By Bay City News Service

Nov. 1 marks the beginning of a four-month period when burning wood will be outlawed on days when weather conditions are expected to cause air pollution to reach unhealthy levels.

The Spare the Air campaign will last until Feb. 28, and is meant to reduce wood smoke on days when weather conditions cause the air to stay still.

Wood smoke is the largest source of wintertime air pollution, according to the Bay Area Air Quality Management District. The combination of wood smoke and still air can lead to air pollution reaching unhealthy levels.

When this is the case, the air quality district will declare a Spare the Air alert, making it illegal to burn wood in fireplaces, pellet stoves and outdoor pits for 24 hours.

The wood-burning rule went into effect last winter, and about 15 to 20 alerts are expected to be issued this season.

First-time alert violators will receive a warning, but repeat offenses will lead to increasingly bigger tickets, starting at $400, the air quality district said.

The alerts will be announced a day before they go into effect.

Bay Area residents can check for alerts by visiting www.baaqmd.gov, calling (877) 4-NO-BURN or signing up for e-mail alerts at www.sparetheair.org.

Residents and businesses that burn wood as their only source of heat are exempt from the law.