Lithium & Sodium Ion Battery Transportation News:

February 13, 2026 UPDATE

10-FEB-2026 PROPOSED HARMONIZATION RULE ISSUED IN THE FEDERAL REGISTER

US DOT PHMSA finally released the proposed Harmonization Rule in the  February 10, 2026 Federal Register.    The comment period ends on April 13, 2026 and the final rule is anticipated sometime in the summer of 2026.

This is not a final rule, but here are the anticipated significant updates to 49 CFR 171-180 with regards to shipping lithium and sodium ion batteries:

New Proper Shipping Names in the Hazardous Materials Table, 49 CFR 172.101:

UN 3551, Sodium Ion Batteries

UN 3552, Sodium Ion Batteries Contained in Equipment

UN 3552 , Sodium Ion Batteries Packed with Equipment

UN 3556, Vehicle, Lithium Ion Battery Powered

UN 3557, Vehicle, Lithium Metal Battery Powered

UN 3558, Vehicle, Sodium Ion Battery Powered

UN 3171, Battery-Powered Vehicle is to be replaced with UN 3556 and UN 3557, as appropriate.

These proper shipping names align with the IATA Dangerous Goods Regulations and the IMDG Code.   

30 % STATE OF CHARGE / 25% INDICATED BATTERY CAPACITY

Special provision A100 will be updated to align with 2026 IATA DGR rules for battery maximum 30 % State of Charge / 25% indicated battery capacity.   The following entries will be subject to these limits when shipping air transportation:

UN 3481, Lithium Ion Batteries Packed with equipment (if battery watt hour rating > 2.7 Wh)

UN 3556, Vehicle, Lithium Ion Battery Powered (if > 100 Wh)

UN 3558, Vehicle, Sodium Ion Battery Powered (if > 100 Wh)

UN 3480, UN 3481, UN 3551, Shipped per SP A54 or if a prototype (including “…contained in…”).

Note: UN 3480, Lithium Ion Batteries (all battery sizes) are currently subject to the 30 % maximum SoC requirement per SP A100.

For lithium ion and sodium ion batteries not described above, the 30 % maximum state of charge / 25% maximum indicated battery capacity is recommended.

Batteries and cells with a reduced state of charge are less prone to thermal runaway.

SMALL AND MEDIUM BATTERY EXCEPTION

The proposed rule adds sodium ion batteries to the small battery exceptions in 49 CFR 173.185(c).   The sizes and exceptions for sodium ion batteries are identical to those of lithium ion batteries.     

Note IATA has no exceptions for UN 3551, Sodium Ion Batteries.  Per the IATA DGR,  all UN 3551 are fully regulated for air transport.   This conflicts with the proposed rule which allows for a small UN 3551 via all modes of transport.   Let’s see what the final rule looks like….

WHAT TO DO BEFORE THE FINAL RULE IS ISSUED?

Again, this is a proposed rule and the updates are not yet described in 49 CFR 171-180.   In the meantime, if you are shipping sodium ion batteries or battery powered vehicles, follow the 2024 DOT Notice of Enforcement Policy.  Per a December 9, 2024 Notice of Enforcement Policy, DOT PHMSA allows the use of international standards (IATA DGR, IMDG Code) to ship these items domestically until the final harmonization rule is published.

The HAZMATEAM Lithium and Sodium Ion Battery Shipping Guide summarizes the current shipping requirements for all modes of transportation.    Once the final rule is issued, the HAZMATEAM Lithium and Sodium Ion Battery Shipping Guide will be updated and available for download.

JANUARY 1, 2026 UPDATE

IATA DGR  67TH Edition Update

The International Air Transport Association (IATA) 67TH Edition (2026) of the Dangerous Goods Regulations (DGR) took effect on January 1, 2026.   The Sodium Ion Battery and the battery powered vehicle proper shipping names were incorporated into 66th Edition (2025) of the IATA DGR.  

