Wildfire Smoke

smoky skies

The University’s wildfire smoke safety requirements are based on the Washington State Department of Labor and Industries (L&I) Wildfire Smoke emergency rule. A permanent rule is expected to be adopted in 2023 and this webpage will be updated to reflect any changes at that time.

Fine particles in wildfire smoke can be harmful to health because they can reach lower areas of the lungs. Some individuals are more vulnerable to the effects of air pollution such as those with certain preexisting health conditions. Wildfire smoke may reach our UW locations from various areas both inside and outside of Washington state due to the wildfire smoke patterns.

Outdoor worker protections

The policy and guidance provided by Environmental Health & Safety (EHS&) is based on the Washington State Department of Labor and Industries (L&I) Wildfire Smoke emergency rule. The emergency rule provides protection for personnel working outdoors for more than one hour who may be reasonably expected to be exposed to wildfire smoke.  The rule identifies two action levels to protect personnel when air quality worsens.

For guidance for working indoors during periods of elevated wildfire smoke, refer to the Indoor Air Quality page for more information and instructions for requesting an indoor air quality evaluation.

When AQI reaches 69

When the AQI is at 69 or higher in the location where outdoor work is occurring, the University is responsible for the following:

  1. Communicating wildfire smoke hazards
  2. Providing training regarding wildfire smoke (initially before exposure and annually thereafter).
  3. Providing respiratory protection to employees upon request

Refer to the Responsibilities section of this page for more information.

Refer to the Air quality monitoring section of this page to check the AQI.

When AQI reaches 101

When the AQI is at 101 or higher in the location where outdoor work is occurring, University units must implement these additional safety measures where feasible:

  1. Providing work and/or rest areas in enclosed buildings, structures, or vehicles where the air is effectively filtered
  2. Relocating work indoors or to an outdoor location with a lower AQI
  3. Changing work schedules so that outdoor work can occur when the AQI is lower
  4. Reducing the amount of work that involves physical exertion
  5. Providing additional rest periods
  6. Monitoring personnel for exposure symptoms; refer to the symptoms list in the frequently asked questions section of this page.

Respiratory Protection

When the AQI is at 101 or higher, the University unit is required to provide respirators at no cost to personnel exposed to wildfire smoke.

  • Respirators must be NIOSH-approved devices that effectively protect the wearers from inhalation of particles at the 2.5 micrometers (PM2.5) size, such as N95 disposable filtering facepiece respirators (KN95 respirators not permitted).
  • Respirators are required to be stored, maintained, replaced, and reusable respirators cleaned, so that they do not present a health hazard to the user.

When AQI reaches 555 

When the AQI reaches 555, the airborne concentration of PM2.5 is 555 or more micrograms of gaseous pollutant per cubic meter of ambient air (ug/m3), UW personnel must be enrolled in the respiratory protection program. Personnel must be provided and are required to wear one of the following respirators equipped with high efficiency particulate air filters:

  1. Loose-fitting powered air-purifying respirator; or
  2. Full-facepiece air-purifying respirator; or
  3. Full-facepiece powered air-purifying respirator; or
  4. Other respirators that are at least effective.

The following items do not provide adequate respiratory protection from wildfire smoke:

  • Surgical masks
  • Cloth face coverings
  • Bandanas
  • Scarves


The Wildfire Smoke emergency rule applies to UW work areas where it is reasonably anticipated that personnel may be exposed to wildfire smoke, with the following exemptions.

The Wildfire Smoke emergency rule does not apply when University personnel are:

  • Inside enclosed buildings or structures in which windows, doors, bays, and other exterior openings are kept closed, except when necessary to open doors to enter and exit
  • Inside enclosed vehicles in which the air is filtered by a properly maintained cabin air filter and that windows, doors, and other openings are kept closed except when it is necessary to open doors to enter or exit (buses, light rail, and other enclosed vehicles used for transit systems where doors are frequently opened to board and deboard passengers are not included under the exemption in WAC 296-62-08510 (2)(b))
  • Exposed to outdoor air with an Air Quality Index (AQI) that is 69 or higher for a total of one hour or less during a 24-hour period
  • Engaged in wildland firefighting


Air quality monitoring

The University monitors air quality for our campus locations through the following resources:

University units should not install individual air quality monitors as a general practice. Some exceptions may apply such as for remote locations that do not have representative monitoring stations. Units should consult with EH&S for review and guidance if they anticipate a need for individual air quality monitors.

General precautions

When the AQI is greater than 101, it is recommended that everyone stay indoors and keep windows closed, especially sensitive groups, such as older adults and young children, pregnant women, and those with a breathing or heart condition.

Read more information on the health effects of wildfire smoke and tips for protecting yourself on the Centers for Disease Control and Prevention (CDC) Wildfire Smoke webpage and in the frequently asked questions section below.

Check the Environmental Protection Agency AirNow website for a reliable report of the current and forecasted air quality in your area. AirNow provides the daily AQI, a rating of how clean or polluted the outdoor air is, along with any potential health effects and recommended steps to reduce exposure. 

The best way to protect yourself against the potentially harmful effects of wildfire smoke is to reduce wildfire smoke exposure, for example, by seeking clean air shelters and cleaner air spaces. We recommend keeping windows and doors closed as much as possible to avoid worsening the indoor air quality.

University buildings that use heating, ventilation, and air conditioning (HVAC) systems to filter indoor air typically remove up to 90% of harmful pollutants in wildfire smoke. Indoor portable air cleaners can help supplement mechanical ventilation indoors.

In naturally ventilated buildings (buildings without mechanical HVAC systems), the indoor temperatures may rise due to windows being closed. If the room becomes unbearably hot, portable electric fans and air-conditioning units can be used to cool the space. Check with your unit leadership and the building coordinator to ensure that the facility electrical system can meet the energy demand.


Personnel must be trained on information regarding wildfire smoke before beginning work that exposes the individual to AQI of 69 (PM2.5 levels of 20.5 µg/m3) or higher, and at least annually thereafter.

The Wildfire Smoke Safety Training course is available on the EH&S Training webpage.

Services available

EH&S is available for consultation and may perform a site visit depending on the situation. We are equipped to conduct site measurements for airborne particulate matter concentrations and to provide recommendations.

Visit the Indoor Air Quality page on the EH&S website for more information and instructions for requesting an indoor air quality evaluation.

To request assistance from EH&S please contact us at ehsdept@uw.edu or (206) 543-7388.

Frequently asked questions


More information

Wildfire smoke is a mixture of gases and fine particles from burning trees and plants, buildings, and other material. The primary concern with exposure to wildfire smoke is that it contains fine solid particles (also known as particulate matter) that are 2.5 micrometers (PM2.5) in size or smaller.