UL Research Institutes Releases New Report Examining the Fire Safety Hazards of E-mobility Devices on Passenger Railcars

Research studied lithium-ion battery fire impact and outlines recommendations for improved public safety

COLUMBIA, Md., May 21, 2026 /PRNewswire/ -- UL Research Institutes' Fire Safety Research Institute today announced a new report, Recommendations to Improve Passenger Railcar Safety During Electric Micromobility Vehicle Fires. The new report examines the railcar conditions during lithium-ion battery thermal runaway incidents involving e-mobility devices, such as a standing e-scooter, e-bike or seated e-scooter.

The Fire Safety Research Institute conducted experiments using a full-size, intercity passenger railcar and measured heat exposure, toxic gas concentrations and their impact on passenger safety and evacuation conditions. The Fire Department of the City of New York and Christiana Fire Company provided support and suppression for the experiments.

The report found that passengers within 10 feet of a burning e-mobility device could be quickly incapacitated by thermal exposure from the severe fire these devices can produce, and all passengers also risk incapacitation by exposure to the smoke from that quickly growing fire. Most people would not recognize the imminent danger of a failing battery until smoke suddenly starts to vent from the device. Once flaming began in the devices, smoke reached the other side of the railcar within 30 seconds, and full visibility was lost in under four minutes. Typically, devices smoked for only a few seconds before igniting. Toxic gas measurements determined that conditions would have significantly hampered tenability between 3 and a half minutes and 7 minutes after ignition.

"We've already seen e-mobility thermal runaway incidents on public transportation networks in cities, including New York City, Toronto and Madrid," said Adam Barowy, principal research engineer for Fire Safety Research Institute. "Our hope is that by understanding the hazard in one setting, we can apply our insights in other similar settings and prevent dangerous situations in the future."

The use of e-mobility devices has been on the rise as the technology has become more readily available and urban commuters use the devices for first- and last-mile transportation.

The report concludes with considerations for improved passenger safety, including:

• Railcar design: Physical modifications could create separation between device storage and passenger seating.
• Device policies: Require safety certified devices, consider restrictions on the size of e-mobility devices allowed on board, and specify designated storage areas.
• Transit staff training: Provide lithium-ion battery-specific training to passenger railroad staff.
• Public education: Help riders understand and reduce the risks before they board.

Fire Safety Research Institutes is focused on understanding how lithium-ion batteries - whether in e-mobility devices or electric vehicles - change the fire environment so that first and second responders can respond safely and mitigate the hazard, and the public can minimize hazards arising from personal use. Learn more at fsri.org.

About Fire Safety Research Institute

UL Research Institutes' Fire Safety Research Institute advances fire science and fire safety knowledge to reduce risk, save lives, and protect property. We conduct rigorous research, outreach, and education in collaboration with the fire service, fire safety professionals, policymakers, communities, and an international network of partners. Together, we develop tools, resources, and strategies that improve fire safety outcomes worldwide. To learn more, visit fsri.org. Follow FSRI on Instagram, Facebook, and LinkedIn.

About UL Research Institutes

UL Research Institutes is a nonprofit research organization dedicated to advancing public safety through scientific discovery. Since 1894, our research has advanced our mission toward a safer, more secure and sustainable future. Focused on global risks from fire mitigation and air quality to safe energy storage and digital privacy, we conduct rigorous independent research, analyze safety data and partner with experts to uncover and act on existing and emerging risks to human safety. Discover more at UL.org.

SOURCE UL Research Institutes