Skip top navigation
Postal Explorer
Toggle navigation
Postal Explorer
PE Tools
Calculators
Domestic Retail
International Retail
Domestic Business Calculator
International Business Calculator
Domestic Tools
APO/FPO/DPO Restrictions
Zone Charts
Locate a Post Office
ZIP Code Lookup
Service Commitments
International Tools
Country Max Limits and Price Groups
Customs Form Indicator
Other Tools
Metric Conversion Calculator
Publications
Business Mail 101
DMM Advisory
Download DMM, IMM and QSGs
Federal Register Notices
Handbook DM-204
Postal Bulletin
Designing Letter and Reply Mail (PUB 25)
Business Solutions
Address Management Systems
Address Quality
Business Customer Gateway
Business Mail Entry Locator
Direct Mail Advertising
eCommerce Solutions for Web Developers
EDELCON Country List
Labeling Lists
Mailpiece Design
Mailpiece Design Analyst
Periodicals Nonsubscriber % Calculator
Postage Statements
PostalPro
USPS SKU Guide
USPS Marketing Mail Eligibility Decision Tree
Archives
DMM Archive
QSG Archive
IMM Archive
PUB 52 Archive
Price and SKU File Archive
Full Country List
Streamline DMM
Cross Reference
Simplification Crosswalk
Help
About Postal Explorer
Contact Postal Explorer
FAQs
Video Library
PCSC
Search
Skip side navigation
Toggle navigation
Publication 52
Publication 52
Summary of Changes
Transmittal Letter
1 Introduction
11 Purpose
111 General
112 Use
113 Other Reference Sources
12 Scope
121 General
122 Hazardous, Restricted, and Perishable
123 Mailability Premise
13 Additional Information
14 Safety
15 Protecting Personnel
16 Military Postal System
17 Statutory System
18 Trademarks of the USPS
181 Use of USPS Trademarks
182 Common Law Marks or USPS Marks with Pending Trademark Applications
2 General Guidelines
21 Mailability
211 General
212 Mailer Responsibility
213 Authority
214 Appeals
215 Requests for Rulings
216 Nonmailable Matter Found in the Mail
22 Marking Requirements
221 General
222 Matter Excepted From Markings
223 Hazardous Materials Warning Labels and Markings
224 Tag 44 for Hazardous Materials
225 Other Postal Service Labels and Tags
226 Package Orientation Markings
227 Old Markings
228 Shipping Papers
23 Handling Hazardous Materials
24 Emergency Procedures
241 General Requirements
242 Hazard Duration
243 Precautions
245 Hazardous Chemical Emergencies
246 Emergency Telephone Numbers
25 Basic Guidelines for Acceptance and Dispatch
251 Guidelines for Acceptance Personnel
252 Guidelines for Dispatch Personnel
3 Hazardous Materials
31 Definition
32 General
321 U.S. Department of Transportation
322 Postal Service
323 Mailer Responsibility
324 Mailability Rulings
325 DOT Hazardous Materials Warning Labels
326 Shipping Papers
327 Transportation Requirements
328 Postal Service Hazardous Materials Table
33 Hazard Classes
331 Nine Classes
332 Limited Quantity
333 Consumer Commodity
334 Mailable Limited Quantity
335 ORM-D Materials
336 Small Quantity
337 Packaging Requirements for Hazardous Materials
338 Nonmailable Materials Found in the Mailstream
34 Mailability by Hazard Class
341 Explosives (Hazard Class 1)
342 Gases (Hazard Class 2)
343 Flammable and Combustible Liquids (Hazard Class 3)
344 Flammable Solids (Hazard Class 4)
345 Oxidizing Substances, Organic Peroxides (Hazard Class 5)
346 Toxic Substances and Infectious Substances (Hazard Class 6)
347 Radioactive Materials (Hazard Class 7)
348 Corrosives (Hazard Class 8)
349 Miscellaneous Hazardous Materials (Hazard Class 9)
4 Restricted Matter
41 General
411 Definition
412 Mailer Responsibility
413 Rulings
414 Nonmailable Matter Found in the Mails
42 Intoxicating Liquors
421 Definition
422 Mailability
423 Packaging and Marking
43 Firearms
431 Definitions
432 Mailability
433 Legal Opinions on Mailing Firearms
434 Replica or Inert Explosive Devices
435 Nonmailable Firearms Found in the Mails
44 Knives and Sharp Instruments
441 Definitions
442 Mailability
443 Packaging and Marking
444 Nonmailable Knives in the Mails
45 Other Restricted Materials
451 Liquids, Powders, and Odor-Producing Materials
452 Motor Vehicle Master Keys and Locksmithing Devices
453 Controlled Substances and Drugs
454 Unsolicited Promotional Samples
455 Building Construction Material
46 Animal-Fighting Ventures
461 Definitions
462 Mailability
47 Cigarettes and Smokeless Tobacco
471 Definitions
472 Mailability
5 Perishable Matter
51 Definition
511 General Definitions
512 Federal Statutes
52 Animals
521 General Requirements
522 Packaging and Markings
523 Acceptance for Mailing
524 Disposal
525 Nonmailable Live Animals
526 Mailable Live Animals
53 Fresh Foods and Other Perishables
54 Eggs
55 Meats and Meat Products
56 Plants
561 General
562 Quarantines
563 Packaging and Marking
564 Further Information
57 Nonmailable Plant Pests, Injurious Animals, and Illegally Taken Fish or Wildlife
571 General
572 Criminal Penalties
6 International Mail
61 General
611 Refusal by Air Carrier
62 Hazardous Materials: International Mail
621 General Requirements
