Study Warns of Severe Chemical Lung Injury Following Indoor E-Bike Battery Fires
A 2026 medical study published in the Journal of Plastic, Reconstructive & Aesthetic Surgery describes two devastating inhalation injuries following indoor e-bike lithium-ion battery fires.
The cases demonstrate that these incidents can expose occupants to more than heat, flames and conventional smoke. Burning lithium-ion batteries can also release hydrogen fluoride and other toxic gases capable of causing severe chemical injury to the lungs.
Two Patients, One Death and Lasting Lung Damage
Both fires occurred while an e-bike battery was charging indoors.
- The first patient suffered burns to 32% of his body and developed acute respiratory distress syndrome and severe chemical pneumonitis. He required mechanical ventilation for 45 days. Two years later, his ability to exercise remained significantly reduced.
- The second patient suffered burns to 44% of his body. His respiratory condition deteriorated rapidly despite intensive treatment, specialized ventilation and extracorporeal membrane oxygenation. Imaging showed catastrophic destruction of both lungs. He died after 18 days of ECMO support, even though his external burns had healed.
These cases show that the internal chemical injury caused by a battery fire may become more serious than the visible burn injuries.
Why Hydrogen Fluoride Is a Concern
Lithium-ion battery failure can release hydrogen fluoride, which forms hydrofluoric acid when it contacts moisture. This substance can penetrate tissue, bind with calcium and cause local tissue destruction and systemic toxicity.
The study states that hydrogen fluoride emissions during battery failure may range from 20 to 200 milligrams per watt-hour. E-bike batteries can store approximately 250 to 3,000 watt-hours of energy. In a confined room, toxic concentrations could therefore develop quickly and exceed levels considered immediately dangerous to life or health.
This finding reinforces the particular danger of charging e-bikes and similar battery-powered devices inside apartments, bedrooms, hallways and other enclosed spaces.
Early Findings May Understate the Injury
One of the study’s most important observations is that severe respiratory failure can develop even when an early examination of the airways does not appear catastrophic.
In the second case, the patient’s lower airways initially appeared relatively preserved. His condition nevertheless progressed to widespread pulmonary destruction.
The authors identified several early warning signs in the two patients:
- Respiratory deterioration disproportionate to the initial airway findings
- Mildly reduced blood-calcium levels
- Abnormal blood-coagulation results
- Airway swelling
- Progressive respiratory acidosis
- Worsening bilateral lung abnormalities on medical imaging
The authors recommend that clinicians maintain a high level of suspicion for toxic chemical exposure after a lithium-ion battery fire, particularly when it occurs indoors.
Implications for Emergency Services
This study has important implications across the emergency-response system.
Fire services should recognize that occupants and responders may face a toxic chemical exposure in addition to heat and ordinary smoke inhalation.
Paramedics and emergency departments should clearly document that an incident involved a lithium-ion battery and watch for respiratory deterioration that appears disproportionate to the initial examination.
Police and 911 communicators can help ensure that battery involvement and indoor charging are identified and relayed to responding agencies.
Hospitals and burn units may need to consider chemical pneumonitis and possible hydrogen fluoride exposure when assessing patients from enclosed-space battery fires.
The study also supports the need for respiratory protection, scene ventilation, exposure documentation, medical monitoring and effective information transfer between fire, EMS and hospital personnel.
An Emerging Clinical Risk
There is currently no established treatment protocol specifically for hydrogen fluoride inhalation injury from lithium-ion battery fires. The authors advocate early calcium monitoring and intensive respiratory support. They also suggest that nebulized calcium gluconate may warrant consideration, while acknowledging that direct evidence supporting this treatment for inhalation exposure remains limited.
This publication is a two-patient case report, so its findings should not be interpreted as representing every e-bike or lithium-ion battery fire. Hydrogen fluoride exposure was not directly quantified in the patients. Nevertheless, the clinical patterns, laboratory findings and extensive lung damage raise a serious and credible warning requiring further medical research and responder education.
CESAT Perspective
Lithium-ion battery incidents must be approached as multi-hazard events. The danger does not end when the flames are extinguished or when visible burns have been treated.
These cases reinforce the need for coordinated training involving 911 personnel, police, firefighters, paramedics, emergency departments and burn specialists. Battery involvement should be identified early, communicated throughout the patient handoff and incorporated into exposure monitoring and treatment decisions.
For emergency personnel, the central lesson is straightforward:
After an enclosed-space lithium-ion battery fire, respiratory failure that appears disproportionate to the initial smoke-inhalation findings may indicate a serious chemical injury.
Study Reference
Keelan, S., Murphy, M., Abrahams, M., Shelley, O., and Kennedy, S. “Hydrofluoric acid inhalation injury after electric bike battery fire.” Journal of Plastic, Reconstructive & Aesthetic Surgery, Volume 118, 2026, pages 424–427. DOI: 10.1016/j.bjps.2026.04.035.