Interpretation Response #26-0051
Below is the interpretation response detail and a list of regulations sections applicable to this response.
Interpretation Response Details
Response Publish Date:
Company Name: Fibrebond
Individual Name: Chet Carpenter
Location State: LA Country: US
View the Interpretation Document
Response text:
July 8, 2026
Chet Carpenter
Director of Technical Sales
Fiberbond
1300 Davenport Drive
Minden, LA 71055
Reference No. 26-0051
Dear Mr. Carpenter:
This letter is in response to your April 24, 2026 letter regarding the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) and the shipment of lithium batteries. In your letter you reference a previous Letter of Interpretation (LOI).1 Specifically, you ask for confirmation regarding the appropriate classification of your shipment of lithium-ion batteries housed in shippable buildings.
1 Fujitrans USA Inc., Letter of Interpretation Reference Number 22-0086, available at: https://www.phmsa.dot.gov/regulations/title49/interp/22-0086
Can PHMSA confirm your ability to ship a set of lithium-ion batteries tested to UN3480, and packed within custom-manufactured engineered racks in a shippable building or container per the requirements in UN3536, including Special Provision 389?
No. As stated in § 173.22, it is strictly the responsibility of the shipper to properly classify, test, and package hazardous materials. Because PHMSA does not evaluate or certify specific designs or operations, we cannot definitively confirm whether you have packaged your shipment correctly. However, your shipment may be classified as "UN3536, Lithium batteries installed in a cargo transport unit," provided it meets all the conditions outlined in Special Provision 389.
To utilize this classification and provision, your shippable building and the internal batteries must meet the following criteria:
- The lithium batteries must be designed only to provide power external to the cargo transport unit.
- The batteries must meet the requirements of § 173.185(a) and contain the necessary systems to prevent overcharge and over-discharge between the batteries.
- The batteries must be securely attached to the interior structure of the unit (e.g., your custom-manufactured racks) to prevent short circuits, accidental operation, and significant movement during transport.
- The unit must not contain any hazardous materials other than those necessary for the safe and proper operation of the cargo transport unit itself (such as fire extinguishing systems or air conditioning systems).
- The cargo transport unit must display the UN number in accordance with § 172.332 and be placarded on two opposing sides.
I hope this information is helpful. Please contact us if we can be of further assistance.
Sincerely,
Alexander Wolcott
Acting Chief, Regulatory Review and Reinvention Branch
Standards and Rulemaking Division
172.102 172.332 173.22 173.185(a)