# Hydrochloric acid (UN1789) — Postal shipping restrictions by item category

For Hydrochloric acid (UN1789), carrier is USPS; restriction type is restricted; scope is domestic mail via air or surface transportation; conditions is Acceptable only in solutions not exceeding 10% acid that qualify as Limited Quantity air or surface; Packaging Instruction 8A must be followed, recorded from its source on 2026-08-04.

- **Item category:** Hydrochloric acid (UN1789)
- **Carrier:** USPS _(our reading, not quoted from the source)_
- **Restriction type:** restricted _(our reading, not quoted from the source)_
- **Scope:** domestic mail via air or surface transportation _(our reading, not quoted from the source)_
- **Conditions:** Acceptable only in solutions not exceeding 10% acid that qualify as Limited Quantity air or surface; Packaging Instruction 8A must be followed _(unconfirmed — we could not tie this to the quote below)_

## What the source says

> Hydrochloric Acid (UN1789): Acceptable only in solutions not exceeding 10 percent acid that qualify as Limited Quantity air or Limited Quantity surface material.

## Source

- https://pe.usps.com/text/pub52/pub52c3_027.htm

Last verified: 2026-08-04. Review by: 2027-08-04.
Part of [Postal shipping restrictions by item category](https://referencesource.org/shipping-restrictions-by-class/).