What is new for 2026 with regards to shipping lithium or sodium ion batteries:

30% Maximum State of Charge (SoC) / 25 % Maximum Indicated Battery Capacity

Beginning in 2026 for air transport, the following cells and batteries must not exceed a 30% State of Charge or 25% Indicated Battery Capacity:

    UN 3481, Lithium Ion Batteries Packed with Equipment
    (if the watt hour rating exceeds 2.7 Wh)
    UN 3556, Vehicle, Lithium Ion Battery Powered
    (if the watt hour rating exceeds 100 Wh)
    UN 3556, Vehicle, Lithium Metal Battery Powered
    (if rechargeable and the watt hour rating exceeds 100 Wh)
    UN 3557, Vehicle, Sodium Ion Battery Powered
    (f the watt hour rating exceeds 100 Wh)

Note:   All sizes of UN 3480, Lithium Ion Batteries and UN 3551, Sodium Ion Batteries are subject to the 30 % maximum state of charge limits starting in previous editions of the IATA DGR.

For all other lithium or sodium ion battery entries not described above, the 30% maximum SoC or 25% maximum indicated battery capacity is recommended.

The HAZMATEAM Lithium and Sodium Ion Battery Shipping Guide summarizes these limits.

JUNE 2025 UPDATE

USPS PUBLICATION 52 Update (US Postal Service)

The US Postal Service updated Publication 52 ( Publication 52 - Hazardous, Restricted, and Perishable Mail | Postal Explorer ) to address, most notably, the removal of the telephone number on the lithium battery handling mark.

Several typographical errors related to package marks and labels were identified in Publicaiton 52.  The US Postal Publication 52 Revision: Miscellaneous Policy Updates webpage outlines corrections to the postal hazmat regulations.   Most notably, the page describes correcting the text marking in 349.244 to reflect “secondary” and “lithium ion batteries” as well as removing the telephone number requirement in PI 9D.

Here is a link to the Postal Bulletin article  Publication 52 Revision: Miscellaneous Policy Updates outlining those corrections.  

USPS anticipates an update to Publication 52 in March of 2026 to incorporate these corrections.

The HAZMATEAM Lithium and Sodium Ion Battery Shipping Guide summarizes the correct shipping requirements for shipping per the US Postal Service.


January 29, 2025 UPDATE

The 2025 - 2026 International Civil Aviation Organization's Technical Instructions for the Safe Transport of Dangerous Goods by Air (ICAO Technical Instructions) and Amendment 42-24 of the International Maritime Organization, International Maritime Dangerous Goods Code (IMDG CODE) include several updates to lithium battery transportation regulations.  The 66th Edition (2025) of the International Air Transport Association (IATA) Dangerous Goods Regulations (DGR), which are based on the ICAO Technical Instruction, and Amendment 42-24 of the IMDG Code include the following:

1. Adoption of a new battery chemistry, "Sodium Ion Batteries".  These batteries are rechargeable and are similar to Lithium Ion Batteries.  There are 3 new shipping descriptions:

  a. UN 3551, Sodium Ion Batteries
  b. UN 3552, Sodium Ion Batteries Contained in Equipment
  c. UN 3552, Sodium Ion Batteries Packed with Equipment

For air and vessel transportation there are two sizes of batteries and cells: "small" and "fully regulated".  The sizes are based on the watt hour rating of the cell or battery.  Small cells have a watt hour rating no greater than 20 Wh and small batteries have a watt hour rating no greater than 100 Wh.  There is a noteworthy twist to all of this for air transport of UN 3551 shipped air, there are no "small" cells and batteries.  Therefore, all UN 3551 cells and batteries shipped air transport, regardless of their watt hour rating, are "fully regulated".

2. Adoption of three new shipping descriptions for battery powered vehicles.  A "vehicle" is a self-propelled apparatus designed to carry one or more persons or goods.  The new shipping descriptions are:

  a. UN 3556, Vehicle, Lithium Ion Battery Powered
  b. UN 3557, Vehicle, Lithium Metal Battery Powered
  c. UN 3558, Vehicle, Sodium Ion Battery Powered

These shipping descriptions are to be used instead of UN 3171, Battery-Powered Vehicle.  Although you may continue to used UN 3171 until 31-March 2025.

Most noteworthy battery powered vehicle updates are:

i. Use of the "Class 9 Lithium or Sodium Ion Battery label", instead of the "Class 9 label".

ii. For vessel transport, the exception for package marks/labels and placarding vehicles was eliminated in IMDG Amendment 42-24.  If a vehicle is packaged (the vehicle is not visible) and placed into a freight container, the package must be marked / labeled, and the freight container must be placarded.  This is described in updated IMDG special provisions 961 and 962.

iii. For air transport of UN 3556 and UN 3557, if the battery has a watt hour rating greater than 100 Wh, the battery state of charge "should not" exceed 30% of the rated design capacity or an indicated battery capacity not exceeding 25% capacity.  Effective 1-January 2026, "should not" will be replaced with "must not".  This is described in IATA PI 952.

