# Ethylene oxide: Characteristics

The strained ring that makes it useful and dangerous

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

What this tab covers The physical and chemical properties that set its grade, price and uses, with the commercial grades and the standards that define them.

EO's commercial value comes from its strained three-membered ring, which opens easily with water, alcohols and amines. The same reactivity makes it toxic and explosive, which governs storage, logistics and pricing.

#### Properties that matter commercially

| Property | Value / specification | Why it matters | Source |
|---|---|---|---|
| **Purity** | purified EO at least 99.9% | Ethoxylation and pharma uses need low aldehydes and water. | industry standard (indicative) |
| **Boiling point** | 10.7°C | Stored refrigerated as liquid. | standard physical data |
| **Flammability range** | 3% to 100% in air | Can burn without air; needs nitrogen blanketing. | standard safety data |

#### Commercial grades

- Purified EO (99.9%)
- Sterilisation-grade EO blends (with CO2 or nitrogen)
- Bio-EO (from bio-ethanol, India Glycols)

## Other sections

- [Summary](https://www.materialinsights.org/chemicals/ethylene_oxide/index.md)
- [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)
- [Emissions](https://www.materialinsights.org/chemicals/ethylene_oxide/emissions/index.md)
- [Relationships](https://www.materialinsights.org/chemicals/ethylene_oxide/links/index.md)