# Sharps and regulated medical waste containing Category B infectious substance (UN3291) — Postal shipping restrictions by item category

For Sharps and regulated medical waste containing Category B infectious substance (UN3291), carrier is USPS; restriction type is restricted; scope is domestic mail via USPS Ground Advantage only; conditions is Permitted via USPS Returns Service via USPS Ground Advantage only; vendor must obtain prior authorization; strict packaging, testing, labeling requirements apply, recorded from its source on 2026-08-04.

- **Item category:** Sharps and regulated medical waste containing Category B infectious substance (UN3291)
- **Carrier:** USPS _(our reading, not quoted from the source)_
- **Restriction type:** restricted _(our reading, not quoted from the source)_
- **Scope:** domestic mail via USPS Ground Advantage only _(our reading, not quoted from the source)_
- **Conditions:** Permitted via USPS Returns Service via USPS Ground Advantage only; vendor must obtain prior authorization; strict packaging, testing, labeling requirements apply _(unconfirmed — we could not tie this to the quote below)_

## What the source says

> Regulated medical waste and sharps medical waste as defined in 346.12 ( f ) and 346.12 ( g ) and containing materials classified as Category B infectious substances must be marked UN3291 and are permitted for mailing only using USPS Returns Service (refer to DMM 505.3) via USPS Ground Advantage service.

## 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/).