SUPPLEMENTARY INFORMATION:

The Postal Service hereby amends Publication 52, Hazardous, Restricted, and Perishable Mail (Pub 52 or Publication 52), with the provisions set forth herein. While not codified in title 39 of the Code of Federal Regulations (CFR), Publication 52 is a regulation of the Postal Service, and changes to it may be published in the Federal Register . 39 CFR 211.2(a)(2). Moreover, Publication 52 is incorporated by reference into Mailing Standards of the United States Postal Service, Domestic Mail Manual (DMM) section 601.8.1, which is incorporated by reference, in turn, into the Code of Federal Regulations. 39 CFR 111.1 and 111.3. Publication 52 is publicly available, in a read-only format, via the Postal Explorer® website at pe.usps.com. In addition, links to Postal Explorer are provided on the landing page of USPS.com, the Postal Service's primary customer-facing website, and on Postal Pro, an online informational source available to postal customers.

Summary of New Measures

On August 6, 2026, the Postal Service published a notice of proposed rulemaking (91 FR 50741) requiring mailers to individually address and number live animal shipments composed of multiple containers bound together for shipment, recommended mailers write the recipient's name and address directly on the packaging of adult bird shipments and prohibited the reuse of fiberboard containers for all live animal shipments.

Response to Comments

In response to the proposed rule, the Postal Service received 32 formal responses to the proposed changes to Pub 52. The comments received are as follows:

Comment: One commenter suggested that USPS establish stronger protection against temperature extremes, minimize transportation and delays, require clear emergency procedures to protect animal welfare, require appropriate employee training, review which animals are appropriate for shipment at all and consider prohibiting live animal shipments when safe transportation can't be assured.

Response: The Postal Service appreciates this feedback. Currently, embargo notices are issued for live animal shipments when there are travel interruptions due to weather related events or holiday transportation schedules are minimized. To the extent possible, the Postal Service limits live animal exposure to temperature extremes while in transit and ensures all animals are safely shielded from the elements while awaiting transport. Alternatively, the mailer must also ensure that the live animal shipments are protected against extreme temperatures by properly packaging them and considering both originating and destinating weather conditions when shipping, especially during summer and winter seasons. The postal service has been actively creating and providing additional education related to emergency procedures and proper handling practices for live animals.

Comment: Several commenters requested that the name and address requirement be extended to all lives shipments not just adult birds, urged USPS to modify its delivery time period to 48 hours for day-old poultry, require a delivery by date on the container for day-old poultry; and employ specialized tracking and data collection on lives perished to better understand the root causes of documented issues, urges climate-controlled transportation modes, requests that USPS issue moratoriums on the acceptance of lives as it deems necessary.

Response: The addressing requirement may be considered for all live animal shipments in a future regulatory update. The Postal Service believes the 48-hour delivery time is not necessary as the conditions of acceptance are that the day-old poultry must not be more than 24 hours old, can be delivered within 72 hours of hatching and the hatching date and hour are required to be indicated on the shipment. The Postal Service utilizes tracking data to identify live animal shipments and monitors data related to incidents to determine root causes for documented issues when shipments are accurately identified by the mailer through application of the pertinent USPS extra service codes within their electronic shipping files. Climate-controlled transportation for all modes is not currently feasible, but to the extent possible, the Postal Service limits live animal exposure to temperature extremes while in transit and ensures they are shielded from the elements while awaiting transport. Alternatively, the mailer must also ensure that the live animal shipments are protected against extreme temperatures by properly packaging them and considering both originating and destinating weather conditions when shipping, especially during summer and winter seasons. As mentioned in the previous comment response, the Postal Service does employ embargoes for live animal shipments when issues arise.

Comment: Several commenters suggested that USPS require advanced reservations and confirm transportation capacity.

Response: The Postal Service is in contact with major animal shippers and is provided advance notice of large shipments of live animals.