3. Most notable updates to lithium ion batteries (UN 3480 and UN 3481) and lithium metal batteries (UN 3090 and UN 3091) are as follows:

  a. For air transport of all sizes of UN 3481, Lithium Ion Batteries Packed with Equipment, the battery state of charge "should not" exceed 30% of the rated design capacity.  Effective 1-January 2026, "should not" will be replaced with "must not".  This is described in IATA PI 966.
  b. For air transport of all sizes of UN 3481, Lithium Ion Contained in Equipment, the battery state of charge "should not" exceed 30% of the rated design capacity.  This will remain a recommendation 1-January 2026.  This is described in IATA PI 967.
  c. For air transport of all sizes of UN 3481, Lithium Ion Batteries Contained in Equipment and UN 3091, Lithium Metal Batteries Contained in Equipment, the package must be capable of withstanding, without damage to the cells or batteries contained therein and without any reduction of effectiveness, a force applied to the top surface equivalent to the total weight of the identical packages stacked to a height of 3 m (including the test sample) for a duration of 24 hours (the "stacking test").  This is described in IATA PI 967 & 970.

These updates to the international regulations (ICAO/IATA & IMDG CODE) have not yet been incorporated into 49 CFR 171-180.  However, according to a December 9, 2024 notice from PHMSA, if all or part of transportation is by air or vessel, PHMSA will allow use of these udpated international rules.  For the full text of this notice please refer to:
https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/2024-12/Notice%20of%20Enforcement%20Policy%20Regarding%20International%20Standards%202024.pdf

As for ground transportation, DOT PHMSA has not made any updates to the lithium battery regulations.  Note that DOT PHMSA has not addressed ground shipments of Sodium Ion Batteries or the new battery powered vehicle shipping descriptions.  To ship Sodium Ion Batteries (UN 3551, UN 3552 or UN3558), the December 9, 2025 PHMSA Notice allows the use of the IMDG Code for ground shipments.  As such, all of the ground shipping requirements in the HAZMATEAM Lithium and Sodium Ion Battery Shipping Guide for sodium ion batteries are based on the IMDG Code requirements.  Those who ship lithium ion or lithium metal battery powered vehicles should continue to use "UN 3171, Battery-Powered Vehicles" for ground only shipments until DOT PHMSA issues a final rule sometime in 2025 (mid year??).

DOT PHMSA does not anticipate release of any updates to 49 CFR in the foreseeable future.  Updates will likely occur sometime in mid-year 2025.  Stay tuned....


April 12, 2024 UPDATE

A harmonization final rule, DOT HM-215Q, was issued by DOT PHMSA in the April 10, 2024 FR.  Highlights of this update includes:

1) Removal of the requirement to include a telephone number on the lithium battery handling mark, 49 CFR 173.185 (c)(3).  This update was recently made in the 64th Edition (2023) of IATA Dangerous Goods Regulations and the 41-22 Amendment (2022) of the IMDG Code.  All three regulations allow the old mark, with the telephone number, to be used until December 31, 2026 (DOT: 49 CFR 173.185 (c)(3); IATA DGR: 7.1.5.5; IMDG Code: 5.2.1.10.2).

 2) Removal of the exception in 49 CFR 173.185 (c)(4).  This air transportation exception allowed one package to contain up to 2 small lithium ion batteries (UN 3480) or 2 small lithium metal batteries (UN3090) without a Dangerous Goods Declaration form.  This aligns with the update to the 63rd Edition (2022) of the IATA DGR that eliminated PI 965 Section II and PI 968 Section II.  So all air shipments of any size UN 3480 or UN 3090 must be accompanied by a Dangerous Goods Declaration form.

On April 4, 2024 DOT PHMSA released the electronic versions of the 2024 Emergency Response Guidebook.  Updates relative to lithium batteries include an updated ERG GUIDE 147 (updated fire fighting procedures) and a new section "Considerations for Lithium Battery and Electric Vehicle (EV) Fires".