SF Supervisor Bilal Mahmood and SFFD introduced legislation banning the sale of lithium-ion batteries without a UL certification label due to increased fire risk, giving city agencies authority to penalize retailers and issue fines to consumers who violate the law.

Prompted by the tragic fire in the Tenderloin last December that displaced 45 residents, along with the rise in other battery-related incidents across the city, SF District 5 Supervisor Bilal Mahmood and the SF Fire Department introduced legislation Tuesday prohibiting the sale of uncertified lithium-ion batteries in the city.

The legislation would restrict the sale of lithium-ion batteries by local and online retailers to those with the UL Solutions label, which indicates they meet the required safety standards. According to KGO, it would also allow the fire chief to fine residents up to $1,000 who are in possession of non-certified batteries, while authorizing the city attorney to pursue legal action against merchants who are caught selling them — online or locally.

"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, via NBC Bay Area.

As KQED reports, data from the SF Fire Department shows that structure fires stemming from uncertified batteries have been steadily increasing for several years. Mahmood’s office said in a press release that 120 lithium-ion battery-related incidents occurred in SF from 2024 to 2025, with dozens taking place in or near the Tenderloin.

"Our laws need to catch up with our technology, and this is the first step to do so," Mahmood said, per KGO.

Per KQED, common household devices also contain lithium-ion batteries, including phones, computers, and cordless vacuums, which also pose fire hazards.  

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

While batteries sold in the US are typically UL Solutions-certified, experts say some less reputable, budget e-bike models may sometimes come with uncertified batteries, according to KQED.

“The problem here is not e-bikes and scooters, the problem is when people are using non-UL certified batteries in them,” said Mahmood.

Fire Lt. Mariano Elias said battery fires often ignite with “no real warning” typically starting with a small amount of smoke, leading to sparks, then a big explosion, followed by the release of toxic smoke.

"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," said Crispen in the video.

Elias said battery fires are also difficult to extinguish due to their waterproof casing.

“We’re kind of fighting the casing of the battery,” Elias said, speaking to KQED.

The fire department is also doing its part to increase public awareness surrounding lithium-ion battery safety. Experts recommend precautions such as unplugging e-bikes and scooters when fully charged and avoiding charging while asleep or away. For all devices using lithium-ion batteries, officials also advise strictly using the manufacturer’s charger and charging devices on flat, non-combustible surfaces out of direct sunlight.

Batteries should not be utilized if they pop or hiss, if the battery is visibly bulging, or if the device gets extremely hot.

"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.

Related: Six-Story Apartment Building Next to Golden Gate Theater Goes Up In Flames, 45 Displaced

Image via Citizen app