Wednesday, March 15, 2023

The Air District Board of Directors has adopted amendments to Regulation 9, Rules 4 and 6, to eliminate emissions of nitrogen oxides, or NOx, from residential and commercial natural gas furnaces and water heaters in the Bay Area by requiring new appliances to be zero-NOx. 

Spare the Air Status


Emissions from natural gas building appliances account for a similar amount of NOx pollution as passenger vehicles in the Bay Area. As a group, they are one of the largest emitters of nitrogen oxides of all stationary sources of air pollution, which the Air District regulates.

The rule amendments would apply only to new appliances and do not mandate the immediate change out of existing appliances, nor will they apply to appliances used for cooking, such as gas stoves. NOx-emitting natural gas furnaces and water heaters will be phased out over time, beginning with water heaters in 2027.

The rule amendments will improve overall regional air quality from the outdoor venting of these appliances, lower exposure to particulate matter, particularly in communities of color, and avoid up to $890 million per year in health impacts due to air pollution exposure.

NOx emissions impact local and regional air quality and contribute to the formation of ozone and particulate matter, or PM2.5. Exposure to NOx has been linked to coughing, wheezing, difficulty breathing, asthma, and increased susceptibility to respiratory infections. Exposure to particulate matter has been linked to asthma and other respiratory conditions, neurological disease, heart attack, stroke, lung cancer, and premature death. The new amendments will safeguard public health against the hazards of these pollutants and prevent an estimated 85 premature deaths, as well as dozens of new asthma cases, in the Bay Area each year.

The Air District released a draft environmental impact report and solicited comments to the proposed rule amendments through a 45-day public comment period, which ended on February 6, 2023.

Compliance dates are between 2027 and 2031, dependent on equipment type, use, and size.  To learn more about the building appliance rules and compliance timelines, visit the Building Appliances Rule Amendments web page.

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Last Updated: 3/16/2023