Comment: One commenter suggested that USPS includes specific test standards for all lives outer packaging and suggests an alternative to the address and phone number requirement of a barcode instead and to require each container in a multi-container shipment to have its own address label.

Response: The Postal Service appreciates the feedback and will ( printed page 66003) possibly consider this in a future rulemaking process.

Comment: One commenter suggested that live animals should only be shipped by overnight delivery.

Response: Depending upon the type of live animal being shipped and the shipping distance, Priority Mail and USPS Ground Advantage may also be used to ensure the shipment arrives safely.

Comment: One commenter suggested that USPS prohibit the mailing of all adult roosters due to gamecock breeders and cockfighters illegal use of the Postal Service to mail animals for fighting ventures.

Response: The Postal Service permits domestic mailings of disease-free adult birds when in compliance with all applicable governmental laws and regulations, including the Lacey Act, the Endangered Species Act (ESA), the Animal Welfare Act, regulations of the U.S. Department of Agriculture, U.S. Fish and Wildlife Service, and any state, municipal, or local ordinances. Any violation of these regulations is handled by local authorities and the Postal Inspection Service.

Comment: One commenter indicates USPS has no procedures or precautions within USPS publications to exclude shipments of live animals used for animal-fighting ventures. The commenter suggests USPS refuse shipments of roosters or imposes more stringent requirements by reviewing and recording interstate health documentation for each rooster, mandate mailers provide written certification of each rooster's non-fighting purpose, limit the number of roosters that can be shipped per day and restrict the breeds of roosters that are permitted.

Response: The Postal Service will research these suggestions and determine whether more stringent requirements will be considered in a future rulemaking process.

The Postal Service adopts the following changes to Publication 52, Hazardous, Restricted, and Perishable Mail, incorporated by reference into Mailing Standards of the United States Postal Service, Domestic Mail Manual (DMM), section 601.8.1, which is further incorporated by reference in the Code of Federal Regulations. 39 CFR 111.1, 111.3. Publication 52 is also a regulation of the Postal Service, changes to which may be published in the Federal Register . 39 CFR 211.2(a). Accordingly, for the reasons stated in the preamble, the Postal Service amends Publication 52 as follows:

Publication 52—Hazardous, Restricted and Perishable Mail

5 Perishable Matter

52 Animals

521 General Requirements

[Add note at the bottom of section under item c. to read as follows:]

Note:

Due to the high likelihood of degradation during transportation, fiberboard containers must not be reused for live animal shipments.

522 Packaging and Markings

522.1 Container Construction

[Revise section to read as follows:]

Containers used to mail perishable matter must be constructed to protect and securely contain the contents.

Shipping containers for mailable live animals must, at a minimum, be made of 275-pound test, double-wall, corrugated, weather-resistant fiberboard (W5c) or equivalent. When multiple containers are strapped together, a single shipping label should be applied but each container must have its own address label. Additionally, the containers must be numbered sequentially ( e.g., “1 of 5”, “2 of 5,” etc.) to help ensure proper handling if they become separated during transit.

USPS-produced packaging, including Flat Rate containers, is not eligible for use. Additional container requirements apply to mailable adult birds (refer to 526.4).

526 Mailable Live Animals

526.4 Adult Birds

526.42 Mailability Requirements

[Add the following to the end of the section:]

Note:

It is recommended that the name and address of the recipient also be written on the packaging in addition to the shipping label.

USPS Packaging Instruction 10D

Adult Bird Boxes

Marking

[Revise Marking section to read as follows:]

Labels and markings must be placed on the address side of the mailpiece unless specified differently in 221.1 and 325.1.

Each container must be marked with the following information:

“Live Birds—USPS Approved Container # (once issued).”

Complete sender's and recipient's addresses (including phone numbers) on the outer packaging for the necessary notification by Postal Service personnel.

Directional arrows indicating “up” position (on at least two sides of the container).

Note:

It is recommended to write the name and address of the recipient directly on the package in case shipping label becomes detached during shipment.

91 FR 66002