Mailing Standards of the United States Postal Service
Publication 52 - Hazardous, Restricted, and Perishable Mail
April 2022

  Summary of Changes

Transmittal Letter

1 Introduction
2 General Guidelines
3 Hazardous Materials
4 Restricted Matter
5 Perishable Matter
6 International Mail
7 Air Transportation Requirements
Appendix A

Appendix B

Appendix C
Appendix D

Appendix E