HAZMAT - Hazardous Materials

Certain items may appear safe because they are used during everyday activities around the house, but they can actually pose a significant risk during transportation. Some common HAZMAT items that you might not think of as “safe” include flammable aerosol products (spray disinfectants, spray paints, and hairspray), lithium batteries, safety matches, perfume, and cosmetic products, such as nail polish and nail polish remover. Although some of these materials are allowed to travel through the mail, there are strict quantity limits, packaging, and marking requirements.

Corrosive materials are substances that can cause severe damage to skin, eyes, metal, and other materials through chemical reactions. Many corrosive products are commonly used in homes and businesses, including drain cleaners, pool chemicals, acids, industrial cleaning agents, and certain automotive fluids.

Corrosive substances are regulated in the mail and may be either prohibited or restricted, depending on their composition, quantity, and packaging. Improperly prepared or undeclared corrosive materials can leak during transportation, causing injury to Postal Service employees and damage to mail and equipment.

Lithium batteries are used to power many types of electronics, from cell phones, laptops, and tablets to wireless headphones, toys, and portable tools. Because these batteries can catch fire and possibly explode when improperly prepared and shipped, they are considered hazardous materials and remain highly regulated in transportation. When correctly prepared, declared, and shipped in quantities below the USPS threshold, these risks can be reduced and avoided. For domestic shipments, lithium-ion batteries rated at 100 watt-hours (Wh) or less may be mailed in limited quantities when properly installed in or packaged with the equipment they operate and prepared in accordance with USPS requirements. Larger lithium batteries, such as those that power e-bikes, scooters, and generators, are strictly prohibited from being mailed because they consistently exceed the 100 Wh limit.

International mailing of lithium batteries is more restrictive than domestic mailing and prohibits the mailing of many standalone lithium batteries.

Liquid mercury, on its own or contained in various items, is prohibited in the mail. This extremely hazardous substance produces toxic vapors if exposed to air and causes mercury poisoning if the vapors become inhaled. Older-styled thermometers, blood pressure gauges, and barometers — which often contain liquid mercury — may become damaged or broken during the shipping process. The threat of serious illness or injury caused by exposure to a leaking mercury package is never worth shipping the item.

These brilliant celebratory displays of color and design are beautiful to behold in the sky when handled legally and properly. However, fireworks, including small consumer items such as sparklers, are illegal to ship in the USPS network. Illegal shipments of fireworks pose a significant hazard while in air transportation and endanger the lives of Postal Service employees and the traveling public.

The U.S. Department of Transportation categorizes small arms ammunition as explosive materials, which are strictly prohibited from the mail. Ammunition that is designed to be fired from a pistol, revolver, rifle, or shotgun, as well as associated primers and blank cartridges (including those designed for tools) and propellant powder for use in any firearm, is prohibited from mailing. Under federal law, it is illegal to send these types of ammunition, domestically or internationally, in the USPS network. Small arms ammunition poses a significant danger to Postal Service employees, equipment, and customers, supporting potential civil penalties and criminal charges.

The shipment of firearms through the USPS network is regulated by the Gun Control Act of 1968 and Pub 52. The Postal Inspection Service is regularly engaged with our federal, state, and local partners to thwart any loss associated with firearms, stop any illicit firearms trafficking through the mail, and ensure the safety of our infrastructure, employees and customers.

When presenting a package for mailing, you are responsible for knowingly and accurately declaring its contents. Postal Service employees will ask whether your shipment contains hazardous materials such as lithium batteries, perfume, mercury, aerosols, or other restricted items. Providing complete and truthful information helps ensure your package is handled safely and in compliance with federal regulations.

Improperly prepared or undeclared hazardous materials can pose serious safety risks during transportation. Failure to comply with mailing requirements may result in the package being refused, returned, and the mailer being subject to civil and/or criminal penalties.
To learn more about the USPS guidelines on hazardous, prohibited, and restricted mailings visit: https://www.usps.com/ship/shipping-restrictions.htm