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Cyclic Ether (Epoxide) · CAS 75-21-8

Ethylene Oxide

C2H4O Molar mass 44.05 g/mol

The three-membered cyclic ether supplied by Chelora Chemicals — known in the trade as EO, the single most important building block for ethylene glycols, ethoxylate surfactants, glycol ethers and ethanolamines — exported from Indonesia as a refrigerated or pressurised liquefied gas in dedicated ISO tanks with full batch documentation on every shipment.

Identification Sheet REP.
IUPAC nameOxirane
CAS number75-21-8
Molecular formulaC₂H₄O
Molar mass44.05 g/mol
AppearanceColourless gas / liquefied gas, sweet ether-like odour
Common synonymsEthylene Oxide, Oxirane, EO
Melting Point−111 °Clit.
Boiling Point10.7 °Cat 1 atm — a gas at ambient conditions
Specific Gravity0.882liquid, at 10 °C
Flash PointBelow −20 °Cextremely flammable gas
AppearanceColourless gas, liquefied under refrigeration/pressuresweet, ether-like odour
Purity Offered99.7%+polymer/surfactant grade, liquefied gas
01 / PRODUCT DOSSIER

What Ethylene Oxide is, and why buyers source it

A working overview of the compound's chemistry, its role as the most reactive small-ring epoxide produced at industrial scale, and the grade Chelora Chemicals keeps in regular supply.

Ethylene Oxide is the simplest cyclic ether: a three-membered ring built from two carbons and one oxygen, under enough ring strain that the ring opens readily when attacked by almost any nucleophile — water, alcohols, amines, carboxylic acids. That single property, ring-opening reactivity, is the basis of essentially the entire ethylene oxide derivatives industry, from glycols to surfactants to solvents.

At room temperature and pressure it is a colourless, extremely flammable gas with a faintly sweet, ether-like odour, and is shipped and stored as a refrigerated or pressurised liquefied gas. It is fully miscible with water, where it reacts only slowly without a catalyst, and far more reactive toward the catalysed or acid/base-promoted ring-opening reactions used in industrial manufacture.

Where it fits in the synthesis chain

Ethylene Oxide's largest use by far is hydration to monoethylene glycol and the higher glycols (diethylene glycol, triethylene glycol), the feedstock for PET polyester and antifreeze/coolant fluids. The remainder is consumed in making ethoxylate surfactants (reacting EO with a fatty alcohol, acid or amine in a controlled chain-length reaction), glycol ethers, ethanolamines, and polyether polyols for polyurethane foam. A small, well-established use is as a gaseous sterilant for single-use medical devices and some spices, where its ability to penetrate packaging and kill micro-organisms at room temperature is uniquely useful.

Grade we supply

Chelora Chemicals offers Ethylene Oxide in a single polymer/surfactant grade (99.7%+ assay, low in aldehyde and moisture) suitable for monoethylene glycol, ethoxylate and polyol manufacture. It is supplied as a refrigerated or pressurised liquefied gas in dedicated ISO tanks, with a batch-wise certificate of analysis.

02 / MANUFACTURING ROUTE

How Ethylene Oxide is made

An overview of the production route for orientation purposes. Our manufacturing partners' own process parameters and in-process controls are proprietary and are not disclosed beyond what is needed to interpret the certificate of analysis.

Ethylene Oxide is manufactured by the direct catalytic oxidation of ethylene with oxygen over a silver-based catalyst: 2 C₂H₄ + O₂ → 2 C₂H₄O, run in a multi-tubular reactor at moderate temperature and pressure with careful dilution to keep the reaction mixture outside the flammable range. The reaction is highly exothermic and selective but not perfectly so, since a competing combustion side-reaction to carbon dioxide and water is always present and is minimised through catalyst design and process control.

Why silver-catalysed direct oxidation is universal

Direct oxidation of ethylene over a silver catalyst has been the standard commercial route since it displaced the older chlorohydrin process decades ago, because it avoids chlorinated by-products entirely and, with modern high-selectivity catalysts, converts ethylene to ethylene oxide at very high efficiency, making it the overwhelming choice at every ethylene oxide plant built today.

03 / APPLICATIONS

Industries and processes that use it

Ethylene Oxide is consumed overwhelmingly in glycol manufacture, with significant further demand from surfactant, solvent and polyol production, and a smaller specialised role as a sterilant gas. The fields below account for most of the demand we see through our export desk.

