A record sixth straight Spare the Air alert was called for Friday in the Bay Area as cold stagnant air spurs a continued ban on burning wood fires.

The Bay Area Air Quality District announced it is extending the burning ban another 24 hours on Friday because of forecasts of unhealthy air quality. Spare the Air alerts also were called on Sunday through Thursday.

"Unfortunately, with the weather system that has been in place for the past week, wood smoke pollution in the Bay Area continues to sit over the region," Jack Broadbent, the air district's executive officer, said in a written statement. "The current weather trend is preventing the built-up air pollution from clearing out in the Bay Area."

The alert triggers a ban on burning wood fires in fireplaces, fireplace inserts, stoves, fire pits and other devices .

Before this month, the previous record was four consecutive Spare the Air alerts. Friday will be the 10th Spare the Air alert of this cold season in the Bay Area.

The air district will consider temporary exemptions to people with broken heaters. People are advised to call 877-4-NOBURN to seek an exemption.

There are fines for those who break the no-burn ban. First time offenders must pay a $100 fine or take an online smoke education course. The fine is $500 for a second offense.

Contact Denis Cuff at 925-943-8267. Follow him at Twitter.com/deniscuff