# Category A infectious substances (UN2814, UN2900) — Postal shipping restrictions by item category

For Category A infectious substances (UN2814, UN2900), carrier is USPS; restriction type is prohibited; scope is all mail including international; conditions is Category A infectious substances (capable of causing permanent disability or life-threatening disease in healthy humans/animals) are nonmailable, recorded from its source on 2026-08-04.

- **Item category:** Category A infectious substances (UN2814, UN2900) _(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:** all mail including international _(our reading, not quoted from the source)_
- **Conditions:** Category A infectious substances (capable of causing permanent disability or life-threatening disease in healthy humans/animals) are nonmailable

## What the source says

> Category A: An infectious substance transported in a form capable of causing permanent disability or life-threatening or fatal disease in otherwise healthy humans or animals when exposure occurs. Category A infectious substances are nonmailable.

## Source

- https://pe.usps.com/text/pub52/pub52c3_025.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/).