Field 01

Monoethylene Glycol (MEG) Feedstock

Hydrated with water to monoethylene glycol, the single largest downstream use, feeding PET polyester and antifreeze/coolant manufacture.

Field 02

Ethoxylate Surfactant Manufacture

Reacted in a controlled chain-growth reaction with fatty alcohols, acids or amines to build nonionic surfactants used across detergent and personal-care formulation.

Field 03

Glycol Ether & Ethanolamine Chain

Reacted with alcohols to make glycol ether solvents, and with ammonia to make mono-, di- and triethanolamine for a wide range of industrial uses.

Field 04

Polyurethane Polyol Chain

Used as a comonomer with propylene oxide in polyether polyol manufacture for flexible and rigid polyurethane foam.

04 / REACTION CHEMISTRY

How the molecule is typically carried forward

The strained three-membered ring's readiness to open under nucleophilic attack governs almost all of this molecule's further reaction chemistry. Reaction classes below account for most of the ways Ethylene Oxide is converted into a finished product or intermediate.

Hydration (to Glycols)

Water opens the strained ring to give monoethylene glycol, with further reaction of EO with the glycol product giving the higher di- and triethylene glycols as co-products.

Alkoxylation (Ethoxylation)

A fatty alcohol, acid or amine opens the ring under base catalysis, and repeated ring-opening builds a defined-length polyether (ethoxylate) chain.

Amination (to Ethanolamines)

Ammonia opens the ring to give mono-, di- and triethanolamine in a controlled ratio depending on reaction stoichiometry.

Ring-Opening Copolymerisation (to Polyols)

EO copolymerises with propylene oxide onto a polyol initiator, building the polyether backbone used in polyurethane foam formulation.

05 / RELATED BUILDING BLOCKS

Ethylene Oxide against other amines we supply

Buyers sourcing Ethylene Oxide for glycol or surfactant manufacture most often need Mono Ethylene Glycol, its single largest downstream product. A quick reference to what else is on our regular supply list.

ProductCAS NumberCategoryNotes
Ethylene Oxide75-21-8Cyclic ether (epoxide)The product on this page — the common feedstock for glycols, ethoxylates and ethanolamines.
Mono Ethylene Glycol107-21-1GlycolThe single largest downstream hydration product — see its product page.
Para-Xylene106-42-3PET co-feedstockThe aromatic co-feedstock for PET polyester, alongside MEG — see its product page.
Mixed Xylenes1330-20-7C8 aromatic isomer blendA related high-volume petrochemical intermediate — see its product page.

Exact physical constants and purity specifications are confirmed per batch on the certificate of analysis — treat the notes above as a sourcing guide, not a specification sheet, for products other than Ethylene Oxide.

06 / HAZARD & HANDLING

Safety classification at a glance

Based on GHS classification as commonly listed for this substance. This is a summary for orientation only — always work from the current safety data sheet supplied with your specific batch.

H220

Extremely flammable gas.

H331

Toxic if inhaled.

H340

May cause genetic defects.

H350

May cause cancer.

PPE Standard

Full gas-handling PPE including appropriate respiratory protection, chemical-resistant gloves and goggles are mandatory for any direct handling.

Pressurised Handling

Shipped as a liquefied gas under refrigeration or pressure in dedicated ISO tanks; only trained personnel with proper equipment should transfer it.

Self-Polymerisation Hazard

Can self-polymerise exothermically if contaminated with certain catalysts, acids, bases or metals — dedicated, clean equipment is essential.

Signal word

Danger — GHS02 flammable, GHS06 toxic and GHS08 health-hazard pictograms apply.

This compound is an extremely flammable gas that is toxic if inhaled, may cause genetic defects, and may cause cancer. It is a recognised human carcinogen and must be handled only by trained personnel using dedicated, properly rated equipment, full respiratory protection and strict control of ignition sources and contamination. Full first-aid, storage, spill and PPE guidance is in the MSDS issued with every shipment, and must be read in full and followed without exception before this material is handled.

07 / STORAGE & SHELF LIFE

Keeping it on spec between delivery and use

General storage guidance for this grade. Site-specific storage rules, segregation requirements and re-test intervals should follow your own EHS procedures and the MSDS issued with your batch.

