# intoxicating liquors - denatured flammable or combustible — Postal shipping restrictions by item category

For intoxicating liquors - denatured flammable or combustible, carrier is USPS; restriction type is restricted; scope is domestic mail; conditions is If denaturing agents such as sodium bisulfate (a corrosive) or mercuric chloride (a poison) are used, substance must meet mailability requirements for Class 8 corrosive or Division 6.1 toxic substance; flammable or combustible contents must meet Class 3 requirements, recorded from its source on 2026-08-04.

- **Item category:** intoxicating liquors - denatured flammable or combustible _(unconfirmed — we could not tie this to 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 _(our reading, not quoted from the source)_
- **Conditions:** If denaturing agents such as sodium bisulfate (a corrosive) or mercuric chloride (a poison) are used, substance must meet mailability requirements for Class 8 corrosive or Division 6.1 toxic substance; flammable or combustible contents must meet Class 3 requirements _(unconfirmed — we could not tie this to the quote below)_

## What the source says

> if denaturing agents are used, such as sodium bisulfate (a corrosive) or mercuric chloride (a poison), the substances must meet the mailability requirements for Class 8 corrosive material or a Division 6.1 toxic substance

## Source

- https://pe.usps.com/text/pub52/pub52c4_006.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/).