National Ambient Air Quality Standards
In one line: The National Ambient Air Quality Standards (NAAQS) set the legal limits for outdoor air pollutants in India.
What they cover
The Central Pollution Control Board notified the current NAAQS in November 2009 under the Air (Prevention and Control of Pollution) Act, 1981. They cover 12 pollutants, including PM10, PM2.5, sulphur dioxide, nitrogen dioxide, ozone, carbon monoxide, lead, ammonia and benzene.
Key limits
The annual average limit is 60 µg/m³ for PM10 and 40 µg/m³ for PM2.5. A city that repeatedly exceeds the standards is called a non-attainment city.
The WHO comparison
WHO's 2021 Air Quality Guidelines set annual guideline values of 15 µg/m³ for PM10 and 5 µg/m³ for PM2.5. India's standards are much looser, which is why many call for a review.
Where to go next
- Particulate matter: PM10 and PM2.5
- National Clean Air Programme
National Ambient Air Quality Standards in the news
- Delhi's September AQI hits a five-year low even as PM2.5 and PM10 levels rose 2 October 2026
India's legal limits for the pollutants in the AQI.
- Swachh Vayu Sarvekshan 2026: Lucknow tops million-plus cities on clean air action 8 September 2026
The legal yardstick for clean air
Previous-year questions on this
- 2021 · GS3 · 10 marks Describe the key points of the revised Global Air Quality Guidelines (AQGs) recently released by the World Health Organisation (WHO). How are these different from its last update in 2005? What…
- 2020 · GS3 · 15 marks What are the key features of the National Clean Air Programme (NCAP) initiated by the Government of India?
- 2016 · Prelims In the cities of our country, which among the following atmospheric gases are normally considered in calculating the value of Air Quality Index? 1. Carbon dioxide 2. Carbon monoxide 3. Nitrogen…