Benzene
The parent aromatic. A clear, volatile liquid hydrocarbon and the entry point to the styrene, phenol, nylon and aniline chains.
Molecular Structure
What is Benzene?
Benzene is the simplest aromatic hydrocarbon — six sp²-hybridised carbons in a planar ring, each carrying one hydrogen, with six π electrons delocalised evenly around the ring.
That delocalisation is worth roughly 150 kJ/mol of resonance stabilisation, and it is why benzene behaves nothing like an ordinary alkene. All six carbon–carbon bonds are identical at 1.39 Å, and the ring resists addition reactions that would destroy aromaticity, undergoing electrophilic aromatic substitution instead.
Commercially that reactivity is exploited through alkylation, hydrogenation and nitration. Around half of world benzene demand goes to ethylbenzene for styrene, with cumene, cyclohexane, nitrobenzene and linear alkylbenzene taking most of the remainder.
Chelora sources benzene from catalytic reformate and pyrolysis gasoline, recovered by sulfolane extractive distillation to ≥99.9 wt% with thiophene and total sulfur held below 1 ppm. Nitration and industrial grades available in ISO tanks, road tankers and drums.
Quick Reference
Key Physical & Chemical Properties
Structure & Bonding
Benzene's chemistry is defined by the aromatic sextet — six π electrons spread over a planar six-carbon ring, giving bonds of equal length and a strong preference for substitution over addition.
Skeletal structure — sp² carbons, delocalised π system
Structural Identity
- IUPAC NameBenzene
- Molecular FormulaC₆H₆
- Molecular Weight78.11 g/mol
- Hybridisationsp² (all six carbons)
- Bond typeAromatic — delocalised π sextet
- C–C bond length1.39 Å (all six equal)
- GeometryPlanar regular hexagon, D₆ₕ
- Resonance energy≈ 150 kJ/mol
- CAS Number71-43-2
- InChI KeyUHOVQNZJYSORNB-UHFFFAOYSA-N
Product Specifications
Chelora supplies Benzene in standard and custom grades. Contact us for specification sheets tailored to your process.
| Chemical name | Benzene |
|---|---|
| CAS Number | 71-43-2 |
| Molecular formula | C₆H₆ |
| Molecular weight | 78.11 g/mol |
| Purity (nitration grade) | ≥ 99.90 wt% |
| Purity (industrial grade) | ≥ 99.50 wt% |
| Crystallising point | ≥ 5.45 °C |
| Non-aromatics (max) | ≤ 0.10 wt% |
| Toluene (max) | ≤ 0.05 wt% |
| Thiophene (max) | ≤ 1.0 ppm wt |
| Total sulfur (max) | ≤ 1.0 ppm wt |
| Water (max) | ≤ 300 ppm wt |
| Colour | ≤ 20 Pt-Co (Hazen) |
| Acid wash colour | ≤ No. 2 |
| Distillation range | ≤ 1.0 °C, including 80.1 °C |
| Density | 0.8765 g/cm³ at 20 °C |
| Flash point | −11 °C (closed cup) |
| Autoignition temperature | 498 °C |
| Flammable limits | 1.2 – 7.8% v/v in air |
| UN Number | UN 1114 |
| IMDG / ADR Class | Class 3 (Flammable Liquid), PG II |
Downstream Applications & Derivatives
Key derivative chains and industrial uses of Benzene.
Ethylbenzene & Styrene
Friedel–Crafts alkylation with ethylene gives ethylbenzene, dehydrogenated to styrene — the route to polystyrene, EPS, ABS and SBR latex. This is the single largest benzene outlet worldwide.
Cumene → Phenol & Acetone
Alkylation with propylene gives cumene; the Hock process then cleaves cumene hydroperoxide into phenol and acetone, feeding bisphenol-A, polycarbonate, epoxy and phenolic resins.
Cyclohexane → Nylon
Hydrogenation to cyclohexane, then oxidation to KA oil and onward to caprolactam and adipic acid — the nylon 6 and nylon 6,6 chain for textile fibre and engineering plastics.
Aniline & MDI
Nitration to nitrobenzene and hydrogenation to aniline, then phosgenation to MDI for rigid polyurethane insulation, alongside rubber antioxidants and dye intermediates.
Linear Alkylbenzene
Alkylation with linear C₁₀–C₁₃ olefins gives LAB, sulfonated to LAS — the primary anionic surfactant in household and industrial detergents.
Chlorobenzene & Maleic Anhydride
Chlorination, sulfonation and partial oxidation routes give chlorobenzene, benzenesulfonic acid, maleic anhydride and hydroquinone for agrochemical, dye and pharmaceutical intermediates.
