Published: 06.06.25
New data reveals that firefighters risk an explosion if they use fire blankets to extinguish electric vehicle (EV) fires. DBI’s research supports this conclusion.
It is a really bad idea to fight an EV fire with a fire blanket. This has become clear after two U.S. organizations, the Fire Protection Research Foundation (FPRF) and Fire Safety Research, identified a serious risk of explosion when using fire blankets during EV fire suppression.
When an EV battery catches fire, it produces both heat and flammable gases. Normally, a fire blanket would smother the flames, but during a so-called ‘thermal runaway’ event, the battery continues to emit flammable gases. These gases can accumulate under the blanket and subsequently explode.
The warning from the two U.S. organizations is based on data that is supported by research findings from DBI’s own project, BESAFE, which specifically focuses on the explosion risks associated with battery fires.
“In our controlled experiments, we have documented that gases from a battery fire can explode with a significant shockwave and heat development. Such an explosion can pose a direct threat to firefighters, which is why we recommend using other firefighting methods than fire blankets when an EV is on fire,” says Agata Gallas-Hulin, Battery Program Manager at DBI.
In a previous research project called ELBAS, DBI examined the use of fire blankets for EV fires on board ferries. The conclusion was that fire blankets are highly impractical in confined spaces, making them unsuitable for such situations.
As part of the BESAFE project, DBI conducted a series of tests with lithium-ion battery modules in a custom-built container. Three out of four tests involving thermal runaway in a larger battery followed by gas accumulation in the container resulted in explosions strong enough to force open the container’s pressure relief doors. According to Agata Gallas-Hulin, the closed environment in the container creates conditions comparable to those under a fire blanket placed over a burning EV.
“Our results show that the risk of explosion under those conditions is relatively high. Just like our American colleagues, we therefore recommend that the gases be ventilated, especially in enclosed areas such as underground parking garages,” says Agata Gallas-Hulin.
This recommendation is further supported by another DBI research project BESS (Battery Energy Storage Systems) that mapped international guidelines and practices for fire safety in battery storage facilities. The report emphasized the need to develop tactics and technical solutions for explosion prevention and gas ventilation. It also highlighted the lack of Danish guidelines for gas detection, fire testing, and explosion protection in relation to lithium-ion batteries in larger installations.
