Transporting batteries, particularly lithium-ion and the emerging sodium-ion types, poses significant safety challenges. A key concern is the risk of thermal runaway, where a battery’s temperature rapidly increases, potentially leading to fires or explosions. Aircraft cargo holds, even when airtight, may not effectively suppress such fires, as the intense heat can cause batteries to reignite. Innovative solutions, like using glass pearls, are being explored to absorb heat and mitigate these risks. The energy required to melt the pearls helps reduce the heat generated during a thermal runaway event, providing an additional layer of safety.
The International Air Transport Association (IATA) and the International Civil Aviation Organization (ICAO) have implemented several critical updates to their 2025 Dangerous Goods Regulations to ensure the continued safe transport of lithium ion, lithium metal and sodium ion batteries. This blog explains the key changes.
Key Changes in the 2025 Regulations
- Introduction of New UN Numbers and Packing Instructions for Sodium-Ion Batteries
With sodium-ion batteries emerging as an alternative to lithium-ion technology, the 2025 regulations introduce two new UN numbers and three new proper shipping names for sodium-ion batteries.
- UN 3551,Sodium ion batteries
- UN 3552,Sodium ion batteries contained in equipment
- UN 3552, Sodium ion batteries packed with equipment
In addition, three packing instructions for these new entries have been added.
These packing instructions mirror those for lithium-ion batteries, making it easier for shippers to adapt while maintaining high safety standards.
As with lithium batteries, sodium-ion cells and batteries must undergo rigorous performance testing to verify their safety. A test summary must be made available by manufacturers and distributors, enabling shippers to confirm compliance with these requirements.
While sodium-ion batteries are a promising alternative to lithium-ion batteries, they are not yet widely used in consumer products. Their primary applications are in industrial energy storage systems, such as power grids and data centers. The inclusion of sodium-ion batteries in the 2025 regulations is a proactive step, ensuring safety protocols are in place as their usage becomes more widespread.
- Updates for Electric Vehicle Batteries
Additionally, three new UN numbers for electric vehicles are introduced, and the associated packing instruction is revised to ensure compliance with updated safety standards. The new UN numbers include:
- UN 3556: Vehicle lithium ion battery powered
- UN 3557: Vehicle lithium metal battery powered
- UN 3558: Vehicle sodium ion battery powered
These updates address the safe transport of electric and hybrid vehicles, reflecting the growing adoption of electric mobility technologies.
- Renaming the Battery Mark and Miscellaneous Battery Label
To include sodium-ion batteries, the following changes have been made:
- The Battery Mark: Now applies to both lithium batteries and sodium-ion batteries. This mark is required on packages containing small batteries that qualify for certain exemptions.
- The Class 9 Miscellaneous Battery Label: Renamed to explicitly cover both lithium batteries and sodium-ion batteries. This label is mandatory for shipments requiring a Shipper’s Declaration for Dangerous Goods.
- State-of-Charge (SoC) Requirements for Lithium-Ion and Sodium-Ion Batteries
To reduce the risk of thermal runaway lithium-ion and sodium-ion batteries must be shipped at a state-of-charge not exceeding 30% of their rated capacity when shipped loose.
For vehicles and lithium batteries contained in or packed with equipment, the batteries should be offered for transport at a state of charge not exceeding 30% or 25% of their indicated battery capacity. This requirement will become mandatory on January 1, 2026, with a few exceptions specified in the regulations.
Conclusion
The 2025 updates to battery transport regulations highlight the importance of adapting to new technologies while maintaining stringent safety standards. By introducing UN numbers and packing instructions for sodium-ion batteries, adding UN numbers for electric vehicle batteries, renaming key marks and labels, and enforcing strict SoC requirements, IATA and ICAO ensure the safe transport of batteries.
Understanding and complying with these regulations is not just a legal obligation. It is important to note that all batteries are regulated, although some smaller ones may benefit from exceptions.
