Responding to Fires that Include Energy Storage Systems Using Lithium-ion Battery Technology are a New and Evolving Hazard

The International Association of Fire Fighters (IAFF), in partnership with UL Solutions and the Underwriters Laboratory’s Fire Safety Research Institute, released “Considerations for Fire Service Response to Residential Battery Energy Storage System Incidents.” PDF The report, based on 4 large-scale tests sponsored by the U.S. Department of Energy, includes considerations for response to fires that include energy storage systems (ESS) using lithium-ion battery technology.

The report captures results from a baseline test and 3 tests using a mock-up of a residential lithium-ion battery ESS installed in a representative 2-car garage and discusses several critical size-up and tactical considerations that were developed based on the findings. Key takeaways include:

Fire growth rate

The impact of lithium-ion battery involvement on fire growth rate suggests that when firefighters respond to these incidents, they should consider:

• Rapid fire growth.
• Explosion hazards.
• The potential for unburned battery gas in a ventilation-limited fire to increase the flammability of smoke, which can increase risk of backdraft.

Thermal runaway

Lithium-ion batteries may go into thermal runaway in the absence of active fire. Thermal runaway can be recognized as distinct white or gray battery gas leaking from the structure and forming low-hanging clouds. If there is a suspected case of batteries in thermal runaway and there are no indicators of a concurrent fire, a structure should not be approached or entered to take gas meter measurements. In all cases when lithium-ion thermal runaways are suspected, hose lines should be pre-deployed, charged and ready for operations before ventilation or entry.

Explosion hazard

This begins the instant batteries undergo thermal runaway and release gas without burning. The timing and severity of a battery gas explosion is unpredictable. Firefighters are at greatest risk for explosion hazards in the driveway and at doors, windows and other vent points. To avoid this hazard, the fire apparatus should not be parked in front of the garage door.

Confirmation of battery involvement

There are no reliable visual, thermal imaging or portable gas meter indicators to confirm battery involvement in a room and contents fire.

Personal protective equipment (PPE)

Full structural PPE (Level D ensemble) with full self-contained breathing apparatus should be donned before performing size-up.

The IAFF, UL Solutions and FSRI will continue to work on this project to develop training materials. Access the report PDF on the IAFF’s website.