January 13, 2025: Thermal runaway incidents on aircraft have soared to a five-year high, according to a new report by the safety and compliance organization Underwriters Laboratories (UL).
Incidents increased by nearly 30% between 2019 and 2023 with an average of two reported a week to UL Standards & Engagement’s (ULSE) thermal runaway incident program.
In a report released on December 18, UL said the proliferation of lithium battery-powered personal electronic devices was at the heart of the problem.
UL said its research indicated that while 97% of crew understand the potential for battery fires and explosions on aircraft, only 46% think airlines effectively communicate these risks to passengers.
This perception aligns with findings from separate ULSE surveys of US airline passengers, which revealed that many remain largely unaware of the risks associated with these batteries, UL said.
“This striking dichotomy between crew knowledge and passenger awareness highlights the critical need for improved passenger education through prominent signage, verbal announcements, and more detailed safety briefings.”
Airline crew members are largely confident in their ability to identify and respond to battery incidents, thanks to clear procedures and training, but availability of fire containment devices to suppress li-ion battery fires is not universal, the report said.
“A notable minority of crew members still lack full confidence that passenger safety is assured — highlighting critical areas for further improvement.”
UL said only 27% of cabin crew surveyed feel “very confident” about passenger safety from potential battery incidents, while 55% are merely “somewhat confident”, which the organization said is “a lukewarm assurance at best for such a critical safety concern”.
Alarmingly, 18% lack confidence altogether, feeling either “not very confident” or “not confident at all”.
Meanwhile, UL said 25% of passengers admit they store one or more rechargeable products in their checked luggage, a practice that heightens the risk of thermal runaway incidents going unnoticed and escalating beyond control.
