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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 #12-0019 ([Council on the Safe Transportation of Hazardous Articles, Inc.] [Mr. Tom Ferguson])

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

Interpretation Response Details

Response Publish Date:

Company Name: Council on the Safe Transportation of Hazardous Articles, Inc.

Individual Name: Mr. Tom Ferguson

Location State: VA Country: US

View the Interpretation Document

Response text:


February 8, 2012






Mr. Tom Ferguson, PG, CHMM, DGSA
Technical Consultant
Council on the Safe Transportation of Hazardous Articles, Inc.
7803 Hill House Court
Fairfax Station, VA 22039


Ref. No. 12-0019


Dear Mr. Ferguson:


This responds to your January 18, 2012 request for written clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to the exceptions provided for portable electronic devices powered by lithium ion batteries carried on an aircraft.  Specifically, you ask whether the aggregate equivalent lithium content (AELC) stated in § 175.10(a)(18)(ii) for up two lithium ion batteries is limited to 25 grams per battery.  


The answer is yes.  Although AELC is not defined in the HMR, its meaning is equivalent to the definition of aggregate lithium content, which is defined as "the sum of the grams of lithium content or equivalent lithium content contained by the cells comprising a battery." § 171.8.  Based on this definition, the 25g limit applies to each battery and not the total between the batteries.  While we revised the text of § 175.10(a)(18)(ii)(formerly subparagraph (17)) in Final Rule 72 FR 44930 (Apr. 9, 2007), our interpretation that each battery may have an AELC up to 25 grams remains the same.  Therefore, a passenger or crew member may carry up to two lithium ion batteries if the AELC of each battery does not exceed 25 grams.  Spare batteries must be carried in carry-on baggage only. 


Thank you for bringing this matter to our attention.  We have created a table outlining the applicability of the exceptions stated in §175.10(a)(18). See Appendix A attached.  We will also consider clarifying this issue in a rulemaking action.  Please contact us if we can be of further assistance.







Dr. Magdy El-Sibaie

Associate Administrator for Hazardous Materials Safety


175.10, 171.8



Appendix A




The following table identifies the exceptions for portable electronic devices stated in

§ 175.10(a)(18):


Type of Battery


(Used to power portable electronic devices, see

  • 175.10(a)(18))

Carry-on Baggage

Checked Baggage


Installed in equipment


Installed in equipment


Lithium ion (Small*) 


(Rechargeable lithium, lithium polymer, LIPO) as used in small consumer

electronics, such as cell phones, cameras,

PDAs, and most laptops.


(* 8 grams or less equivalent lithium content per battery)







(Protected from short circuit)







Lithium ion (Medium*)


(Typically extended-life batteries)


(*More than 8 grams but not more than 25 grams equivalent lithium content per battery)



Limit two (2) batteries per passenger.



Limit two (2) batteries per passenger and protected from short circuit



Limit two (2) batteries per passenger





Lithium metal*


(As used in small consumer electronics such as cameras, LED flashlights, etc.)


(*2 grams or less lithium per battery)






No limit and protected from short circuit








Regulation Sections

Section Subject
171.8 Definitions and abbreviations
175.10 Exceptions for passengers, crewmembers, and air operators