---
type: restriction
id: usps-sharps-and-regulated-medical-waste-containing-category-b-infectious-substance-un
asset: shipping-restrictions-by-class
title: "Sharps and regulated medical waste containing Category B infectious substance (UN3291) — Postal shipping restrictions by item category"
sources:
  - https://pe.usps.com/text/pub52/pub52c3_025.htm
source_quote: "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."
generated: true
harvested: 2026-08-04
stale_after: 2027-08-04
item_category: "Sharps and regulated medical waste containing Category B infectious substance (UN3291)"
carrier: "USPS"
restriction_type: "restricted"
scope: "domestic mail via USPS Ground Advantage only"
conditions: "Permitted via USPS Returns Service via USPS Ground Advantage only; vendor must obtain prior authorization; strict packaging, testing, labeling requirements apply"
verified: true
unverified_fields: conditions
---
**Item category:** Sharps and regulated medical waste containing Category B infectious substance (UN3291)

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail via USPS Ground Advantage only

**Conditions:** Permitted via USPS Returns Service via USPS Ground Advantage only; vendor must obtain prior authorization; strict packaging, testing, labeling requirements apply

> 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>