Storage ConditionRefrigerated or pressurised liquefied gas
ContainerDedicated, inerted pressure vessel / ISO tank
Typical Shelf LifeBy arrangement, inhibitor/purity dependent
Keep Away FromHeat, ignition sources, acids, bases, metals, catalysts
Beyond Shelf LifeRe-assay before use

Store as a refrigerated or pressurised liquefied gas in dedicated, properly rated and inerted equipment, isolated from heat sources, ignition sources, acids, bases, metal contaminants and polymerisation catalysts. Only personnel trained in liquefied-gas and EO-specific handling procedures should work with this material, following the detailed storage and transfer protocol in the MSDS. Re-check purity and moisture content before use if a batch is held for an extended period.

08 / PACKING & EXPORT

How it ships from Indonesia

Standard packing and export terms for this product. Confirm exact figures against your order — they vary slightly by destination and quantity.

Standard PackingPressurised/refrigerated ISO tank
Bulk PackingDedicated gas carrier by arrangement
Min. OrderBy arrangement
Lead Time3 – 5 weeks
Export TermsFOB · CFR · CIF
09 / QUALITY & DOCUMENTATION

What travels with every batch

Specification is agreed before the purchase order, not discovered on arrival. Every shipment of Ethylene Oxide leaves with a documented, checkable paper trail.

Doc 01

Certificate of Analysis

Batch-wise assay (by titration/GC), colour and relevant physical constants, issued against the agreed specification so your QC team can check it, not just file it.

Doc 02

Safety Data Sheet

GHS-format SDS in English covering hazard classification, handling, storage, first-aid and spill response for the exact grade of Ethylene Oxide shipped.

Doc 03

Technical Data Sheet

Reference physical and chemical properties, recommended storage and typical applications, for internal circulation to your process or R&D teams.

Doc 04

Certificate of Origin

Confirms Indonesian origin for customs clearance and any preferential-duty claim at your destination port.

Doc 05

Dangerous Goods Declaration

UN packing group, classification and shipper's declaration prepared ahead of loading so documentation never holds up customs.

Doc 06

Third-Party Inspection

Independent pre-shipment inspection and re-sampling can be arranged on request, at your cost, for buyers who require it as a matter of policy.

10 / FAQ

Frequently asked questions

What buyers most often ask our sales desk about this grade.

01What is Ethylene Oxide used for?+
Overwhelmingly as the feedstock for monoethylene glycol, used in PET polyester and antifreeze; it is also used to make ethoxylate surfactants, glycol ethers, ethanolamines and polyurethane polyols, and in a specialised role as a gas sterilant.
02What is the CAS number of Ethylene Oxide?+
Its CAS Registry Number is 75-21-8, with molecular formula C₂H₄O and a molar mass of 44.05 g/mol.
03How is Ethylene Oxide made?+
By direct catalytic oxidation of ethylene with oxygen over a silver-based catalyst, the standard commercial route used at essentially every plant built today.
04What grade does Chelora Chemicals supply?+
We supply a single polymer/surfactant grade (99.7%+ assay, low in aldehyde and moisture) suitable for monoethylene glycol, ethoxylate and polyol manufacture, supplied as a refrigerated or pressurised liquefied gas with a certificate of analysis.
05Is Ethylene Oxide hazardous?+
Yes, significantly. It is an extremely flammable gas that is toxic if inhaled, may cause genetic defects, and is a recognised human carcinogen. It must only be handled by trained personnel using the dedicated equipment and strict procedures specified in the MSDS supplied with each shipment.
06Why is Ethylene Oxide shipped as a liquefied gas rather than a liquid like other feedstocks?+
Its boiling point of 10.7 °C means it is a gas at ordinary ambient temperature, so it must be kept either refrigerated below that temperature or under pressure to stay in liquid form for practical storage, transfer and transport in dedicated ISO tanks.
07What packing options are available?+
Ethylene Oxide ships as a refrigerated or pressurised liquefied gas in dedicated ISO tanks; dedicated gas carrier shipment can be arranged for larger volumes. Contact our desk to discuss packaging and logistics for your specific requirement.
08How long does delivery take?+
Given the specialised logistics required for a liquefied, highly reactive gas, typical lead time is three to five weeks plus transit. A firm date and logistics plan is confirmed in the written quotation.
09Can I get a sample before placing a bulk order?+
Given the specialised handling this material requires, sample logistics are arranged case by case — contact our desk to discuss what is practical for your location and application.
10Do you supply Mono Ethylene Glycol as well?+
Yes, we also supply Mono Ethylene Glycol, the single largest downstream product made by hydrating Ethylene Oxide, for buyers who need the glycol rather than the oxide itself.
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