Cyclohexanone (CAS 108-94-1; molecular formula C₆H₁₀O; molecular weight 98.15 g/mol) is a cyclic aliphatic ketone shipped as a clear liquid with a closed-cup flash point of 44 °C. This EU & US trade measures on cyclohexanone: status check identifies the active trade-defense instruments, their scope classifications, and the technical specifications that determine which delivered grades are affected. The United States maintains antidumping and countervailing duty orders on cyclohexanone from the People’s Republic of China; the European Union applies a definitive anti-dumping measure on the same origin. Both regimes anchor the scope to the six-membered saturated ketone and use the six-digit harmonized classification 2914.22 as the operative tariff heading.

What Do the Active US and EU Orders Cover in the Cyclohexanone Docket?

US orders were published following final affirmative injury determinations by the U.S. International Trade Commission in Investigation Nos. 701-TA-626 and 731-TA-1455. The antidumping duty order appears at 85 FR 64022 and the countervailing duty order at 85 FR 64018, both dated October 9, 2020. The scope covers all forms and grades of cyclohexanone, including material derived from cyclohexane oxidation or phenol hydrogenation, whether liquid or packaged. The product is currently classified under HTSUS 2914.22.1000. The antidumping cash deposit rate for the China-wide entity is 115.47%. The countervailing duty structure consists of a company-specific rate of 16.96% for one mandatory respondent and an all-others rate of 34.12%.

The EU proceeding was conducted under the basic anti-dumping Regulation (EU) 2016/1036. Provisional duties were imposed by Commission Implementing Regulation (EU) 2020/1172, with published ad valorem duties ranging from 44.4% to 75.1% for sampled and non-sampled Chinese exporters. The definitive measure retained residual duty coverage for non-sampled exporters. The EU scope uses CN code ex 2914 22 00 and TARIC code 2914220010. Mixtures containing more than 50% by weight of cyclohexanone are covered unless the specific mixture is excluded by the TARIC description.

Cyclohexanone from the People’s Republic of China is also within the US Section 301 action covering List 3 products. Because the tariff classification remains HTSUS 2914.22.1000, an additional ad valorem tariff of 25% applies independently of the antidumping and countervailing duty cash deposit requirements at the port of entry.

Cyclohexanone’s physical profile shapes storage, sampling, and downstream metering requirements. At 20 °C, density is 0.947 g/cm³, dynamic viscosity is approximately 2.2 mPa·s, and vapor pressure is 0.45 kPa. The normal boiling point is 155.6 °C, which places the ketone in the medium-boiling oxygenated solvent band. The freezing point of -47 °C prevents crystallization in unheated railcars during most temperate logistics corridors. Water solubility is approximately 8.7 g/100 mL at 20 °C, and the compound is miscible with common aromatic and ketone solvents. Fixed-roof storage tanks require vapor recovery or nitrogen blanketing to control emissions and limit peroxide formation.

Cyclohexanone Oxidation-Grade Specification and ASTM D1078 Distillation Bands

Caprolactam and adipic acid-grade cyclohexanone is specified through a narrow distillation range rather than a single boiling-point value. Under ASTM D1078-03, acceptable material typically shows an initial boiling point not below 152.5 °C and a dry point not above 157.0 °C at 101.3 kPa. Density is controlled to 0.945–0.950 g/cm³ at 20 °C by ASTM D4052-22. Color measured by ASTM D1209-05(2019) is normally ≤10 Pt-Co units for material destined to nylon intermediates. Water content by ASTM D1364-02(2012) is held at ≤0.05 wt% because water accelerates hydrolysis of cyclohexanone oxime and contributes to corrosion in oleum-based Beckmann rearrangement. Purity is typically ≥99.8 wt% by capillary gas chromatography; the residual fraction consists mainly of cyclohexanol, cyclohexane, and light ketones.

Cyclohexanone Production via Phenol Hydrogenation and Cyclohexanol Dehydrogenation

Phenol-based production begins with hydrogenation of phenol to cyclohexanol over a supported nickel catalyst at 120–180 °C and 1.0–4.0 MPa. The cyclohexanol is then vaporized and passed over a copper-zinc or copper-chromite catalyst in a fixed-bed dehydrogenation reactor at 220–280 °C. Per-pass conversion is typically 40–60%, and cyclohexanone selectivity is above 98 mol%. Liquid hourly space velocity is held between 0.3 h⁻¹ and 1.0 h⁻¹. The hydrogen-rich off-gas is cooled, compressed, and reused in phenol hydrogenation. Unconverted cyclohexanol is recovered in a vacuum distillation column; the column reboiler is operated below 180 °C to limit aldol condensation and color-body formation.

