Revised USPS Hazmat Packaging Standards for Mail

New Rules for Hazmat Mailers Take Immediate Effect

Effective January 27, 2025, the US Postal Service has revised its standards for mailing hazmat/dangerous goods to require "rigid" outer packaging of a certain strength for most regulated materials. USPS announced the changes to Publication 52, Hazardous, Restricted, and Perishable Mail, in a Final Rule. 

Other revisions in the Final Rule include:

• Revising the requirements for mailing lithium batteries.
• Removing quantity restrictions for nonregulated toxic materials like pesticides and insecticides, provided that the new packaging requirements are followed.
• Removing the requirement to include a phone number on the lithium battery mark.

The Postal Service cites a concerning increase in hazmat mail incidents between 2020 and 2022 as a key influence for new, more stringent mailability rules. A boom in eCommerce shipping, USPS believes, led to more incidents involving hazardous materials released during transportation and/or removed from the mail system. 

Changes made in 2023, USPS says, already helped lower the incident rate by 20%. 

New Packaging Strength Requirement (All Hazmat)

Moving forward, mailers of hazardous materials must use rigid outer packaging that meets minimum strength requirements based on “edge crush” and “burst test” performance. USPS defines “rigid” to mean:
 

“Unable to bend or be forced out of shape, not flexible. Rigid outer packaging is generally interpreted to mean a fiberboard (cardboard) box or outer packaging of equivalent strength, durability, and rigidity.”

Revised Rules for Lithium Batteries by Mail

For shippers of lithium batteries contained-in-equipment by mail, the rule allows the use of padded or poly bags as outer packaging, provided the equipment containing the batteries is placed in a secondary container (i.e., the original manufacturer’s box) that can withstand a 1.2-meter drop test.

Read the USPS Final Rule in the January 27, 2025 Federal Register. 

Tags: hazmat, hazmat shipping, USPS