SAN FRANCISCO (CBS SF) – The Bay Area Air Quality Management District has extended its Winter Spare the Air Alert into and wood burning ban into Tuesday, with unhealthy air quality expected to continue.

Officials said a high pressure system over Northern California will act like a lid, trapping smoke at ground level, the air district said. The worst air quality impacts are likely to be in the Santa Clara Valley, with winds expected to be light, along with cold temperatures overnight.

“In the midst of a pandemic, it is more important than ever for residents to protect their respiratory health by not burning wood,” said Air District executive officer Jack Broadbent.

The Air District says wood smoke contains carcinogenic substances such as particulate matter and carbon monoxide, which has been linked to serious respiratory illnesses and increased heart attack risk. Fine particulates in the smoke is especially harmful for children, the elderly and those with respiratory conditions, officials said.

During the Winter Spare The Air alert, businesses and residents are not allowed to use fireplaces, wood stoves, pellet stoves or outdoor fire pits to burn wood, manufactured fire logs or any other solid fuel. Natural gas, propane or electric fireplaces are allowed.

Exemptions are available for homes where the only source of heat is a wood stove or a fireplace, but devices must be EPA certified or registered with the Air District.

First time violators of the wood burning ban can take a course or receive a $100 ticket, while repeat violations are subject to fines $500 and up. Residents seeking to file a complaint or seeking more information are asked to call 1-877-4NO-BURN or visit baaqmd.gov.