Cyclohexane air oxidation remains the dominant route in integrated nylon plants. The oxidation of cyclohexane to KA oil, a mixture of cyclohexanone and cyclohexanol, operates at 140–180 °C and 0.8–1.6 MPa in a sparged reactor. Conversion per pass is kept below 10% to maintain selectivity to KA oil above 85 mol%. The cyclohexanone-to-cyclohexanol ratio in the raw oxidate is generally 0.5:1 to 1:1. After saponification and oxidation of organic acid by-products, the KA oil is distilled. Cyclohexanol is then dehydrogenated in a separate step. This route is the principal source for integrated adipic acid production, where the mixed KA oil is directly oxidized with nitric acid rather than requiring a pure ketone.

When Caprolactam-Grade Cyclohexanone Requires Oxime Yield Above 98.5%

Oximation of cyclohexanone with hydroxylamine sulfate proceeds in a stirred reactor at pH 4.0–5.5 and 70–85 °C. The reaction is a two-phase system in which cyclohexanone is dispersed in an aqueous hydroxylamine salt solution. Ketone conversion per pass is deliberately limited to avoid cyclohexanone loss in the aqueous ammonium sulfate stream. The cyclohexanone oxime is then separated, washed, and fed to the Beckmann rearrangement with oleum at 100–130 °C. Caprolactam selectivity above 98.5% requires cyclohexanol below 0.10 wt% and total unknown organic impurities below 0.20 wt%. Published plant data for specific catalysts and oleum strengths is limited; however, procurement specifications across integrated nylon producers consistently enforce these limits.

In adipic acid production, cyclohexanone is part of the KA oil stream oxidized by nitric acid. The reaction is highly exothermic and requires continuous removal of nitrogen oxide off-gases. High ketone content increases nitric acid consumption relative to cyclohexanol, so producers balance the ketone-to-alcohol ratio to maintain a target stoichiometric ratio of nitric acid to organic carbon. This balance is one reason that trade-restricted cyclohexanone entering merchant commerce is often assessed for oxidation grade, not merely solvent purity.

Solvent Balance in Vinyl Organosol Systems and ASTM D1209 Color Control

Cyclohexanone is a strong solvent for vinyl chloride-vinyl acetate copolymers and is used in coating, printing ink, and polyurethane elastomer formulations. Its Hansen solubility parameters are approximately δD 17.8 MPa^1/2, δP 6.3 MPa^1/2, and δH 5.1 MPa^1/2. This places cyclohexanone within the solubility sphere of polar vinyl resins and cellulose nitrate. In organosol coating formulations, Brookfield viscosity is monitored by ASTM D2196-20 at 25 °C; cyclohexanone reduces viscosity more efficiently than aromatic diluents while maintaining resin solvency. The solvent is usually blended with cyclohexanone-free diluents to control dry time because the evaporation rate relative to n-butyl acetate is below 0.3 under the same airflow conditions.

Cyclohexanone also enters resins when condensed with formaldehyde under alkaline catalysis. The reaction forms a low-molecular-weight aliphatic cyclic ketone resin with a softening range of 60–90 °C, used as a hard resin in flexographic and intaglio inks. Formaldehyde-to-cyclohexanone molar ratios are typically 1.2:1 to 2.0:1. Residual free formaldehyde is controlled to 0.10 wt% or lower under REACH and OSHA communication requirements. Color stability in storage is evaluated by ASTM D1209-05(2019) because carbonyl condensation products can shift Pt-Co values upward during prolonged heating.

Occupational exposure limits for cyclohexanone include an OSHA permissible exposure limit of 50 ppm (200 mg/m³) as an 8-hour time-weighted average. The ACGIH threshold limit value is 20 ppm. The EU indicative occupational exposure limit is 10 ppm for an 8-hour reference period in most harmonized implementations. Cyclohexanone should not be stored with strong oxidizing agents, strong acids, or alkali at elevated temperatures because exothermic aldol condensation can occur. Contact with sodium hydroxide or potassium hydroxide above 60 °C can generate cyclohexylidene self-condensation products and raise viscosity. Bulk storage in carbon steel is standard; for color-critical applications, stainless steel or lined carbon steel is specified. Nitrogen blanketing at 0.5–1.0 kPa oxygen-free pressure reduces peroxide formation and stabilizes Pt-Co color during long-term storage.