How to remain safe from hazardous haze
The air quality in the Bay Area has remained at unhealthy levels for several days after the huge Camp Fire broke out in Butte County. Sensitive groups — seniors, young children and people with chronic heart or lung conditions — are especially at risk. Here’s what the indoor air quality experts at Lawrence Berkeley National Laboratory recommend doing: Stay indoors as much as possible, with the windows closed.
Refrain from vigorous activities that would increase your rate of breathing and intake of air pollutants.
Wear a N95 or P100 respirator mask when you’re outside. They can substantially reduce your intake of fine particles when worn properly (fitted to your face with two straps).
If you have a continuous ventilation system in your home, such as an exhaust fan in the laundry room, turn it off. If you have a central forced air system, use it in “fan on” mode.
Check or change air filters in your home, usually located at the return grille or air unit. MERV (Minimum Efficiency Reporting Value) is the industry rating system used by many filter manufacturers. The higher the number, the stronger the filtration. See a list of Berkeley Lab’s recommended filters here.
Consider getting a portable air purifier for your home. They work best in a room that is closed off from other parts of the house, like a bedroom, where you can create a “clean air zone.” For large spaces and open floor plans, use multiple units. When picking a purifier, look for Clean Air Delivery Rate (CADR), a measure of how many cubic feet of clean air the device produces each minute. It’s recommended that an air purifier has a CADR of at least two-thirds of the room’s square footage: a 120-square-foot room should have an air purifier with a CADR of 80 or above. The Association of Home Appliance Manufacturers has a searchable directory of purifiers that includes CADR data.
If you’re driving in a car, set the ventilation to recirculation mode at medium or high. If the air quality seems to be getting worse, turn it off.
If you’re looking to get indoors, San Francisco has designated several air shelters. They are: San Francisco Main Public Library (100 Larkin St.), Mission Bay Library (960 Fourth St.), Westfield San Francisco Centre mall (865 Market St.), Chinatown Branch Library (1135 Powell St.) and Glen Park Branch Library (2825 Diamond St.).