Metro Vancouver's annual seasonal prohibition on the use of appliances such as wood stoves and fireplaces under the Residential Indoor Wood Burning bylaw begins on May 15 and lasts until September 15.The seasonal restriction came into effect last year as part of phased measures under the bylaw to protect the public from the effects of wood smoke during a time when indoor heating is used less frequently. The seasonal prohibition does not apply when wood burning is the only source of heat in a residence, in the case of emergencies, and for those living off-grid in rural parts of the region.The Residential Indoor Wood Burning Emission Regulation Bylaw aims to reduce emissions from indoor wood burning appliances through the use of best burning practices and lower-emitting wood burning appliances. Requirements for burners to declare the use of best burning practices and register their wood-burning appliances are coming into effect between mid-2022 and 2025. Residential wood smoke is the most significant source of fine particulate matter (PM2.5) emissions in the region, contributing more than a quarter of the annual total PM2.5 emissions. Due to their small size, these tiny particles can enter buildings from the outside air. When breathed in, the particles penetrate deep into a person's lungs and bloodstream and can be harmful to health, particularly for infants, the elderly, and people with diabetes, lung disease, or heart disease. Metro Vancouver operates an extensive air quality monitoring network with 31 permanent stations and one mobile unit. The regional district sets air quality objectives, responds to air quality complaints, and enforces bylaws pertaining to air emissions from industry, businesses and residences. Residents can monitor regional air quality using AirMap.