# Propylene oxide

A reactive three-carbon epoxide made from propylene, used mostly to make polyols for polyurethane foam and propylene glycol.

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

Commodity chemicals · Derivatives & intermediates · No. 38

- Single chemical
- Feedstock: Oil, gas or coal
- about 12 Mt produced a year (2025, indicative: about 16 Mt capacity x about 75%)
- 2.5 t CO₂e per t
- HS 291020
 Commodity chemicals · Derivatives & intermediates · Foundation · Matter

The foam in your mattress, sofa and car seat starts with a volatile liquid that boils at 34 C.

Chart: Illustration: Propylene oxide

##### Where it comes from

Chart: Map of where it comes from

Propylene is oxidised using chlorine, an organic hydroperoxide that leaves styrene or tert-butanol behind, or hydrogen peroxide. The peroxide route gives water as its only by-product.

##### Three things to know

1. Unlike its ethylene cousin, PO cannot be made by simple air oxidation at scale, so every route needs a costly oxidant or makes a by-product.
2. China's capacity was heading for about 9.3 Mt a year by end-2025, after 1.54 Mt of new units from June 2025.
3. The old chlorohydrin route uses about 1.4 t of chlorine per tonne and makes about 40 t of salty wastewater.

##### The journey

1. 1 **Propylene**0.75-0.8 t per tonne PO
2. 2 **Oxidant**Chlorine, hydroperoxide or hydrogen peroxide
3. 3 **Epoxidation**HPPO is over 95% selective
4. 4 **Polyols**Made next door, since PO ships badly
5. 5 **Polyurethane**Polyol plus MDI or TDI makes foam
 Covered in [From building blocks to plastics, fibres and detergentsChemicals](https://www.materialinsights.org/learn/chemicals/building-blocks-to-polymers/)

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

## Other sections

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