Ambient Air Quality Standards

Ambient air quality standards are the legal limits of air pollutants during given period of time defined by authority. They are allowable level of pollutants in environment to the population or ecological system.

National Ambient air quality standards (NAAQS) for ambient air quality monitoring (NAAQM) established by Central pollution Control Board (CPCB) of India in November 2009 for the ambient air quality of entire country. Addition to this CPCB has notified the quality of air in its notification.

Learn more Ambient Air Quality Guidelines

Categories for Ambient Air Quality Standards

For this Purpose Entire country was divided into three categories

  • Industrial Areas
  • Residential and Rural Area
  • Sensitive Area (Schools, Hospitals etc.)Ambient Air Quality Standards

Main objective of to define Ambient air quality standards is to protect Human health. For normal populations as well as children, elder adult, Individuals suffering from respiratory diseases like asthma etc. Also to provide uniform quality for all, irrespective of land use purpose, across all country.

Standards for Major Four Parameters like SPM, SO2, CO and NOx only are defined. Ambient air quality standards become strict as we go from category 1 to 3.

There are total 12 parameters identified by CPCB affect human health, which are to be measured across all country by same method to keep uniformity.

Ambient Air Quality Standards

Below are the National ambient Air Quality Standards (NAAQS) dated 16.11.2009


POLLUTANTSTime Weighted AvgConcentration of Ambient Air
Industrial AreaResidential Rural and other areaSensitive areaMethod of Measurement
Sulphur Dioxide (SO2)Annual Average80 gm/m360 gm/m315 gm/m3Improved west and Gacke Method
24 hrs120 gm/m380 gm/m330 gm/m3Ultraviolet fluorescence
Oxides of Nitrogen (NO2)Annual Average80 gm/m360 gm/m315 gm/m3Jacab Hochheister modified (Na-Arsentire method
24 hrs120 gm/m380 gm/m330 gm/m3Gas Phase Chemilumine Scene
Suspended Particulate Matter (SPM)Annual Average360 gm/m3140 gm/m370 gm/m3High Volume sampling (average flow rate not less than 1.1 m3/minute)
24 hrs500 gm/m3200 gm/m3100 gm/m3
Respirable Particulate Matter (size < 10 m) RPMAnnual Average120 gm/m360 gm/m350 gm/m3Respirable particulate matter sampler
24 hrs150 gm/m3100 gm/m375 gm/m3
Lead as PbAnnual Average1.0 gm/m30.75 gm/m30.50 gm/m3AAS method after sampling using EPM 2000 or equivalent filter paper
24 hrs1.5 gm/m31.0 gm/m30.75 gm/m3
Carbon Monoxide8 hrs5.0mgm/m32.0mgm/m31.0mgm/m3Non disbersive infrared spectroscopy
1 hour10.0mgm/m34.0mgm/m32.0mgm/m3



Annual Average means arithmetic mean for at least 104 readings in a year twice a week 24 hourly at uniform level

24 Hrs Average means 24 hourly, 8 hourly or 1 hourly ambient air quality monitoring values, as applicable, shall be complied with 98% of time. For remaining 2% days it can exceed but not on two consecutive days.

If ambient air quality monitoring results on two consecutive days of monitoring exceeds limits specified above for mentioned category, then that company should carry out regular/non-stop monitoring till further notice. Government Publish these results via newspapers TV or radio in regular intervals for major cities. For layman’s understanding there are some changes while showing it to them. They convert it into Air Quality index.  it is just a ratio of actual pollutants levels present to permitted limits by pollution control board.

Read Here Air Quality monitoring

Ambient Air Quality is Part of Environmental Monitoring.


Related posts:

Leave a Reply

Your email address will not be published. Required fields are marked *