In January 2021, the NTSB issued a safety recommendation to 22 electric vehicle manufacturers based on an NTSB safety report, "Safety Risks to Emergency Responders from Lithium-Ion Battery Fires in Electric Vehicles."
NTSB investigators found automaker emergency response guides were not up to par. The government also found gaps in safety standards and research regarding high-speed crashes which involve electric vehicles equipped with lithium-ion batteries.
Federal investigators opened investigations following electric vehicle crashes because the high-powered lithium-ion batteries can shock first responders. Damaged battery cells can also suffer from thermal runaway, a phrase used to describe uncontrolled thermal and battery pressure temperatures.
But damaged electric vehicle batteries may have "stranded" energy that can reignite fires days after a crash. In a recent case of a Tesla electric vehicle crash, the batteries reignited at the salvage yard three weeks after the original fire.
The fire was finally extinguished by placing the Tesla into a pit of water.
"Honda, Hyundai, Mitsubishi, Porsche, Proterra, Van Hool, Volkswagen and Volvo have successfully completed the actions asked for in the NTSB recommendation," the NTSB said.
There are another 12 manufacturers making progress on the federal safety recommendation: BMW, BYD, Stellantis (Chrysler), Ford, General Motors, Gillig, Kia, Mercedes-Benz, Nissan, Subaru, Tesla and Toyota.
The NTSB said Nova Bus Corporation and Karma Automotive haven't responded.