Category B Infectious Substances

Infectious substance means a material known or reasonably expected to contain a pathogen. A pathogen is a microorganism that can cause disease in humans or animals. Examples of pathogens include bacteria, viruses, fungi, and other infectious agents. An infectious substance must be assigned to one of the following two packaging categories:

• Category A: Category A infectious substances are not mailable.
• Category B: An infectious substance that does not meet the criteria for inclusion in Category A. A mailpiece known or suspected to contain a Category B infectious substance is mailable as described in 346.

Cigarettes, Smokeless Tobacco, and Electronic Nicotine Delivery Systems (ENDS)

Cigarettes, Smokeless Tobacco, and Electronic Nicotine Delivery Systems (ENDS) are generally non-mailable, unless authorized by an exception, if all PACT ACT related conditions of mailability are met. 

Please click here to view the final Federal Register Notice regarding the treatment of e-cigarettes in the mail.

Please click here to view the Postal Bulletin regarding Publication 52 Revision: Cigarettes, Smokeless Tobacco, and Electronic Nicotine Delivery Systems

Drug Mailback Program

DEA registrants wishing to become controlled substances “mail-back collectors” must obtain authorization from the DEA prior to conducting a mail-back program. They must also have the ability to destroy the returned substances onsite. DEA-registered mail-back collectors must also obtain an authorization from the USPS director, Product Classification prior to the implementation of any mail-back program.

Ethanol Based Flammable Liquids & Solids

Certain limited quantities of flammable liquids and solids containing ethyl alcohol are permitted in the domestic mail via air transportation, with special authorization from the director, Product Classification when all applicable requirements in 343.27 are met.

Lighters

A lighter equipped with an ignition element and containing fuel is classified as a Class 3 flammable liquid. A lighter containing a flammable gas is classed as a Division 2.1 flammable gas. A lighter that contains either flammable liquid or flammable gas is permitted in domestic mail via surface transportation only with prior written approval, provided all the applicable requirements of 343.25 are met.

Polywrap and Polywrap Manufacturers

Manufacturers and mailers of flat-size mail must comply with USPS-T-3204, which went into effect February 4, 2007. In 2006, the USPS conducted a thorough study of automatable polywrap films to ensure compatability of automation flats with flats sequencing systems (FSS) and stand alone mail prep (SAMP) according to standards AFSM 100 and UFSM 1000.

Safety Fuse

Safety fuses consist of a core of black powder overspun with yarns, waterproofing compounds, and/or tapes. A safety fuse assigned identification number UN0105 and classed as a Division 1.4S explosive may be mailed only as permitted in 341.22b and when properly packaged as follows.

Sharps and Regulated Medical Waste

Regulated medical waste and sharps medical waste as defined in 346.12f and 346.12g and containing materials classified as Category B infectious substances are permitted for mailing provided that all applicable requirements specified in 346.322 are met. For packaging instructions for medical professional packages, refer to 346.322b–d.

Toy Propellant Devices

The proper shipping name for a mailable toy propellant device is “model rocket motor” or “igniter.” A device that is assigned identification number NA0323 or UN0454 and classed as a Division 1.4S explosive is eligible for mailing in domestic mail via surface transportation only, provided that all requirements are met and the device is properly package. See specifications in 341.22a.

USPS® Container Requirements for Adult Birds

Disease-free adult birds may be mailed domestically when shipped under all applicable governmental laws and regulations, including the Lacey Act, the Endangered Species Act (ESA), and regulations of the U.S. Department of Agriculture, U.S. Fish and Wildlife Service, and any state, municipal, or local ordinances.