The key message?

?Bay Area residents must check before they burn,? district Executive Officer Jack Broadbent said.

This year?s Winter Spare the Air Day season, which began Nov. 1 and runs through February, subjects those within the district to fines if they burn on bad air days.

Changes this year include better advance notification of when restrictions are in place; the district will declare any no-burn day by 2 p.m. the previous day.

The ban period will run 24 hours, from midnight of that day to midnight the following night, said Ana Sandoval, senior policy advisor for the district.

Last year the declarations were made the same day.

?What we were finding was that people weren?t getting the word in time, or they had already started their fires,? Sandoval said.

The district, whose boundary north of Windsor divides northern Sonoma County as well as most Russian River and coast communities into a separate district, also has added to an array of systems developed to alert residents to burn ban days.

The shift is part of a broad, two-year effort to educate the public about the Wood Burning Rule adopted in July 2008 making it illegal to burn wood, pressed logs, pellets and other solid fuels on days forecast to have particularly bad air quality.

There are exemptions for residents who have no other source of heat, no natural gas or electrical service, or who use the wood as cooking fuel.

For others, the district expects to declare from 15 to 20 no-burn days during the year. Fireplaces, pellet stoves, wood stoves, inserts and outdoor fire pits are all part of the ban.

The law also requires those who use stoves and fireplaces to burn cleanly year-round, using dry, seasoned wood and refraining from burning leaves, garbage or other materials that would produce excessive smoke.

The penalty for failing to comply with the restrictions is $400 and is imposed after a resident has received one warning, district officials said.

The rule is enforced by inspectors assigned around the district who respond to residences when complaints about fires or excessive smoke are made, Sandoval said.

Though 254 warning letters were issued for violations last year, only one resident was fined for a second violation ? a Santa Rosa resident, Sandoval said.

She attributed broad compliance to widespread awareness of the law enacted to diminish the toxins and particulate matter that are produced by wood fires and which account for a third of winter air pollution. The pollution is linked to asthma, bronchitis and lung disease, and is considered especially harmful for children and the elderly, district officials said.

On cold days with little air circulation, smoke lingers. Such conditions prompted the district to declare 11 Winter Spare the Air Days in winter 2008/2009.

Don Ricke, who sells pressed logs made from recycled wood products through his Sebastopol company, Two Men With a Big Truck, said awareness of the restrictions is high.

But he said many of his customers have no other source of heat in their houses, many of which were converted from summer vacation homes.

Efforts this year are largely to reinforce the message and make it easier for people to know which days are ban days.