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Interpretation Response #22-0095

Below is the interpretation response detail and a list of regulations sections applicable to this response.

Interpretation Response Details

Response Publish Date:

Company Name: Environmental Resource Center

Individual Name: Kristie Absher

Location State: NC Country: US

View the Interpretation Document

Response text:

March 17, 2023

Kristie Absher
Senior Consultant
Environmental Resource Center
101 Center Pointe Drive
Cary, NC  27513

Reference No. 22-0095

Dear Ms. Absher:

This letter is in response to your June 17, 2022, letter, January 30, 2023, email, and subsequent phone conversation with a member of my staff requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to the transportation of lithium metal batteries contained in acoustic devices used for sound recordings called "rockhoppers." Specifically, you state that your research team deploys rockhoppers as part of an ocean research program. The rockhoppers are powered by an 8.8 kg lithium metal battery where the batteries are hermetically sealed inside the device to prevent water intrusion and thus cannot be removed for transportation purposes. Furthermore, the rockhoppers—which are made of glass—are housed in a buoy type unit for protection against damage and then packaged in a sturdy case when transported. The weight of the buoy type unit is over 100 lbs. and the weight of the total package—to include all equipment and packaging—is less than 150 lbs. Lastly, you state that these rockhoppers would be transported by highway to a boat pier for loading onto a vessel to then launch the rockhoppers in the ocean. You ask when referencing "UN3091, Lithium metal batteries contained in equipment including lithium alloy batteries, 9" as it relates to the materials of trade (MOTs) exception, does the 30 kg weight limitation—as applied to Class 9 articles without a packing group designation in the § 172.101 hazardous materials table—apply to the total package, the buoy type unit containing a rockhopper, the rockhopper, or just the lithium metal battery contained in the rockhopper.

Based on the information you have provided, the 30 kg (66 lbs.) weight limitation applies to the rockhopper because the buoy type unit and sturdy case may be considered a means of securing the rockhopper against shifting during transport. In accordance with § 173.6(b)(3), outer packaging is not required for articles that are secured against shifting by cages, carts, bins, boxes, compartments or by other means. Thus, when utilizing the MOTs provisions for this specific scenario, only the combined weight of the lithium metal battery installed in the rockhopper should be considered for the 30 kg gross weight limit.

I hope this information is helpful. Please contact us if we can be of further assistance.


Dirk Der Kinderen
Chief, Standards Development Branch
Standards and Rulemaking Division

172.101, 173.6(b)(3)

Regulation Sections

Section Subject
172.101 Purpose and use of hazardous materials table
173.6 Materials of trade exceptions