622 Mailable Hazardous Materials
623 Nonmailable Hazardous Materials
63 Restricted Matter: International Mail
631 APO/FPO/DPO Mail
632 Firearms
633 Inert Replica and Explosive Devices
634 Knives and Sharp Instruments
635 Drugs
636 Controlled Substances
637 Other Restricted Matter
64 Perishable Matter: International Mail
641 APO/FPO/DPO Mail
642 Animals
643 Eggs
644 Plants
645 Fresh Foods and Other Perishables
7 Air Transportation Requirements
71 General
711 Refusal by Air Carrier
72 Hazardous Materials: Air Transportation
721 General Requirements
722 Additional Requirements
723 Hazardous Materials Warning Labels
724 Consumer Commodity and Mailable Limited Quantity Materials
725 Mailer Responsibility
726 Postal Service Handling
727 Refusal by Air Carrier
728 Spills and Leaks
73 Restricted Matter: Air Transportation
731 Refusal by Air Carrier
74 Perishable Matter: Air Transportation
741 General Requirements
742 Live Animals
743 Perishable Matter with Dry Ice
Appendix A
Appendix B
Appendix C
USPS Packaging Instruction 1-3
1A Toy Propellant Devices
1B Safety Fuse
2A Flammable Gases
2B Nonflammable Gases
2C Fire Extinguishers
2D Foodstuffs and Soap Products
2E Audible Fire Alarm Systems
2F Biological Products or Medical Preparations
3A Flammable Liquids
3B Combustible Liquids
3C Cigarette Lighters
3D Ethanol-based Flammable Liquids and Solids
USPS Packaging Instruction 4-6
4A Flammable Solids
4B Safety Matches
5A Oxidizing Substances, Organic Peroxides
6A Toxic Substances
6B Toxic Substances With LD50 Oral Toxicity of 50 mg/kg or Less
6C Category B Infectious Substances
6D Sharps Waste and Other Regulated Medical Waste
6E Used Health Care Products
6F Forensic Material
6G Nonregulated Infectious Materials
6H Exempt Human or Animal Specimens
USPS Packaging Instruction 7-10
7A Radioactive Materials
8A Corrosives
8B Nonspillable Wet Battery
8C Manufactured Devices that Contain Small Amounts of Mercury
9A Dry Ice (Carbon Dioxide Solid)
9B Magnetized Materials
9C Miscellaneous Hazardous Materials
9D Lithium Metal and Lithium-ion Cells and Batteries Domestic
9E Lithium Metal and Lithium-ion Cells and Batteries International and APO/FPO/DPO
10A Small Quantity Provision
10B Cremated Remains
Appendix D
Appendix E
Postal Service Publications and Reference Materials
Other Publications
Index
Publication 52 - Hazardous, Restricted, and Perishable Mail
Mailing Standards of the United States Postal Service
Publication 52 - Hazardous, Restricted, and Perishable Mail
July 2022
Summary of Changes
Transmittal Letter
1 Introduction
11 Purpose
12 Scope
13 Additional Information
14 Safety
15 Protecting Personnel
16 Military Postal System
17 Statutory System
18 Trademarks of the USPS
2 General Guidelines
21 Mailability
22 Marking Requirements
23 Handling Hazardous Materials
24 Emergency Procedures
25 Basic Guidelines for Acceptance and Dispatch
3 Hazardous Materials
31 Definition
32 General
33 Hazard Classes
34 Mailability by Hazard Class
4 Restricted Matter
41 General
42 Intoxicating Liquors
43 Firearms
44 Knives and Sharp Instruments
45 Other Restricted Materials
46 Animal-Fighting Ventures
47 Cigarettes, Smokeless Tobacco, and Electronic Nicotine Delivery Systems
5 Perishable Matter
51 Definition
52 Animals
53 Fresh Foods and Other Perishables
54 Eggs
55 Meats and Meat Products
56 Plants
57 Nonmailable Plant Pests, Injurious Animals, and Illegally Taken Fish or Wildlife
6 International Mail
61 General
62 Hazardous Materials: International Mail
63 Restricted Matter: International Mail
64 Perishable Matter: International Mail
7 Air Transportation Requirements
71 General
72 Hazardous Materials: Air Transportation
73 Restricted Matter: Air Transportation
74 Perishable Matter: Air Transportation
Appendix A
Appendix B
Appendix C
USPS Packaging Instruction 1A
USPS Packaging Instruction 1B
USPS Packaging Instruction 2A
USPS Packaging Instruction 2B
USPS Packaging Instruction 2C
USPS Packaging Instruction 2D
USPS Packaging Instruction 2E
USPS Packaging Instruction 2F
USPS Packaging Instruction 3A
USPS Packaging Instruction 3B
USPS Packaging Instruction 3C
USPS Packaging Instruction 3D
USPS Packaging Instruction 4A
USPS Packaging Instruction 4B
USPS Packaging Instruction 5A
USPS Packaging Instruction 6A
USPS Packaging Instruction 6B
USPS Packaging Instruction 6C
USPS Packaging Instruction 6D
USPS Packaging Instruction 6E
USPS Packaging Instruction 6F
USPS Packaging Instruction 6G
USPS Packaging Instruction 6H
USPS Packaging Instruction 7A
USPS Packaging Instruction 8A
USPS Packaging Instruction 8B
USPS Packaging Instruction 8C
USPS Packaging Instruction 9A
USPS Packaging Instruction 9B
USPS Packaging Instruction 9C
USPS Packaging Instruction 9D
USPS Packaging Instruction 9E
USPS Packaging Instruction 10A
USPS Packaging Instruction 10B
USPS Packaging Instructions 10C
USPS Packaging Instruction 10D
Appendix D
Appendix E
Postal Service Publications and Reference Materials
Other Publications
Index