Transmittal Letter

Hazardous, Restricted, and Perishable Mail

Publication 52 September 7, 2023

Transmittal Letter

A. Purpose. Publication 52, Hazardous, Restricted, and Perishable Mail, provides important information to help mailers determine what may be mailed and how certain items must be packaged to keep the mail safe. It also provides guidance to Postal Service™ employees accepting this mail.

Publication 52 is available on Postal Explorer® at

Customers may also consult their local postmaster or manager of business mail entry for additional information about hazardous materials in the mail.

B. Effective Date. This edition is effective September 7, 2023. All previous issues of Publication 52 are obsolete.

C. Availability.
Public: The public can access Publication 52 in PDF and HTML formats on Postal Explorer at

Postal Service: Postal Service employees can access Publication 52 in PDF and HTML formats on the USPS Web site.

D. How to Use This Book. An introduction is located at the beginning of the book. It explains the purpose and scope of the book, as well as the need to protect Postal Service employees and customers from potentially dangerous materials in the mail. In the appendices, we have included a hazardous materials table, packaging instructions for mailable materials, and a glossary of terms.

E. Comments. Contact your local Post Office, business mail entry office, or the Pricing and Classification Service Center (PCSC) with comments or questions about our mailing standards (see DMM 608.8.4 for addresses and telephone numbers of business mail entry offices and the PCSC).


signature of Steven W. Monteith

Steven W. Monteith
Chief Customer and Marketing Officer
and Executive Vice President