Toronto Fire Chief Jim Jessop stated that a room can reach flashover in about five minutes when it catches fire. Flashover occurs when all items in a room hit their maximum temperature, resulting in the entire room being engulfed in flames with no chance of survival. However, Jessop highlighted that a lithium-ion battery fire, which has seen a significant increase in incidents in Toronto since 2022, can escalate to flashover within 90 seconds. As of August 19, Toronto Fire reported 86 lithium-ion battery fires, compared to 91 in all of 2025.
The chief emphasized the dire consequences if a fire blocks the sole exit in a room, reducing the chances of survival for occupants. Lithium-ion batteries, commonly found in various devices like phones and power tools, are often involved in fires due to damage or overcharging, particularly in micromobility devices such as e-bikes and e-scooters.
During a recent fire on George Street, firefighters discovered multiple micromobility devices in one unit. Jessop and his team highlighted the challenges posed by these batteries, including their unpredictable behavior, high heat, and release of toxic chemicals. The intensity of fires can vary based on the battery’s charge level, posing risks of explosions and projectile hazards for responding crews.
Jessop called for swift action from federal and provincial authorities to regulate these batteries. Health Canada and the Ontario fire marshal are considering implementing regulations and changes to ensure safer batteries are sold in the country. Jessop stressed the importance of setting standards for batteries as a crucial initial step.
Randy Narine, president of Clean Core Research, explained that lithium-ion battery fires result from a gradual buildup of heat leading to gas release and eventual sustained flames, known as thermal runaway. Mistreatment of batteries, either physically or electronically, can trigger fires. Narine pointed out that using improper chargers or subjecting batteries to physical stress, such as pressure from riders on e-scooters, can lead to hazardous situations.
Early signs of thermal runaway include white smoke emitting from the battery, containing toxic chemicals like hydrogen fluoride. Narine highlighted the dangers associated with this smoke, emphasizing the need for caution. While awaiting regulatory changes, Toronto Fire is focusing on educating the public on safe practices like proper charging and disposal to prevent battery-related incidents. Jessop emphasized the urgency of accelerating these efforts to enhance public safety.