DETROIT (AP) – Electric vehicle fires pose safety risks for first responders and manufacturers’ guidelines on how to deal with them are inadequate, according to US researchers.
There are also gaps in industry safety standards and the investigation of high voltage lithium-ion battery fires, especially in rapid, severe crashes, the National Transportation Safety Board said Wednesday.
The agency, which has no enforcement powers and can only make recommendations, called on manufacturers to write vehicle-specific response guides for fighting battery fires and limiting chemical thermal overcurrent and re-ignition. The guidelines should also include information on how to safely store vehicles with damaged lithium-ion batteries.
The recommendations come at a time when carmakers are introducing multiple new models of electric vehicles, with many in the industry seeing a tipping point in switching from gasoline to cleaner electricity.
The agency also asked firefighters and auto towing associations in its Wednesday report to educate members about fire risks and how to manage the energy left in the battery after a crash, and how to safely store a vehicle with a damaged battery.
And it is asking the National Highway Traffic Safety Administration to include the availability of an emergency guide when calculating five-star vehicle safety ratings.
The NHTSA should also form a coalition to explore ways to de-energize batteries and reduce the dangers of thermal runaway, a chemical reaction that causes uncontrolled battery temperature and pressure increase.
The NTSB has begun investigating battery fires following crashes and fires in Lake Forest and Mountain View, California, and in Ft. Lauderdale, Florida, in 2017 and 2018. It also investigated a non-crash fire in West Hollywood, California. Three of the batteries came back on after the fires were out.
All four vehicles are made by Tesla, the top-selling electric vehicle manufacturer in the US.
“The risks of electric shock and re-ignition / fire of the battery stem from the ‘stranded’ energy left in a damaged battery,” the agency said.
In the August 2017 fire in Lake Forest, a Tesla Model X battery caught fire after the vehicle exited the road and crashed into a residential garage at high speed. Thomas Barth, an NTSB engineer and highway researcher, said in a video from an agency that firefighters poured thousands of gallons of water on the roof of the vehicle. “They were unaware that they had to direct water to the battery compartment under the car to cool the battery and stop the reaction that caused the fire,” he said.
In an 80-page report, the NTSB wrote that a review of 36 manufacturers’ emergency response guidelines found that they all had ways to reduce the risk of high-voltage shock, including methods of disconnecting the battery. But none of the guides talked about mitigating the risk of energy stored in the batteries, such as procedures to minimize re-ignition or instructions on where and how to spray water to cool the batteries, the agency said.
One way to deal with damaged batteries is to pull them out of the vehicle and soak them in a salt water bath to discharge the energy, the NTSB wrote.
The National Fire Protection Association, which provides training for first responders and towing companies, said it has already followed up on most of the NTSB recommendations. Andrew Klock, chief manager of emerging issues, says the group has provided training on how to put out battery fires, then jack up vehicles, and dip the batteries in water to limit re-ignition.
The NFPA has trained about 250,000 first responders, but there are 1.2 million firefighters nationwide, Klock said.
In a statement, NHTSA said it launched a battery safety initiative last week to address growing concerns about electric vehicles and fires from structures lit by batteries. Under the initiative, the agency will analyze data, investigate fires and supervise investigations of electric vehicle accidents, the agency said.
The Alliance for Automotive Innovation, a major auto maker trade group, said it will review its recommendations and work with fire associations, NHTSA, the Society of Automotive Engineers and others to improve safety.
Messages were left on Wednesday asking for comment from Tesla and the National Fire Protection Association.