SAN FRANCISCO—The city of San Francisco announced they will be phasing out natural gas-powered furnaces and water heaters beginning in 2027 to improve local air quality and public health.

The board of directors of the Bay Area Air Quality Management District adopted rules that will require new water heaters and furnaces to have zero emissions of nitrogen oxides, or NOx after they voted Wednesday, March 15. Exposure to NOx has been linked to respiratory conditions, according to the BAAQMD. The rules do not apply to cooking appliances such as gas stoves.

Roughly two-thirds of San Francisco households use natural gas appliances. The new regulations will prevent up to 85 premature deaths per year and save up to $890 million a year in health-care costs and lost work.

According to the BAAQMD, the rules will apply to water heaters in single-family homes in 2027, furnaces in 2029, and multifamily and commercial water heaters in 2031. The compliance dates are meant to allow availability of zero-emitting equipment to increase and costs to come down.