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Ethylene Oxide

EO · CAS 75-21-8

The foundational petrochemical building block behind ethylene glycols, ethoxylate surfactants and medical sterilization — handled under strict controlled-transport protocols throughout.

Chelora Chemicals supplies Ethylene Oxide to glycol, surfactant and specialty-chemical manufacturers worldwide, with full engineering and regulatory documentation on every consignment.

  • Ethylene glycol precursor
  • Ethoxylate & surfactant feedstock
  • Medical sterilant
  • Extremely flammable gas
  • Suspected carcinogen — strict exposure control required
  • UN 1040

Product identity

CAS Number
75-21-8
IUPAC name
Oxirane
Molecular formula
C₂H₄O
Molecular weight
44.05 g/mol
Boiling point
10.4 °C
Melting point
-112.5 °C
UN Number
UN 1040
HS Code
2910 10*

* Confirm the current HS classification, transport protocol and import regulatory status for your destination with your own regulatory affairs and logistics teams before ordering.

44.05g/mol molecular weight
10.4 °CBoiling point
0.882g/cm³ density (liquid)
UN 1040Transport classification
Product overview

What Ethylene Oxide is used for

Ethylene oxide (EO) is a colourless, extremely flammable gas at room temperature, with a boiling point of only 10.4 °C — it is handled and transported as a refrigerated or pressurised liquid in dedicated, specification-compliant equipment throughout the supply chain. Its three-membered oxirane ring makes it exceptionally reactive, the basis of its entire downstream chemistry.

EO's single largest use, accounting for an estimated three-quarters of global consumption, is as the feedstock for ethylene glycols — mono-, di- and triethylene glycol — which go on to make polyester fibre, PET resin and automotive antifreeze. The remainder feeds ethoxylates, ethanolamines and surfactants used in detergents, emulsifiers and dispersants, and polyethylene glycols (PEGs) used in cosmetics, pharmaceuticals and lubricants. In its pure gaseous form it is also the most widely used chemical sterilant for medical devices, accounting for roughly 70% of medical device sterilization worldwide, owing to its ability to penetrate packaging and sterilise at low temperature.

Where it sits in the petrochemical value chain

  • Ethylene Oxide (this product) the foundational building block, made by the catalytic oxidation of ethylene.
  • Mono/Di/Triethylene Glycol the direct downstream glycols used in polyester and antifreeze chemistry. See that page.
  • Purified Terephthalic Acid / Dimethyl Terephthalate the acid-side monomers that combine with MEG to form PET. See that page.

Handling character

Ethylene oxide is an extremely flammable, toxic, corrosive and suspected-carcinogenic gas requiring dedicated engineering controls at every stage. Full hazard detail is in the Safety section below.

Typical commercial specification
ParameterTypical value
AppearanceColourless liquefied gas
Assay99.8% min
Water contentWithin producer specification
AcidityWithin producer specification

Important: the figures above are indicative of commercial material and are offered for planning only. The batch certificate of analysis is the governing document.

Physical & chemical properties
PropertyValue
Physical stateColourless gas at room temp; liquid under refrigeration/pressure
Boiling point10.4 °C
Melting point-112.5 °C
Density (liquid)0.882 g/cm³
Flash point< -20 °C (extremely flammable)
Water solubilityFully miscible

Physical constants compiled from public reference data for CAS 75-21-8 and rounded for readability. Treat them as orientation, not as a specification — the SDS for your specific batch and shipment governs.

Applications

Where our customers put this feedstock to work

The reactive, three-membered-ring molecule behind the glycol, surfactant and sterilization industries.

Ethylene glycol production

Hydrolysed into mono-, di- and triethylene glycol feeding polyester, PET and antifreeze chemistry.

  • Polymer-grade specification
  • Dedicated pressurised/refrigerated supply
  • Technical desk review on request

Ethoxylates & surfactants

Reacted to form ethoxylates, ethanolamines and surfactants used in detergents, emulsifiers and dispersants.

