# Trimethylamine, aqueous solutions with not more than 50 percent trimethylamine by mass · USPS · III — Mailing and air-carriage restrictions by item category

For Trimethylamine, aqueous solutions with not more than 50 percent trimethylamine by mass · USPS · III, item category is Trimethylamine, aqueous solutions with not more than 50 percent trimethylamine by mass; carrier is USPS; dot packing group is III; restriction type is restricted; scope is domestic mail: surface only (air prohibited), recorded from its source on 2026-08-29.

- **Item category:** Trimethylamine, aqueous solutions with not more than 50 percent trimethylamine by mass _(verified: appears in the quote below)_
- **Carrier:** USPS _(our reading, not quoted from the source)_
- **DOT packing group:** III _(verified: appears in the quote below)_
- **Restriction type:** restricted _(our reading, not quoted from the source)_
- **Scope:** domestic mail: surface only (air prohibited) _(our reading, not quoted from the source)_
- **Conditions:** Hazard class 3, UN1297, packing group III; domestic mail air: Prohibited; domestic mail surface: 3A

## What the source says

> Trimethylamine, aqueous solutions with not more than 50 percent trimethylamine by mass 3 UN1297 III Prohibited 3A

## Source

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

Last verified: 2026-08-29. Review by: 2027-08-29.
Part of [Mailing and air-carriage restrictions by item category](https://referencesource.org/shipping-restrictions-by-class/).