# Acetic acid (UN2790) — Postal shipping restrictions by item category

For Acetic acid (UN2790), carrier is USPS; restriction type is restricted; scope is domestic mail via air or surface transportation; conditions is Mailable if meets Limited Quantity requirements, contains less than 80% acid, and does not exceed 1 pint; Packaging Instruction 8A must be followed, recorded from its source on 2026-08-04.

- **Item category:** Acetic acid (UN2790)
- **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:** Mailable if meets Limited Quantity requirements, contains less than 80% acid, and does not exceed 1 pint; Packaging Instruction 8A must be followed _(unconfirmed — we could not tie this to the quote below)_

## What the source says

> Acetic Acid (UN2790): May be mailable if they meet Limited Quantity requirements for air or surface material, contains less than 80 percent acid, and does not exceed 1 pint.

## 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/).