# Propylene oxide: Characteristics

Why water traces ruin a polyol

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

Polyol producers need high-purity PO with very low aldehydes and water, because impurities affect polyol colour, odour and functionality. Its low boiling point and flammability drive logistics.

#### Properties that matter commercially

| Property | Value / specification | Why it matters | Source |
|---|---|---|---|
| **Purity** | at least 99.97% PO (indicative) | Polyol quality and catalyst life. | industry standard (indicative) |
| **Boiling point** | 34°C | Volatile; must be stored cool and pressurised with nitrogen. | standard physical data |
| **Water and aldehyde content** | water under about 100 ppm (indicative) | Water creates unwanted diols in polyols. | industry standard (indicative) |

#### Commercial grades

- Polymer/polyol grade PO
- Propylene glycol USP (food and pharma) and industrial grades
- Bio-PG (from glycerine)

## Other sections

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