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Air Pollution

Learn about air pollution issues in Washington County and how to protect your health when air quality is poor.

Much of Washington County sits in a valley shaped like a bowl. Sometimes pollution sinks down into our valley and gets stuck. Pollen, wildfires and smog all contribute to bad air quality. When air quality is bad, it’s important to protect your health.

As Oregon’s summer season gets long, hotter and drier, the chance of wildfires increases. Pollen and mold counts are also increasing as our climate changes. Some things that contribute to air pollution in Washington County include emissions from diesel construction equipment and road vehicles, wildfire smoke, and wood burning in the winter.

People who already have heart or lung problems (like asthma or high blood pressure), children, older adults, outdoor workers and pregnant people are affected more by bad air quality and should take extra steps to protect themselves. Above all else, community is critical to preventing illness and death in the face of climate change. When the air quality is bad, be sure to check on your friends, family and neighbors and share these resources with them.

Find a clean air space

Washington County clean air centers

Multnomah County clean air centers

Clackamas County clean air centers

Learn More

Wildfire smoke safety

Check the air quality near you

There are many great resources for monitoring local air quality in your area. More people are purchasing air quality monitoring devices to use in their own homes or neighborhoods, but the quality and accuracy of these devices can vary. We recommend using a reputable website like or the OR DEQ Air Quality Monitoring site to monitor air quality in your area.

Download these guides to learn more

How to protect your health from wildfire smoke

Older adults, children, pregnant people, outdoor workers, and people who already have heart or lung problems like asthma or heart disease are at a higher risk for becoming seriously ill from air pollution. People in these categories should be extra careful when air pollution is bad.

Stay informed

Know the air quality near you using or the OR DEQ Air Quality Monitoring site.

Avoid smoky air

  • Stay inside as much as possible.
  • If you have to be outdoors, wear a mask, like a KN-95, to protect your lungs from harmful particles.
  • Avoid doing physical activity outdoors like playing sports or yard work.

Keep indoor air clean

  • Keep windows and doors closed and only open them again when air quality is good.
  • Tape up large gaps in doors, windows, vents or fireplaces that let smoke in.
  • Get an air purifier with a HEPA filter or make your own using a box fan and MERV 8 or higher filter. See below.
  • Change air conditioning and air purifier filters frequently. Filters rated MERV 8 or higher are recommended.
  • Set home or car air conditioners to recirculate mode.
  • Don’t smoke, use candles, or vacuum when air quality is bad.
  • Avoid frying or boiling foods.

Protect your pets

Smoke can have a serious impact on your pets. It can irritate their eyes, lungs and heart, just as it can for humans. Keep your pets indoors and safe from smoke as much as possible. If you notice a change in behavior from them, such as red or watery eyes, trouble breathing, tiredness, or reduced appetite or thirst, call your veterinarian.

Seek professional health care

If you have a health condition and your symptoms get worse around smoke, contact your health care provider for prevention and treatment advice.

Call 911 if you or someone else has serious symptoms like trouble breathing.

Download these guides for more information

Learn to make your own air purifier

Apply to receive an air purifier

If you're an Oregon Health Plan (OHP) member, you might be able to receive an air purifier through their Flexible Services Program. Learn more.

Build your low-cost filter fan with:

• Box fan

• A furnace filter (20” x 20”, rated MERV 13 or FPR 10 or MPR 1500-1900)

• Tape (painter or duct)


  1. Tape the filter against the back of the fan.
  2. The arrows on the filter should point toward the front of the fan.
  3. Turn the fan on.


  • To create a “cleaner air room,” use the filter fan in the room you spend the most time in.
  • Close all windows and doors in the room while the filter fan is in use.
  • Run the filter fan for at least 10-15 minutes.
  • Position the filter fan away from walls and big objects where no one will trip over it.
  • Replace the filter every three months or when it looks dirty/brown.

Download the guide or watch these videos for instructions

Get more information on wildfire smoke safety

Oregon Health Authority has detailed resources in 10 languages. Visit their Wildfire and Smoke Preparedness webpage for more information.

