


If you knowingly mail materials that are dangerous or injurious to life, health, or property, for each violation, you face a civil penalty of at least $250 (but not more than $100,000), the costs of any cleanup, and damages. If you are mailing packages that contain hazardous materials (HAZMAT), you must separate HAZMAT packages from all other packages and present them in a container marked "HAZMAT.".Some HAZMAT can only be sent by ground transportation-it can’t go on airplanes.Other HAZMAT is restricted-you can mail it if you follow all the rules.Some HAZMAT is prohibited-you can’t send it through USPS and must use another carrier.HAZMAT also includes lithium batteries (like the ones in cell phones and electronics they contain a lot of energy and can be a fire risk) and liquid mercury: Hazardous materials are substances that could injure people or cause damage if not handled properly, like chemicals or flammable items.
