# Nitrocellulose with water with not less than 25 percent water, by mass — Postal shipping restrictions by item category

For Nitrocellulose with water with not less than 25 percent water, by mass, carrier is USPS; restriction type is restricted; scope is domestic mail: surface only (air prohibited); conditions is Hazard class 4.1, UN2555, packing group II; domestic mail air: Prohibited; domestic mail surface: 4A, recorded from its source on 2026-08-10.

- **Item category:** Nitrocellulose with water with not less than 25 percent water, by mass _(verified: appears in the quote below)_
- **Carrier:** USPS _(our reading, not quoted from the source)_
- **Restriction type:** restricted _(our reading, not quoted from the source)_
- **Scope:** domestic mail: surface only (air prohibited) _(our reading, not quoted from the source)_
- **Conditions:** Hazard class 4.1, UN2555, packing group II; domestic mail air: Prohibited; domestic mail surface: 4A _(verified: appears in the quote below)_

## What the source says

> Nitrocellulose with water with not less than 25 percent water, by mass 4.1 UN2555 II Prohibited 4A

## Source

- https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.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/).