09/14/2026
How is Wildfire Smoke Measured? (Save these links!)
PM2.5 is particularly dangerous for people who work outdoor jobs in construction, agriculture, and other industries where workers have a higher physiological workload during the day.
It’s measured as very fine particulate matter called PM2.5 — very small particles 2.5 micrometers (µm) or smaller. Air samples are evaluated for the weight of the particles in a volume of air, or micrograms per cubic meter (μg/m3): PM2.5.
Online tools you can use to check the current air quality include:
- Washington’s Air Monitoring Network from the Department of Ecology. (https://airqualitymap.ecology.wa.gov/)
- Washington Smoke Information blog from government agencies and Tribes. (https://wasmoke.blogspot.com/)
- Fire and Smoke Map from the U.S. Environmental Protection Agency (EPA). (https://fire.airnow.gov/)
These tools can help you protect workers, monitor smoke conditions, and meet employer requirements.