How to limit your exposure to wildfire smoke indoors

It’s already a record breaking wildfire season in the Pacific Northwest, and with wildfires comes smoke. Exposure to smoke can cause adverse health impacts for everyone, but especially for children, the elderly and people with existing health conditions. Symptoms from wildfire smoke exposure include a cough, scratchy throat, headache, stinging eyes and congestion. 

There are a lot of things you can do to limit your exposure to wildfire smoke indoors to keep your family safe:

1. Keep your windows and doors closed. 
2. Limit activities indoors that can increase air pollution including smoking/vaping, burning candles or incense, frying food, using aerosols, using a gas stove, vacuuming (unless your vacuum has a HEPA filter).
3. Stop smoke from entering your home.
   • If you have an HVAC system, turn off the fresh air intake setting and set your system to “on” instead of “auto.” It’s recommended to use a MERV 13 filter or higher. Check and replace filters often.
   • If you have a heat pump, turn off the fresh air intake or “economizer” switches if your system has one and turn on “recirculation mode”, if applicable. If you have a ductless mini-split, it does not pull in air from outside.
   • If you have an evaporative cooler, you can completely cover the outside air intakes with 4 inch MERV13 furnace filters. If this isn’t possible, use the evaporative cooler sparingly, since it can bring more smoke inside.
   • If you have a window AC unit, close the outdoor damper. If this isn’t possible do not use the unit. Make sure the seal between the unit and the window is tight.
   • If you have a portable air conditioner with a single hose, it exhausts indoor air outside, which can pull smoky air indoors, so use sparingly. If your unit has two hoses, it does a better job exhausting the outdoor air. For either, be sure to completely seal any gaps around the window installation kit.
   • If it is hot and smoky and you do not have a safe way to cool your home, consider finding a cooling center nearby.
4. Use a high efficiency filter to remove particulates from the air. Make sure the filter is clean and run it at the highest speed for as often as possible. If you do not have access to one, you can make your own temporary one. Here’s a quick guide from the Washington Department of Ecology.
5. Have a supply of N95 respirator masks on hand if you need to go outside when it’s smoky out. Here is more information on how and when to use them.

If you still have questions, the Environmental Protection Agency has more resources on their website to help you navigate wildfires and indoor air quality.

Stay safe.