Lithium-Ion Battery Incidents and Their Impact on Aviation Safety
For the first time, UL Standards & Engagement is publicly sharing data from its Thermal Runaway Incident Program, to support awareness and prevention of thermal runaway in aviation.
Why do lithium batteries catch fire on planes?
Lithium-ion batteries, while efficient and widely used, can present safety hazards if damaged, improperly charged, poorly manufactured, or counterfeit. Devices containing these batteries should not be stored in checked luggage. Instead, keeping all lithium-ion battery-powered devices within arm’s reach can sharply reduce the risk of an incident occurring. Devices powered by lithium-ion batteries are generally safest in the hands of the owner, in the cabin of the aircraft where the device can be observed for signs of thermal runaway such as heat and smoke. If these signs are noticed early, airline crews have procedures to contain the device and prevent further damage to the aircraft or injury to passengers.
What impact does public awareness of lithium-ion batteries have on aviation safety?
Rechargeable devices like phones, laptops, tablets, and portable power packs, are integral to the air travel experience. Still, consumer awareness of products that rely on lithium-ion batteries and the risks they may carry is concerningly low. These knowledge gaps, combined with the notion of assumed safety, have serious implications for aviation safety. Read more.
The Thermal Runaway Incident Program
Through ULSE’s Thermal Runaway Incident Program, we are collaborating with airline industry dangerous goods and hazardous materials professionals to closely examine data on lithium battery incidents and better understand the scale and complexity of this growing aviation safety issue. Developed with, and for, airline industry dangerous goods professionals, TRIP is a secure, voluntary system for aviation-related lithium battery incidents. Leading passenger and cargo carriers participate in TRIP, voluntarily reporting incidents to the TRIP database and participating in program summits to solve for risk. Learn more.
How can standards help mitigate battery-related fires on planes?
Our standard, UL 5800, Battery Fire Containment Products, provides fire test and performance criteria to evaluate fire containment products used to contain lithium-ion battery fires and the related effects during flight. These containment products are intended to be used by authorized personnel on commercial, private and military aviation for portable electronic devices such as cellphones, tablets and laptops that are on fire or at risk of catching on fire in the cockpit or cabin. Learn more.
Related Resources
- Addressing Lithium-Ion Battery Risks
- UL 5800 is available for purchase on ShopULstandards.com or can be viewed online for free using the Digital View functionality (registration required)
Key Findings
Incidents are at the highest point in five years of data collection. Incidents rose 28% over the past five years, from 2019-2023. There are an average of two thermal runaway incidents reported in the TRIP database each week. While on the rise, with approximately 180,000 flights in U.S. airspace per week, it is still highly unlikely to experience a thermal runaway incident. (Source: UL Standards & Engagement)
The average passenger brings four rechargeable devices on board. Most common items include smartphones (82%), laptops (41%), wireless headphones (39%), and tablets (36%). E-cigarettes were responsible for the most incidents in 2023, with 35% of reported incidents attributed to vaping devices on passenger flights, followed by power banks, representing another 16% of incidents. (Source: UL Standards & Engagement)
Most incidents happen on the aircraft with devices that are stored near the passenger’s seat. Almost nine out of ten (87%) incidents are reported on the aircraft, with the remaining 13% occurring when baggage and personal items are on the move. On the aircraft, thermal runaway incidents occur in or around the passenger’s seat nearly 60% of the time. (Source: UL Standards & Engagement)
The vast majority of incidents are addressed before reaching the fire or explosion stage of thermal runaway. Most (85%) incidents in 2023 were addressed when batteries showed warning signs such as overheating and smoking prior to entering full thermal runaway. While only 15% of incidents resulted in fire or explosion, the speed in which thermal runaway can develop means that the events in the majority could have been more serious had the issue not been addressed quickly. (Source: UL Standards & Engagement)
Rechargeable devices are being packed in checked luggage. The devices that were most cited in thermal runaway incidents in 2023 were also the two most frequently put in checked luggage, according to passengers surveyed. More than a quarter (27%) of travelers reported checking portable chargers, and another 27% said they checked e-cigarettes. Devices that enter thermal runaway in checked baggage cannot be accessed by crew while in flight, and fires may not be detected as quickly in the cargo hold as they would be in the cabin. (Source: UL Standards & Engagement)
