# Division 2.3 Toxic Gases — domestic air — Postal shipping restrictions by item category

For Division 2.3 Toxic Gases, item category is Division 2.3 Toxic Gases — domestic air; carrier is USPS; restriction type is prohibited; scope is domestic mail via air transportation; conditions is Division 2.3 toxic gases are prohibited from domestic air mail, recorded from its source on 2026-08-04.

- **Item category:** Division 2.3 Toxic Gases — domestic air _(unconfirmed — we could not tie this to 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 via air transportation _(our reading, not quoted from the source)_
- **Conditions:** Division 2.3 toxic gases are prohibited from domestic air mail _(unconfirmed — we could not tie this to the quote below)_

## What the source says

> Division 2.1 (flammable gases) and Division 2.3 (toxic gases) are prohibited.

## Source

- https://pe.usps.com/text/pub52/pub52c3_021.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/).