Proposed Wood Smoke Rule Information Background on Model Wood Smoke Ordinance Model Wood Smoke Ordinance Sample of Most Protective Ordinance Adopted	List of EPA Certified Woodburning Appliances Bay Area Cities and Counties that have Adopted Ordinances Reducing Wood Smoke Pamphlet Studies on Health Effects of Wood Smoke EPA Information on Clean Burning Fireplaces & Wood Stoves

The nine counties that surround San Francisco Bay are home to almost seven million residents and an estimated 1.7 million fireplaces and woodstoves. The particulate matter (PM) in the wood smoke from these fireplaces and wood stoves has been a health concern in the Bay Area for many years.

Since the 1980’s, many scientific studies have been published that correlate rising PM levels with serious health effects, such as asthma symptoms, decreased lung function, increased hospital admissions and even premature death.

In response to these concerns and the proliferation of wood heaters in the 1970’s and 80’s, the U.S. Environmental Protection Agency (EPA) set a national PM emission standard for woodstoves at 7.5 grams per hour. Since July 1, 1990, all woodstoves manufactured in the United States have been required to meet this EPA standard. Previously, unregulated woodstoves averaged 60 grams of PM in an hour.

Under certain meteorological conditions – cold, stagnant winter evenings – surface based radiation inversions form quickly in the Bay Area and PM levels rise rapidly. By the 1980’s, wood smoke became the largest area-wide stationary source of particulate matter in the Bay Area. Studies by the Air District indicated that wood smoke was responsible for an average of one-third of the PM10 in the air basin during the winter months and almost 70 percent of the PM10 in Santa Rosa. In addition, wood burning generates carbon monoxide and toxic air pollutants such as benzene and dioxin.