San Francisco Supervisor Bilal Mahmood introduced legislation Tuesday to prohibit the sale of uncertified lithium-ion batteries, which have been blamed for causing numerous fires in the city in recent years.

“This measure is intended to prevent dangerous and fast-moving fires before they start, particularly in dense residential buildings where a single battery failure can threaten dozens of residents,” Mahmood said at Tuesday’s Board of Supervisors meeting.

Lithium-ion batteries are used to power e-bikes and other electronically powered mobility devices. But people can purchase replacement batteries that do not meet the safety standards required for many electronic devices.

These uncertified batteries have become a growing culprit of fires in the city, according to the San Francisco Fire Department. In the last five years, over 120 fires in San Francisco were started by uncertified lithium-ion batteries.

“Lithium-ion batteries are incredibly dangerous if improperly stored or improperly charged,” said Fire Chief Dean Crispen in a social media video with Mahmood.

“Non-UL batteries can be charged over their expected limit where it causes thermal runaway, which creates a large amount of fire and smoke which is toxic to the members of our community as well as the members of our fire department,” Crispen said. 

Non-UL batteries are those that do not have certification from UL, an organization that approves electronic products for meeting safety standards.

In his introduction, Mahmood mentioned a fire that burned an apartment building at 50 Golden Gate Avenue in the Tenderloin neighborhood in December. The fire, which displaced dozens of residents, was caused by a lithium-ion battery. 

“Fires like this spread quickly, produce intense heat and are extremely difficult to extinguish ,” Mahmood said. “But these incidents are not isolated.”

In March, a fire broke out at the Seneca Hotel, a permanent supportive housing facility for formerly unhoused people. The blaze, which sent one person to the hospital, was seemingly caused by a lithium-ion battery.

“Anyone in San Francisco shouldn’t have to be worried about purchasing unsafe batteries or being displaced by a fire due to a neighbor charging one of these they should trust that they are purchasing safe and certified batteries,” Mahmood said.

The measure would make it illegal to buy uncertified lithium-ion batteries in stores and online in San Francisco. It would also give the fire department the authority to cite violators up to $1,000. 

“This proposal will help prevent displacement, protect residents and address a growing fire safety risk before another building is impacted,” Mahmood said.

Alise is a general assignment reporter with a focus on covering government, elections, housing, crime, courts and entertainment in San Francisco and on the Peninsula. Alise is a Bay Area native from San Carlos. She studied history at University of California, Santa Cruz and first started journalism at Skyline College’s school newspaper in San Bruno. She has interned for Bay City News and for Eesti Rahvusringhääling, or Estonian Public Broadcasting. She has covered everything from the removal of former San Mateo County Sheriff Christina Corpus to the divisive battle over the Great Highway on San Francisco’s west side. Please send her any tips.