FAIRBANKS — An ordinance that would restrict wood and coal burning when the air is unhealthy goes before the Fairbanks North Star Borough Assembly for a vote on Thursday.

The ordinance would trigger a new system of air quality alerts, with the worst—stage three—leading to a prohibition on wood and coal burning when particulate pollution hits 75 micrograms per cubic meter. That happened in North Pole last year 25 times, according to the borough’s air quality manager.