Thank you for choosing to send your package via the United States Postal Service. We know that you have choices, and of those choices the USPS is often the least cost-effective, reliable, and cool. But whatever your reason—perhaps you are a hipster mailing something ironically—we’ll do our federal governmental best to serve your needs.
That said, there are some things you’re not allowed to send through the U.S. mails. Restricted materials come in a wide variety of forms and can be chemical, biological, radioactive, or some thrilling combination of two or more of these. An example of a (banned) chemical is hydrogen—a highly combustible, diatomic gas. Something that is both chemical and biological is a hot dog. And something that is chemical, biological, and radioactive is Spider-Man’s blood. You may not mail Spider-Man’s blood. And we don’t even want to know how you got it in the first place.
But even many common household and consumer products may not be mailed. These materials might not be dangerous on your shelf at home, or under your sink, or in your garage, or in the trunk of your car, or under your floorboards, or in your pants pocket, but they might become a hazard when shaken or exposed to temperature or pressure changes. The following are some examples of household products that may be mailed, but with specific restrictions:
Examples (only) of non-mailable items include: air bags (both the vehicle safety device and simple bags filled with air); ammunition; explosives; and gasoline. If you ever need to send airbags, ammunition, explosives, and gasoline somewhere, however, please inform USPS personnel, because that sounds like a hell of a party and we want to be there.
Besides hazardous materials and restricted matter, there is also perishable matter, which is anything that can deteriorate in the mail and thereby lose value and/or cause an obnoxious odor, nuisance, or disturbance under ordinary mailing conditions. Some perishable matter may nevertheless be sent at the mailer’s own risk when it is packaged as required.
Please note: Criminal penalties are specified in Title 18 of the United States Code for mailing anything that is non-mailable. We have a saying: “Don’t use the mail if you can’t go to jail.”
The U.S. Postal Service. We’re sorry, there’s no record of that in our system.™
Matthew David Brozik wrote this and many other short humor pieces, which have been published in print and online by The New Yorker, Adult Swim, McSweeney’s Internet Tendency, Grin & Tonic, The Big Jewel, and no one.