Smog AQI Health Advisory
Enter an Air Quality Index (AQI) number to get the official EPA category, a color-coded gauge, health effects, and practical safety steps for the general public, children, elderly people and outdoor workers.
050100150200300500
Health effects
Precautions
Mask guidance
Home tips
Frequently asked questions
The AQI is a 0 to 500 scale that reports how clean or polluted the air is. Higher numbers mean worse air quality and greater health concern.
Smog is caused by a mix of fine particles (PM2.5) and ground-level ozone from vehicle exhaust, industrial emissions, crop residue burning, brick kilns and dust.
A well-fitted N95 or FFP2 mask filters fine particles. Surgical and cloth masks give only limited protection against smog particles.
When the AQI is in the Unhealthy for Sensitive Groups range (101 - 150) or worse, limit children outdoor play and keep them indoors when the air is Unhealthy or worse.
No. It is a general health guide based on the EPA AQI scale. If you have asthma, heart disease or breathing trouble, follow your doctor advice.
Yes, it is completely free to use online with no signup needed.