Smoke from woodstoves, outdoor fires and yard debris burning

Our air must meet federal standards for fine particle pollution under the Clean Air Act. During the fall and winter, Washington County sees a rise in pollution caused by wood burning. In addition to having negative health impacts, if we don’t meet federal air quality standards, large businesses in the county can face restrictions which can impact growth and jobs in our community. Help protect our community by burning safely and responsibly.

If you burn wood indoors at home

Bookmark this page to check air quality status November 1 through March 1 before you burn, or call the Air Quality Status Line at 503-846-8744.

Sign up for Public Alerts to receive a text, email or phone call when a “red day alert” is issued for poor air quality. Be sure to select "red day alerts" under "additional notifications" when you sign up.

Rules for burning wood at home

Air quality rules and woodstove burning restrictions

Air quality rules

From November 1 to March 1, Washington County monitors air quality and may issue a "red day alert" that applies to anyone who lives in unincorporated Washington County. The cities of Hillsboro and Cornelius have adopted similar ordinances, so this notification system applies to those residents as well. A red day alert means that air quality is unhealthy and that no fireplace or wood stove use is allowed, unless exempt (see exemptions below).

We will also tell you when the air quality is unhealthy for sensitive groups. On those days, we ask that people voluntarily refrain from burning wood unless they absolutely need to for heat.

Typically, most days the air quality is good and no wood burning restrictions are in place.

Exceptions to burning restrictions

  • Households that rely on wood burning as their only source of heat.
  • Households that qualify as low-income.
  • When there is an interruption in utility service (electricity or natural gas).
  • When a household's primary heating system is temporarily not working (no more than 120 days).
  • The ordinance does not restrict the use of pellet stoves.
  • The ordinance does not restrict burning between March 2 and October 31.

In addition, outdoor burning of yard debris is prohibited year-round in unincorporated areas of Washington County that are also within the Metropolitan Service District Boundary.

Burning yard debris or wood outside at your home

Burning yard debris is not allowed in unincorporated areas of Washington County that are eligible for yard debris pickup from a waste hauler. On this map, if the area you live in is shaded in blue, burning yard debris is not allowed. If you live in an area of the county that is not shaded in blue, check with your local fire department or the Department of Environmental Quality for more information about open burning rules in your area.

  • The rules do not apply to recreational wood fires like camp fires, fire pits or chimineas.
  • The rules do not apply to agricultural burning.

Alternatives to burning yard debris

  • Use curbside yard debris rolling carts, cans and bags from your garbage collector.
  • Recycle paper and cardboard in your curbside recycling container or take it to a drop-off recycling center.
  • Compost yard debris and kitchen scraps at home.
  • Take yard debris to a drop-off center.
  • Rent or use a wood chipper to make chips for mulch and compost.
  • Reuse old lumber or donate it to a drop-off reuse center.
  • Take hazardous materials to a household hazardous waste facility.

If you don't have another way to get rid of your yard debris

You may be able to get a hardship permit. Hardship permits are only available March 1 through June 15 and October 1 through December 15.

Download the application here. (PDF 292.74 KB)

How to reduce wood smoke

Check local air quality conditions before you burn every time at or the OR DEQ Air Quality Monitoring site.

Heat your home with cleaner heat sources like an electric or ductless heat pump, gas stove or insert, gas furnace, or pellet stove or insert. Visit the Wood Stove Exchange program for more information on trading in an old wood stove.

Burn only dry split and well-seasoned wood. For more tips on burning cleaner, visit the EPA’s burn-wise program.

File a yard debris or wood burning complaint

You can file a complaint for residential burning of yard debris or the use of a fireplace, wood stove or wood stove insert during a “red day alert” issued by the county.

Get help replacing your old wood stove

Washington County is offering rebates of $1,500-$4,000 when you replace your old wood stove with a new stove, insert or other heating system. Some households will qualify for a full-cost replacement. We also have the occasional wood stove turn-in event where you can get paid to bring in your old wood stove. Learn more through our Woodstove Exchange Program.