Why source Benzene through Chelora Petrochem?
Verified Origin
Full origin certification and asset-backed supply chain documentation — no grey-market supply.
Grade Flexibility
Nitration grade and industrial grade available. Sulfur, thiophene and non-aromatic specifications can be tightened to protect your downstream catalyst.
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.
- Handle in closed systems with vapour recovery, and use vapour balancing on all loading and unloading.
- All electrical equipment in storage and transfer areas must be ATEX/IECEx rated for the applicable zone.
- Bond and earth every tank, tanker, drum and hose before transfer begins — benzene accumulates static readily.
- Maintain a nitrogen blanket on bulk storage tanks to keep the headspace out of the flammable range.
- Run personal and area exposure monitoring against the applicable benzene occupational exposure limit, and keep records.
- Operate a written exposure-control plan with medical surveillance for personnel who work with benzene regularly.
- Keep away from strong oxidisers, acids and halogens; store below 30 °C in a dedicated, bunded area.
- Keep foam, dry chemical or CO₂ media available for firefighting — water jets spread the burning liquid.
Hazard Summary
Classification: Flam. Liq. 2 (H225) · Carc. 1A (H350) · Muta. 1B (H340) · STOT RE 1 (H372) · Asp. Tox. 1 (H304) · Skin and Eye Irrit. 2.
Carcinogenicity: Benzene is a confirmed human carcinogen (IARC Group 1), causally linked to acute myeloid leukaemia. No safe exposure threshold has been established, so exposure must be reduced to the lowest level reasonably practicable.
Exposure limits: ACGIH TLV 0.5 ppm 8-h TWA with a 2.5 ppm STEL and skin notation; OSHA PEL 1 ppm TWA / 5 ppm STEL. The EU binding limit steps down to 0.2 ppm from April 2026. Confirm the limit in force in your jurisdiction.
Flammability: Flash point −11 °C — benzene gives an ignitable vapour mixture at ordinary ambient temperature. Vapour is heavier than air and can travel to a distant ignition source.
PPE minimum: Chemical splash goggles, nitrile or Viton gloves (benzene permeates many elastomers), flame-retardant antistatic clothing, and supplied-air respiratory protection for any task that may exceed the exposure 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 Benzene sourcing and specifications.
What is benzene used for?
Roughly half of global benzene goes to ethylbenzene and on to styrene for polystyrene, EPS and ABS. The balance splits between cumene for phenol, acetone and bisphenol-A; cyclohexane for nylon 6 and nylon 6,6; nitrobenzene for aniline and MDI; and linear alkylbenzene for detergent surfactants, with smaller chlorobenzene and maleic anhydride outlets.
Why doesn't benzene react like an alkene?
Benzene's six π electrons are delocalised over all six carbons rather than localised in three double bonds, which is worth about 150 kJ/mol of resonance stabilisation. An addition reaction would destroy that aromatic system, so benzene undergoes electrophilic aromatic substitution instead — alkylation, nitration, sulfonation and halogenation — regenerating the ring each time. All six C–C bonds measure 1.39 Å, between a single and a double bond.
How is benzene produced?
The main sources are catalytic reforming of naphtha, pyrolysis gasoline from steam crackers, toluene hydrodealkylation, and toluene disproportionation. Because benzene boils close to non-aromatic C₆ hydrocarbons, it is recovered by extractive distillation or liquid–liquid extraction, most commonly with sulfolane.
What is nitration-grade benzene?
Nitration grade is the highest commercial purity, typically ≥99.9 wt% with a crystallising point of at least 5.45 °C and thiophene and total sulfur each below 1 ppm. The crystallising point is used as a quick purity check, and the sulfur limits matter because sulfur poisons the catalysts used in alkylation and hydrogenation downstream.
Is benzene carcinogenic, and how must it be handled?
Yes. Benzene is classified Carc. 1A under CLP and IARC Group 1, with a causal link to acute myeloid leukaemia. Handling requires closed transfer, vapour recovery, exposure monitoring against the local limit, medical surveillance for regularly exposed workers, and appropriate respiratory protection — in addition to the flammability controls needed for a liquid with a −11 °C flash point. Always work to the full SDS and your national regulations.
What documentation does Chelora provide?
Every shipment includes a Certificate of Analysis covering purity, crystallising point, thiophene, total sulfur, non-aromatics, water and colour; a Safety Data Sheet (GHS/REACH); UN 1114 Class 3 PG II transport documentation; an origin certificate; and any destination-market certificates required.
Request a quote or specification sheet
Talk to Chelora's sourcing team about Benzene grade, volume, logistics, documentation, and lead times. We respond within one business day.
