NATIONAL AMBIENT AIR QUALITY STANDARDS*

Pollutant Time Weighted Average           Concentration in Ambient Air
Industrial Area Residential, Rural and other Sensitive Area 
Sulphur Dioxide (SO2)   Annual

  24 hours

    80 µg/m3

 120 µg/m3

   60 µg/m3

  80 µg/m3

  15 µg/m3

 30 µg/m3
Oxides of Nitrogen (NO2)   Annual

  24 hours

    80 µg/m3

 120 µg/m3

   60 µg/m3

  80 µg/m3

   15 µg/m3

  30 µg/m3
Suspended Particulate Matter (SPM)   Annual  

  24 hours

   360 µg/m3

  500 µg/m3

  140 µg/m3

 200 µg/m3

   70 µg/m3

 100 µg/m3

Respirable ** Particulate Matter (RPM) 

Annual 

24 hours  

  120 µg/m3

  150 µg/m3

    60 µg/m3

  100 µg/m3

   50 µg/m3

  75 µg/m3
Lead (pb)   Annual

  24 hours

   1.0 µg/m3

  1.5 µg/m3

    0.75 µg/m3

   1.00 µg/m3

   0.50 µg/m3

   0.75 µg/m3
Carbon Monoxide(CO)   8 hours

  1 hour

   5.0 µg/m3

 10.0 µg/m3

   2.0 µg/m3

  4.0 µg/m3

   1.0 µg/m3

  2.0 µg/m3

* Ministry of Environment and Forests, Government of India notification,1994

** Particle size less than 10 µm