Cumene
Isopropylbenzene, made to be oxidised. The cumene process supplies nearly all the world's phenol, with acetone as an unavoidable co-product.
Molecular Structure
What is Cumene?
Cumene is a benzene ring carrying an isopropyl group — a branched three-carbon chain attached through its middle carbon. It is a clear liquid boiling at 152.4 °C with a sharp, penetrating odour.
The carbon joining the chain to the ring is tertiary and benzylic, so the radical formed by pulling off its single hydrogen is stabilised twice over. Air will do that on its own, converting cumene to cumene hydroperoxide — a reaction that is deliberately run in the phenol process, and which happens slowly and unhelpfully in any drum left with air in the headspace.
The Hock process exploits it: cumene is oxidised to the hydroperoxide, then cleaved with acid into phenol and acetone. The stoichiometry is fixed at roughly 1 tonne of phenol to 0.6 tonnes of acetone, which is why the two markets are permanently coupled to each other.
Chelora supplies cumene at ≥99.5 wt% with peroxide content certified low and phenol and sulfur controlled for oxidation service. Shipped with inhibitor and headspace guidance, since cumene forms peroxides on standing in air.
Quick Reference
Key Physical & Chemical Properties
Structure & Bonding
One hydrogen does the work. The tertiary benzylic C–H on the isopropyl group is the weakest bond in the molecule, and abstracting it is the first step of the process that makes most of the world's phenol.
Skeletal structure — isopropyl group at C-1
Structural Identity
- IUPAC Name(1-Methylethyl)benzene
- Common namesIsopropylbenzene, 2-phenylpropane
- Molecular FormulaC₉H₁₂
- Molecular Weight120.19 g/mol
- Hybridisationsp² ring, sp³ side-chain carbons
- Bond typeAromatic ring + isopropyl substituent
- Reactive siteTertiary benzylic C–H
- Key reactionAutoxidation to cumene hydroperoxide
- Peroxide formerYes — Class B, forms on air contact
- CAS Number98-82-8
- InChI KeyRWGFKTVRMDUZSP-UHFFFAOYSA-N
Product Specifications
Chelora supplies Cumene in standard and custom grades. Contact us for specification sheets tailored to your process.
| Chemical name | Cumene (isopropylbenzene) |
|---|---|
| CAS Number | 98-82-8 |
| Molecular formula | C₉H₁₂ |
| Molecular weight | 120.19 g/mol |
| Purity (min) | ≥ 99.50 wt% |
| Peroxides as CHP (max) | ≤ 5 ppm wt |
| Phenol (max) | ≤ 5 ppm wt |
| n-Propylbenzene (max) | ≤ 0.05 wt% |
| Ethylbenzene (max) | ≤ 0.05 wt% |
| Benzene (max) | ≤ 0.02 wt% |
| Butylbenzenes (max) | ≤ 0.05 wt% |
| Total sulfur (max) | ≤ 1.0 ppm wt |
| Chlorides (max) | ≤ 1.0 ppm wt |
| Water (max) | ≤ 200 ppm wt |
| Colour | ≤ 10 Pt-Co (Hazen) |
| Distillation range | 151.5 – 153.5 °C |
| Density | 0.860 – 0.864 g/cm³ at 20 °C |
| Flash point | 36 °C (closed cup) |
| Autoignition temperature | 424 °C |
| Flammable limits | 0.9 – 6.5% v/v in air |
| UN Number | UN 1918 |
| IMDG / ADR Class | Class 3 (Flammable Liquid), PG III |
Downstream Applications & Derivatives
Key derivative chains and industrial uses of Cumene.
Phenol & Acetone
Air oxidation to cumene hydroperoxide followed by acid-catalysed cleavage gives phenol and acetone together. This single route takes around 98% of world cumene and makes most of the world's phenol.
Bisphenol-A & Polycarbonate
Phenol condensed with acetone — both from the same cumene molecule — gives bisphenol-A, the monomer for polycarbonate sheet and optical media and for epoxy resin systems.
Phenolic Resins
Phenol with formaldehyde gives novolac and resol resins for plywood and engineered wood adhesives, foundry binders, laminates and friction materials.
Caprolactam & Nylon 6
The phenol route to cyclohexanone and on to caprolactam remains an important nylon 6 chain alongside the benzene-to-cyclohexane route.
MMA & Acrylics
Acetone co-product feeds the acetone cyanohydrin route to methyl methacrylate for PMMA sheet, and goes into solvents, pharmaceuticals and coatings.
α-Methylstyrene & Specialities
Alpha-methylstyrene, recovered as a phenol-plant co-product, is used in ABS heat-resistance modification, hydrocarbon resins and polymer additives.
Why source Cumene through Chelora Petrochem?
Verified Origin
Full origin certification and asset-backed supply chain documentation — no grey-market supply.
Grade Flexibility
Supplied to oxidation-unit specification with peroxide, phenol, sulfur and chloride content certified, and the impurity slate tailored to your catalyst system.
Full Documentation
CoA, SDS, UN transport docs, REACH compliance, and destination-market certificates with every shipment.
