FOREST RANCH, Calif. -

Firefighters are getting more control over the Web Fire burning in Butte County.

As of Wednesday morning, CAL FIRE said the fire had burned 375 acres and was 60 percent contained.

Fire crews made significant progress overnight in gaining containment. Work will continue to build and strengthen control lines in the steep terrain.

The fire was reported Monday at 1:11 p.m. in the Web Hollow area west of Highway 32 and northwest of Forest Ranch.  

No structures are threatened.

The cause of the fire remains under investigation.

CAL FIRE said full containment of the fire is expected by Friday, August 1 at 8 p.m.

Some valley and foothill locations are currently being impacted by smoke from the Web Fire, resulting
in poor air quality conditions, especially in the morning. This is expected to continue for several days until the fire is extinguished.

The major air pollutant of concern is fine particulate matter also known as PM2.5.  The young, elderly and those with respiratory conditions may experience more serious symptoms which may include, but are not limited to coughing, watery and itchy eyes, and difficulty in breathing.

Wednesday's air quality index (AQI) level in Chico is forecast to be unhealthy for sensitive groups.  People with heart or lung disease, older adults, and children should reduce prolonged or heavy exertion.