The meaning of the blue flag:

PM2.5 0 – 15 µg./m³ = very good air quality  

The meaning of the green flag:

PM2.5 15.1 – 25 µg./m³ = good air quality 

The meaning of the yellow flag:

PM2.5 25.1 – 37.5 µg./m³ = moderate air quality 

The meaning of the orange flag:

PM2.5 37.6 – 75 µg./m³ = Unhealthy air quality for sensitive groups

The meaning of the red flag:

PM2.5 75.1 µg./m³ or higher = Unhealthy air quality for all groups

Countermeasure 

For levels between 37.6-75 µg./m³

It is predicted that there will be an upward trend. Educational institution directors can order closure for no more than 3 days at a time. District directors can order closure for no more than 7 days at a time. 

For levels higher than 75 µg./m³

The dust situation is expected to continue unabated and will likely continue to increase for 3 consecutive days. Educational institution directors can order closure for no more than 15 days at a time.

For levels higher than 75 µg./m³ Over 2-3 district areas 

The dust situation is expected to continue unabated and will likely continue to increase for 3 consecutive days. It depends on the discretion of the Governor of Bangkok to issue an order to close schools for an indefinite time.

You can follow air quality information at www.airbkk.com or AirBKK application