# Ammonia solution, relative density less than 0.880 at 15° C in water, with more than 35 percent but not more than 50 percent ammonia · USPS — Mailing and air-carriage restrictions by item category

For Ammonia solution, relative density less than 0.880 at 15° C in water, with more than 35 percent but not more than 50 percent ammonia · USPS, item category is Ammonia solution, relative density less than 0.880 at 15° C in water, with more than 35 percent but not more than 50 percent ammonia; carrier is USPS; restriction type is prohibited; scope is domestic mail (air and surface); conditions is Hazard class 2.2, UN2073, packing group n/a; domestic mail air: Prohibited; domestic mail surface: Prohibited, recorded from its source on 2026-08-30.

- **Item category:** Ammonia solution, relative density less than 0.880 at 15° C in water, with more than 35 percent but not more than 50 percent ammonia _(verified: appears in the quote below)_
- **Carrier:** USPS _(our reading, not quoted from the source)_
- **Restriction type:** prohibited _(our reading, not quoted from the source)_
- **Scope:** domestic mail (air and surface) _(our reading, not quoted from the source)_
- **Conditions:** Hazard class 2.2, UN2073, packing group n/a; domestic mail air: Prohibited; domestic mail surface: Prohibited

## What the source says

> Ammonia solution, relative density less than 0.880 at 15° C in water, with more than 35 percent but not more than 50 percent ammonia 2.2 UN2073 n/a Prohibited Prohibited

## Source

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

Last verified: 2026-08-30. Review by: 2027-08-30.
Part of [Mailing and air-carriage restrictions by item category](https://referencesource.org/shipping-restrictions-by-class/).