# Ethylene oxide

A reactive, toxic gas made by oxidising ethylene over silver; the gateway to glycols for polyester, surfactants, ethanolamines and sterilisation.

Source page: https://www.materialinsights.org/chemicals/ethylene_oxide/

Commodity chemicals · Derivatives & intermediates · No. 36

- Single chemical
- Feedstock: Oil, gas or coal
- about 33-35 Mt produced a year (2025, indicative: about 40 Mt capacity x about 85%)
- 1.9 t CO₂e per t
- HS 291010
 Commodity chemicals · Derivatives & intermediates · Foundation · Matter

A gas that can burn with no air at all is also the chemical that sterilises your hospital's syringes.

Chart: Illustration: Ethylene oxide

##### Where it comes from

Chart: Map of where it comes from

Ethylene and pure oxygen circulate over silver catalyst at 220-280 C. Modern catalysts are 85-90% selective; the rest of the ethylene burns to CO2 and water.

##### Three things to know

1. About 70% of ethylene oxide never leaves the site as EO; it is turned into glycols for polyester straight away.
2. EO can burn in mixtures from 3% to 100% in air, so tanks are blanketed with nitrogen and kept cold.
3. US rules from 2024 aim to cut EO emissions at commercial sterilisers by about 90%.

##### The journey

1. 1 **Ethylene, oxygen**0.75 t ethylene, 0.7 t oxygen
2. 2 **Silver catalyst**Oxidised at 220-280 C
3. 3 **CO2 removal**Carbonate wash strips near-pure CO2
4. 4 **Derivative unit**Most hydrated straight into glycols
5. 5 **Products**Polyester glycols, detergents, amines, sterilants
 Covered in [How a chemical process works: reactions, separations, catalysts and flowsheetsChemicals](https://www.materialinsights.org/learn/chemicals/how-chemical-processes-work/)[From building blocks to plastics, fibres and detergentsChemicals](https://www.materialinsights.org/learn/chemicals/building-blocks-to-polymers/)[Scale, capacity and feedstock: which chemical plants get builtChemicals](https://www.materialinsights.org/learn/chemicals/scale-capacity-feedstock/)[Soaps, detergents and agrochemicalsChemicals](https://www.materialinsights.org/learn/chemicals/soaps-detergents-agrochemicals/)[Biorefineries and platform chemicalsChemicals](https://www.materialinsights.org/learn/chemicals/biorefineries-platform-chemicals/)

##### Go deeper pick a tab to open it in full

## Other sections

- [Overview](https://www.materialinsights.org/chemicals/ethylene_oxide/overview/index.md)
- [Correlation](https://www.materialinsights.org/chemicals/ethylene_oxide/correlation/index.md)
- [Production route](https://www.materialinsights.org/chemicals/ethylene_oxide/routes/index.md)
- [Production](https://www.materialinsights.org/chemicals/ethylene_oxide/production/index.md)
- [Feedstocks](https://www.materialinsights.org/chemicals/ethylene_oxide/feedstocks/index.md)
- [Cycles](https://www.materialinsights.org/chemicals/ethylene_oxide/cycles/index.md)
- [Trading](https://www.materialinsights.org/chemicals/ethylene_oxide/trading/index.md)
- [Movement](https://www.materialinsights.org/chemicals/ethylene_oxide/movement/index.md)
- [Regulation](https://www.materialinsights.org/chemicals/ethylene_oxide/regulation/index.md)
- [Characteristics](https://www.materialinsights.org/chemicals/ethylene_oxide/characteristics/index.md)
- [Emissions](https://www.materialinsights.org/chemicals/ethylene_oxide/emissions/index.md)
- [Relationships](https://www.materialinsights.org/chemicals/ethylene_oxide/links/index.md)