Many regulatory bodies have established OELs for cyclohexanone. For example, the OSHA PEL is 50 ppm (TWA, 8-hour) and the ACGIH TLV is 20 ppm (TWA). Laboratories should implement engineering controls and monitoring to remain within permissible exposure limits.

Always consult the current Safety Data Sheet (SDS) provided with your Aladdin Scientific product for the most up-to-date regulatory and safety information applicable to your jurisdiction.

Frequently asked questions

What is cyclohexanone commonly used for in research laboratories?

Cyclohexanone is used as a versatile organic solvent for dissolving resins, polymers, and cellulose derivatives, and as a synthetic building block for complex organic molecules. It is also employed as a chemical intermediate in the preparation of caprolactam (nylon-6 precursor) and adipic acid, and as a solvent in HPLC sample preparation and chromatographic applications.

What grade of cyclohexanone should I order for HPLC or sensitive analytical work?

For HPLC and high-sensitivity spectroscopic applications, select HPLC or Spectroscopic grade cyclohexanone, which offers purity ≥99.8% by GC and very low UV absorbance. For general synthesis and solvent use, Reagent/ACS grade (≥99.0% GC purity) is typically sufficient. Always check the Certificate of Analysis for lot-specific data.

How should cyclohexanone be stored in the laboratory?

Cyclohexanone should be stored in a tightly sealed container in a cool (below 25 °C), dry, well-ventilated flammables storage cabinet, away from heat, open flames, oxidizing agents, and strong acids or bases. Always keep the container away from incompatible materials and ensure it is clearly labeled.

Is cyclohexanone water-soluble, and can it be disposed of down the drain?

Cyclohexanone has limited water solubility (approximately 8.6 g/100 mL at 20 °C) and must NOT be disposed of down the drain. It must be collected as flammable organic solvent waste and disposed of in accordance with all applicable national, regional, and institutional hazardous waste regulations.

What personal protective equipment is required when handling cyclohexanone?

When handling cyclohexanone, you should wear chemical-splash safety goggles, nitrile or neoprene gloves, and a lab coat. Work in a certified fume hood at all times. If large volumes are involved or ventilation is inadequate, use a NIOSH-approved organic vapor respirator. Avoid wearing contact lenses.

References

1. Lide, D.R. (Ed.). CRC Handbook of Chemistry and Physics, 97th Edition. CRC Press, Boca Raton, FL.
2. Cyclohexanone Safety Data Sheet. Aladdin Scientific, SKU C1530108. Retrieved from product page.
3. American Chemical Society. Reagent Chemicals: Specifications and Procedures for Reagents and Standard-Grade Reference Materials, 10th Edition. ACS, Washington, DC.
4. NIOSH Pocket Guide to Chemical Hazards: Cyclohexanone. National Institute for Occupational Safety and Health, U.S. Centers for Disease Control and Prevention.
5. European Chemicals Agency (ECHA). Cyclohexanone Substance Information. REACH Registration Dossier.

Products are supplied for research and development use only. Not for use in humans, animals, diagnosis, or therapy.