Purple Air Quality
100+ Unhealthy for Sensitive Groups
150+ Unhealthy (Precautions Required)
200+ Very Unhealthy (Critical Conditions)
300+ Hazardous (Life Threatening)
Air quality guideline is an annual mean concentration guideline for particulate matter from the World Health Organization. The guideline stipulates that PM2.5 not exceed 10 μg/m3 annual mean, or 25 μg/m3 24-hour mean; and that PM10 not exceed 20 μg/m3 annual mean, or 50 μg/m3 24-hour mean.