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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 #22-0131

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

Interpretation Response Details

Response Publish Date:

Company Name: Powin

Individual Name: Thomas Kerr

Location State: OR Country: US

View the Interpretation Document

Response text:

January 9, 2023

Mr. Thomas Kerr
Program Manager
20550 SW 115th Ave
Tualatin, OR  97062

Reference No. 22-0131

Dear Mr. Kerr:

This letter is in response to your December 6, 2022, email and letter requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to use of hazardous materials (HM) description "UN3536, Lithium batteries installed in cargo transport unit" and the associated use of the term cargo transport unit (CTU) as it relates to this HM description.

You state that your company has designed and manufactured a power storage unit called the Powin Stack750 Centipede Energy Segment. This unit contains lithium batteries with a maximum energy capacity of 750 kWh per segment, and weighs 20,000 lbs. You also state that the unit includes a fully-integrated direct current block, independent sensors (i.e., gas and temperature), and a fire suppression system. Finally, you provide diagrams that demonstrate during vessel, rail, and highway transportation, the unit would be secured to a either a truck-trailer, flat-rack, roll-on / roll-off, or bulk freight configuration. Your company is seeking clarification that the unit secured to a flat-rack, roll-on / roll-off, truck-trailer, or as bulk-freight meets the transportation requirements and is appropriately described and classed using UN3536.

Based on the information and illustrations provided, it is the opinion of this Office that the Stack750 Centipede Energy Segment secured to a flat-rack, roll-on / roll-off, truck-trailer, or as bulk-freight is appropriately described and classed, as "UN3536,

Lithium batteries installed in cargo transport unit lithium ion batteries or lithium metal batteries, 9" and meets the transportation requirements of special provision 389 assigned to the HM description.

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, 172.102

Regulation Sections

Section Subject
172.101 Purpose and use of hazardous materials table
172.102 Special provisions