  • Documented batch traceability
  • Contract & spot supply
  • Technical desk review on request

Medical device sterilization

Used as the most widely adopted low-temperature chemical sterilant for medical devices and packaging.

  • Electronic/sterilization-grade specification
  • Full analytical documentation available
  • Retained sample held against the lot

Polyethylene glycol (PEG)

Polymerised into PEGs used in cosmetics, pharmaceuticals and lubricant formulations.

  • Documented batch traceability
  • Technical desk review on request

Fumigant & fungicide chemistry

Used in smaller volumes as a fumigant and fungicide intermediate.

  • Research & process-scale quantities
  • Full documentation supplied

Contract & scheduled supply

Glycol and ethoxylate plants running continuous consumption are supported with scheduled, dedicated-equipment delivery.

  • Annual contracts with scheduled call-off
  • Price held across the contract period
  • Second source held in reserve
Buying from Chelora

How we supply Ethylene Oxide

Chelora Chemicals is a supplier and sourcing partner, not a manufacturer. Ethylene oxide's extreme flammability and refrigerated/pressurised handling requirement mean engineering review, transport protocol and regulatory documentation are central to every order — that shapes how we manage this line.

We place your order with whichever qualified producer best matches your required grade, your price point and your delivery window, and confirm your jurisdiction's import, transport and occupational-exposure requirements before booking.

We keep a second qualified source on this line, so a single-plant disruption never becomes your production problem.

  • Assay confirmed before we quote. Consistency matters to downstream glycol and ethoxylate quality.
  • UN 1040 dedicated transport engineered before booking. Pressurised/refrigerated equipment confirmed compliant for your route.
  • Carcinogenicity and flammability declarations filed correctly. Every shipment carries the correct hazard and regulatory declarations.
  • Scheduled call-off scheduling. We hold contracted tonnage and release it against your consumption calendar.
  • Batch traceability to the producing plant. Full chain of custody documentation on request.
  • Export machinery handled in-house. Classification, approved transport equipment, labelling, freight booking and customs paperwork are ours to manage.
Packing & logistics

Shipped the only way this product safely moves

Dedicated pressurised/refrigerated equipment only — no drum, bag or small-pack format exists for this product.

Pressurised ISO tank

Dedicated ISO tank container

Purpose-built pressurised tank containers rated and certified for UN 1040 ethylene oxide transport.

Rail / road tanker

Dedicated bulk tanker shipment

Dedicated rail or road tanker equipment for direct plant-to-plant bulk supply where pipeline connection is unavailable.

Engineering sign-off

Pre-shipment engineering review

Every shipment is preceded by an engineering and safety review of the receiving site's equipment and procedures.

FOB · CIF · CFR · DDP

Incoterms to suit you

Quoted on the Incoterm your purchasing team works to, with documentation filed before booking.

Scheduled release

Contracted call-off supply

We hold contracted tonnage and release it against your consumption calendar.

Pipeline supply

Direct pipeline connection

Where feasible, direct pipeline supply between adjacent producer and consumer sites can be arranged.

Safety, storage & handling

Extremely flammable & suspected carcinogen — strict exposure control required

Ethylene oxide's combination of extreme flammability, acute toxicity and carcinogenicity concern makes this one of the most tightly controlled products we supply. The summary below is orientation only — the safety data sheet supplied with your specific batch, and your jurisdiction's occupational exposure limits, are the authoritative documents.

GHS Signal word: Danger

Classified hazards

  • H220Extremely flammable gas.
  • H230May react explosively even in the absence of air.
  • H301Toxic if swallowed.
  • H314Causes severe skin burns and eye damage.
  • H331Toxic if inhaled.
  • H335/H336May cause respiratory irritation / drowsiness or dizziness.
  • H340May cause genetic defects.
  • H350May cause cancer.
  • H360FDMay damage fertility and the unborn child.
  • H372Causes damage to organs through prolonged or repeated exposure.

