# Flammable solids — Postal shipping restrictions by item category

For Flammable solids, carrier is Royal Mail Wholesale (Access customers); restriction type is prohibited; scope is UK; conditions is Solid materials liable to cause fire by friction, absorption of water, spontaneous chemical changes or retained heat, e.g. adhesives, calcium carbide, cellulose nitrate products, fire lighters, matches, metallic magnesium, phosphorous, potassium, sodium, zinc powder, recorded from its source on 2026-08-10.

- **Item category:** Flammable solids _(verified: appears in the quote below)_
- **Carrier:** Royal Mail Wholesale (Access customers) _(our reading, not quoted from the source)_
- **Restriction type:** prohibited _(our reading, not quoted from the source)_
- **Scope:** UK _(our reading, not quoted from the source)_
- **Conditions:** Solid materials liable to cause fire by friction, absorption of water, spontaneous chemical changes or retained heat, e.g. adhesives, calcium carbide, cellulose nitrate products, fire lighters, matches, metallic magnesium, phosphorous, potassium, sodium, zinc powder. _(verified: appears in the quote below)_

## What the source says

> Flammable solids Solid materials which are liable to cause fire by friction, absorption of water, spontaneous chemical changes or retained heat from manufacturing or processing, or Prohibited item* Detailed information which can be readily ignited and burn vigorously e.g.

## Source

- https://www.royalmailwholesale.com/mint-project/uploads/233157117.pdf

Last verified: 2026-08-10. Review by: 2027-08-10.
Part of [Postal shipping restrictions by item category](https://referencesource.org/shipping-restrictions-by-class/).