Seasonal wood burning rule goes into effect Oct. 1

September 26, 2018

Multnomah County’s seasonal wood burning ordinance goes into effect Monday, Oct. 1, and applies through March 1, 2019. During these months, homeowners, renters and businesses in Multnomah County cannot use wood stoves, fireplaces or any outdoor wood burning devices (except for cooking) on days when the air quality is forecasted to be poor.

Burning wood is a leading cause of wintertime air pollution in Multnomah County. In January 2018, the Board of County Commissioners passed an ordinance curtailing burning during the worst air quality days of the year. The rule helps protect people who are most vulnerable to poor air quality — children, senior and people with asthma and other serious breathing conditions. The rule also helps keep the Portland region in compliance with national air quality standards.

"As the county's public health authority, it’s important we find ways to mitigate the impact of air pollution on our residents, especially those who are most vulnerable,” said Commissioner Jessica Vega Pederson, who co-sponsored the ordinance alongside Commissioner Dr. Sharon Meieran. “For most of us, lighting a wood fire is something we enjoy, not something we need to keep warm. This is a simple thing we can do to help keep our neighbors healthy."

The Wood Smoke Ordinance does not apply when:

  • Wood is the household’s sole source of heat.

  • The household income is 60 percent or less than the Oregon median income.

  • A power outage, service interruption or shortage cuts off a primary source of heat.

  • The heating system is overwhelmed by very cold temperatures and cannot produce enough heat.

  • Cooking food using a charcoal grill, smoker or wood fired oven.

What you need to know about the new wood burning ordinance

From Oct. 1 through March 1, officials at Multnomah County Environmental Health will conduct daily forecasting in cooperation with the Department of Environmental Quality and the National Weather Service to identify potential poor air quality days.

When conditions suggest an upcoming inversion (cooler air trapped below warmer air) along with high levels of pollution, Multnomah County will announce a burn restriction by 11 a.m. The curtailment will go into effect at noon and remain in effect for 24 hours unless an extension is warranted.

Officials will publish the curtailment notice on the county’s Wood Smoke website. It will share the notice through social media, including Facebook and Twitter, and push out a notice on Public Alerts (sign up here). Residents can also sign up to receive emails of curtailment notices. 

On most days, a dial posted on the website will point to Green — “Air quality is good. No burn restrictions.”

On some days, the dial might show an arrow pointed to Yellow — “Air quality is moderate,” suggesting a voluntary curtailment for that day.

Rarely, when air quality and weather is very bad, that same dial will point to Red — “Air quality is unhealthy.”

During a curtailment period, residents can report a suspected violation to Environmental Health by calling 503-988-0035 or emailing

Why we need it

Poor air quality disproportionately affects children, seniors and people with existing health conditions. Short-term exposure to wood smoke can aggravate asthma, bronchitis and lung disease. And long-term exposure has been linked to cancer and higher rates of infant mortality.

“Our air quality directly influences these health problems, and wood smoke pollution is a major contributor to poor air quality during the wintertime,” said Commissioner Meieran, who is also an emergency room doctor. “Our wood smoke curtailment ordinance is just one way we can educate the public about the significant health impacts of poor air quality, which can come from woodsmoke, diesel emissions, and other sources.”

The Environmental Protection Agency regulates six air pollutants including particulate matter. The chemicals that contribute to particulate matter are often emitted from wood smoke, power plants, industry and automobiles.

While industrial emissions account for about one percent of the county’s excess cancer risk from air pollution, wood smoke accounts for 11 percent, on par with emissions from cars and commercial trucks. In recent years the county has come close to exceeding its federal cap on particulate matter.

The rule represents an effort to remain in compliance with federal laws as the country's population grows. In recent years the air shed that includes Multnomah County has come close to exceeding its limit on particulate matter 2.5. Washington County, Eugene, Medford, Klamath Falls and Pendleton have all passed similar ordinances as local jurisdictions struggle to remain in compliance with federal air pollution limits.

“It's a modest limit set on people heating their homes with wood but it could have enormous beneficial impacts,” said Jae Douglas, director of Environmental Health. “That's because the three counties that share this airshed are dangerously close to exceeding national air quality standards for small particle pollution.”