Classified as a Group 1 human carcinogen by IARC. Always read the SDS issued with your specific batch and shipment and follow your site's engineering controls, continuous gas monitoring and medical-surveillance requirements for this material.

Storage

Stored exclusively in dedicated, refrigerated or pressurised, inert-gas-blanketed vessels in bunded, access-controlled areas with continuous leak detection, away from all ignition sources and incompatible materials.

Handling

Handled exclusively via closed-transfer systems with continuous gas monitoring, explosion-proof equipment and dedicated emergency response procedures. Personnel require specialist training, respiratory and skin protection, and medical-surveillance programmes consistent with this material's carcinogenicity classification.

Transport

Shipped as UN 1040 exclusively via certified pressurised/refrigerated equipment. We confirm and document the engineering review, packing group, and exact classification for your specific shipment and destination before booking.

Quality assurance

Every batch, documented

We verify documentation and engineering compliance before dispatch so there are no surprises at your incoming-goods bench.

Specification & engineering review

Assay, transport equipment and receiving-site engineering confirmed against your process requirement before order placement.

Producer batch testing

The producing plant tests each batch against the agreed specification before release.

Documentation review

COA, SDS, carcinogenicity declaration and transport paperwork checked by our desk before the shipment is booked.

Traceable dispatch

Each shipment is traceable to its producing batch, with full chain-of-custody records on request.

Production background

How Ethylene Oxide is made

Ethylene oxide is produced industrially by the catalytic oxidation of ethylene over a silver catalyst, a long-established route in petrochemical chemistry, with production facilities typically integrated directly into ethylene glycol manufacturing to minimise the need to transport this high-hazard intermediate.

We do not publish operating process parameters here; this is background only. Full technical, safety and regulatory documentation accompanies every shipment, and any process-specific detail you need is best confirmed directly with our technical desk.

Quick reference
Chemical familyCyclic ether (oxirane) / epoxide
Reactive siteStrained three-membered oxirane ring
ReactivityRing-opens readily with water, alcohols and amines
Related compoundsEthylene (feedstock), Mono/Di/Triethylene Glycol (downstream)
Frequently asked

Ethylene Oxide, answered

What is Ethylene Oxide used for?
Ethylene oxide is used mainly to manufacture ethylene glycols (up to roughly 75% of global consumption), which go on to make polyester fibre, PET resin and antifreeze. It is also used to make ethoxylates, surfactants and ethanolamines for detergents, and polyethylene glycols for cosmetics and pharmaceuticals. It is also the most widely used chemical sterilant for medical devices, accounting for roughly 70% of medical sterilizations worldwide.
Is Ethylene Oxide hazardous?
Yes, significantly. It is an extremely flammable gas, a compressed gas, toxic if swallowed, causes severe skin burns and eye damage, toxic if inhaled, may cause respiratory irritation and drowsiness, is a suspected carcinogen and mutagen, may damage fertility or the unborn child, and causes damage to organs through prolonged or repeated exposure. It ships as UN 1040 under strict controlled-transport protocols, and every shipment carries full regulatory documentation.
How is Ethylene Oxide supplied and transported?
Given its extreme flammability and the need for refrigerated or pressurised containment, Ethylene Oxide is supplied exclusively via dedicated, specification-compliant pressurised/refrigerated transport and storage equipment, arranged directly between you and the producer's logistics team, with full engineering, safety and regulatory sign-off before any shipment moves.
What grade do you supply?
Polymer-grade and electronic-grade Ethylene Oxide to the specification your downstream glycol, ethoxylate or sterilization process requires. Tell us your end use and we will quote against the correct specification and transport protocol.
What packing do you offer?
Dedicated pressurised/refrigerated ISO tank and rail/road tanker shipment only, engineered and documented to UN 1040 requirements. We do not offer drum or small-pack formats for this product given its hazard profile.
Do you manufacture this yourself?
No - Chelora Chemicals is a supplier and sourcing partner, not a manufacturer. We place your order with whichever qualified producer fits your specification and timeline, and hold a second source in reserve.
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