Logistics Support
Experienced in bulk aromatic liquid logistics — ISO tanks, road tankers, and drums with nitrogen blanketing where required, for Indian and international delivery.
Storage & Handling Guidelines
Always refer to the full SDS before handling. The following is a summary of key requirements.
- Store in a bunded, well-ventilated, dedicated area away from ignition sources, heat and direct sunlight.
- Treat cumene as a peroxide-forming chemical — minimise air in the headspace, date every container on receipt, and use stock first-in, first-out.
- Test for peroxide content before use on any container that has been open or stored beyond its recommended period; never distil or evaporate cumene to dryness.
- All electrical equipment in storage and transfer areas must be ATEX/IECEx rated for the applicable zone.
- Bond and earth tanks, tankers, drums and hoses before every transfer — cumene accumulates static readily.
- Keep away from strong oxidisers and acids, which both accelerate peroxide formation and can trigger violent decomposition of any peroxide present.
- Provide local exhaust ventilation at sampling and drumming points, and monitor personal exposure against the OEL.
- Keep foam, dry chemical or CO₂ media available for firefighting — water jets spread the burning liquid.
Hazard Summary
Classification: Flam. Liq. 3 (H226) · Carc. 2 (H351) · Asp. Tox. 1 (H304) · STOT SE 3 (H335) · Skin Irrit. 2 (H315) · Aquatic Chronic 2 (H411).
Peroxide formation: Cumene autoxidises in contact with air to cumene hydroperoxide, which is shock- and heat-sensitive and can decompose violently, especially if concentrated by evaporation or distillation. Date containers on receipt, limit headspace air, test for peroxides before use on aged stock, and never evaporate cumene to dryness.
Health: Classified Carc. 2 under CLP and placed in IARC Group 2B, possibly carcinogenic to humans. Aspiration into the lungs can cause chemical pneumonitis — never induce vomiting.
Exposure limits: ACGIH TLV 50 ppm 8-h TWA; OSHA PEL 50 ppm TWA with a skin notation. Confirm the limit in force in your jurisdiction.
Environment: Toxic to aquatic life with long-lasting effects. Bund all storage and prevent any release to drains, surface water or groundwater.
PPE minimum: Chemical splash goggles, nitrile or Viton gloves, flame-retardant antistatic clothing, and organic-vapour respiratory protection where ventilation cannot hold exposure below the limit.
Consult the full SDS for exposure limits, spill containment, emergency response, and disposal before any use.
Frequently Asked Questions
Technical and commercial questions about Cumene sourcing and specifications.
What is cumene used for?
Around 98% of cumene goes into the Hock process, which oxidises it to cumene hydroperoxide and cleaves that into phenol and acetone. Through phenol it reaches bisphenol-A and polycarbonate, epoxy resins, phenolic wood adhesives and laminates, and caprolactam for nylon 6. Through the acetone co-product it reaches methyl methacrylate, solvents and pharmaceuticals. Small volumes are used as a solvent and thinner.
How does the cumene process work?
Benzene is alkylated with propylene to give cumene. The cumene is then oxidised with air at moderate temperature to cumene hydroperoxide, and that hydroperoxide is cleaved with dilute sulfuric acid into phenol and acetone. The tertiary benzylic hydrogen on the isopropyl group is what makes the first oxidation step easy, and it is the reason cumene rather than another alkylbenzene is used.
Why are phenol and acetone prices linked?
Because the chemistry fixes the ratio. Every cumene molecule that goes through the process yields one phenol and one acetone, which works out at roughly 0.6 tonnes of acetone for every tonne of phenol. Producers cannot make one without the other, so when phenol demand runs ahead of acetone demand the acetone market goes long, and vice versa. Both markets move together as a result.
Why is cumene treated as a peroxide former?
The tertiary benzylic C–H that makes cumene useful also makes it reactive towards atmospheric oxygen. Cumene slowly autoxidises to cumene hydroperoxide on standing in contact with air. That peroxide is heat- and shock-sensitive and becomes dangerous when concentrated, which is why cumene containers are dated on receipt, kept with minimal headspace air, tested for peroxides before use if aged, and never distilled or evaporated to dryness.
What impurities matter to a phenol plant?
Peroxides already present in the feed upset the oxidation step's control. Phenol is an inhibitor of the oxidation reaction, so even a few ppm matters. Sulfur and chlorides affect catalyst and equipment. n-Propylbenzene and butylbenzenes oxidise to by-products that carry into the phenol and acetone and complicate purification. Specifications are tight on all of these.
What documentation does Chelora provide?
Every shipment includes a Certificate of Analysis covering purity, peroxides as CHP, phenol, n-propylbenzene, ethylbenzene, benzene, sulfur, chlorides, water, colour and distillation range; a Safety Data Sheet (GHS/REACH); UN 1918 Class 3 PG III transport documentation; peroxide-handling and container-dating guidance; an origin certificate; and any destination-market certificates required.
Request a quote or specification sheet
Talk to Chelora's sourcing team about Cumene grade, volume, logistics, documentation, and lead times. We respond within one business day.
