How dangerous is Very Unhealthy AQI?
Very Unhealthy AQI (201-300) triggers health warnings for the entire population. Everyone will likely experience health effects. Sensitive groups may experience serious effects. Minimize all outdoor exposure.
Should I stay completely indoors?
Yes, staying indoors as much as possible is strongly recommended. Run HEPA air purifiers, seal windows, and avoid activities that generate indoor pollutants like cooking on gas stoves or lighting candles.
When does AQI reach Very Unhealthy levels in the US?
Very Unhealthy AQI is relatively rare but occurs during major wildfire events (common in western states), severe smog episodes, and industrial disasters. Some cities may experience a few days per year in this range.
Should I wear a mask outdoors at this AQI?
Yes, an N95 or KN95 respirator mask is strongly recommended if you must go outside. Surgical masks and cloth masks do NOT filter fine particulate matter effectively. Ensure the mask fits tightly with no gaps.
What emergency steps should I take?
Seal your home, run air purifiers, avoid vacuum cleaning which stirs up particles, check on elderly neighbors, keep rescue medications accessible, and monitor local health department advisories. Consider temporarily relocating if possible.