Burning in fireplaces, uncertified wood stoves and outdoors was banned starting at 2 p.m. Friday in Thurston County.
The burn ban was called because stable weather and cold nights have resulted in air pollution reaching unhealthy levels, according to the Olympia Region Clean Air Agency.
In addition to the bans, no visible smoke is allowed from any woodstove or fireplace, certified or not, beyond a 20-minute start-up period.
A change in weather will be needed to restore cleaner air quality. Warmer temperatures and a chance of rain are forecast starting Monday.
Of particular concern are fine particles released by smoke from wood stoves and fireplaces. The state Department of Health recommends that people who are sensitive to air pollution limit time spent outdoors. Air pollution can trigger asthma attacks, cause difficulty breathing, and make lung and heart problems worse. Air pollution is especially harmful to children, people with heart and lung problems, and adults older than 65.
To determine if your stove is certified, visit orcaa.org.