Why Fire Blankets May Be Risky in Electric Vehicle Fires: New Research Findings

Experiments conducted by FPRF and FSRI show that:

• Fire blankets successfully eliminate open flames by cutting off oxygen.
• However, thermal runaway inside the EV battery pack continues even after visible fire is extinguished.
• This process releases flammable gases, which accumulate under the blanket.
• In some scenarios, the built-up gases have exploded, especially when oxygen is reintroduced.

“Suppressing the flame does not mean eliminating the threat,” the joint report emphasizes.

The research highlights four commonly tested EV firefighting approaches:

1. Standard water hose stream
2. Water with injected agent
3. Electric vehicle fire blankets
4. Specialized firefighting appliances

Among them, the use of fire blankets raised the most concern due to invisible yet volatile gas accumulation. These findings reinforce the urgent need for updated EV fire response training and revised best practices for first responders.

Both organizations are continuing their investigations:

• FPRF’s report on EV firefighting tactics will be shared at the NFPA Conference & Expo in June 2025, with the full version available in the fall at nfpa.org/foundation.
• FSRI’s findings will be detailed in their own upcoming EV safety report at fsri.org.

These efforts aim to provide data-driven guidance for firefighters and safety professionals as electric vehicles become increasingly common in residential and commercial environments.

The FPRF, the research affiliate of NFPA, is a nonprofit committed to advancing fire safety science and developing practical solutions through collaborative research.

Part of UL Research Institutes, FSRI focuses on resolving modern fire safety challenges by providing tools, data, and education to improve tactical decisions and public awareness.

One of the most dramatic incidents featured in the video occurred in Colorado, where firefighters were unaware that gases from a burning plug-in hybrid were building pressure inside a garage. The resulting explosion blew the doors off their tracks, nearly hitting a firefighter and knocking others off their feet.

This process, called off-gassing, often precedes a battery explosion. Without thermal cameras or gas sensors, first responders may not recognize the threat until it’s too late.

This joint notice is a timely wake-up call for fire services worldwide. While fire blankets may appear to provide quick control, they can also conceal life-threatening hazards when lithium-ion batteries are involved.

The safest response starts with informed tactics—backed by science.