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U.S. Department of Transportation U.S. Department of Transportation Icon United States Department of Transportation United States Department of Transportation

Interpretation Response #22-0102

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

Interpretation Response Details

Response Publish Date:

Company Name: Transportation Development Group, LLC

Individual Name: Jim Powell

Location State: AZ Country: US

View the Interpretation Document

Response text:

November 7, 2022

Mr. Jim Powell
Transportation Development Group, LLC
190 W. Continental Road
Suite 216-401
Green Valley, AZ  85614

Reference No. 22-0102

Dear Mr. Powell:

This letter is in response to your September 23, 2022, email requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to a lithium battery contained in equipment. Specifically, you state that your client ships a portable headset for hearing tests that is packed in a hard-shell impact resistant PelicanTM case. You also state that the portable headset is powered by a lithium polymer cell that is less than 20 Watt-hours (Wh) and—to prevent accidental activation of the equipment—the device uses a power management integrated circuit placed in “factory shipping mode” which prevents any electrical current from being drawn from the cell except for a very small electrical current of 0.23 microamps (µA)1. You further note that pressing the power button while in "factory shipping mode" has no effect on the device, and the portable headset can only be turned on and activated if a USB charging cable. Therefore, you ask whether the packing method of the portable headset—as described—would comply with the requirements of § 173.185(b)(2)(iii) to prevent accidental activation of the equipment.

Additionally, you state the portable headset also contains a real-time clock that is powered by a small, non-rechargeable coin cell battery with a lithium content that is less than 0.1 grams. When the portable headset is shipped in "factory shipping mode," the real-time clock draws a small electrical current of 0.67 µA to keep track of time. You ask whether this would satisfy the requirements of § 173.185(b)(2)(iii) as well.

Based on the information you have provided; it is the opinion of this Office that the manner of packing as described for both scenarios would comply with the requirements of § 173.185(b)(2)(iii) for prevention of accidental activation of the equipment.

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


1 μA is a unit of electric current, equal to one millionth of an ampere.

Regulation Sections

Section Subject
173.185 Lithium cells and batteries