Key facts
- India’s CPCB AQI categories are Good, Satisfactory, Moderate, Poor, Very Poor and Severe.
- India’s NAAQS specify pollutant concentrations and averaging periods.
- AQI categories and NAAQS concentration standards serve different communication and regulatory purposes.
- AQI.news labels its live headline readings as US AQI, not CPCB AQI.
CPCB National AQI categories
CPCB calculates pollutant sub-indices using India-specific concentration breakpoints. The worst qualifying sub-index determines the reported National AQI.
| AQI | Category |
|---|---|
| 0–50 | Good |
| 51–100 | Satisfactory |
| 101–200 | Moderate |
| 201–300 | Poor |
| 301–400 | Very Poor |
| 401–500 | Severe |
Selected Indian NAAQS concentration limits
| Pollutant | Annual limit | Short-term limit |
|---|---|---|
| PM2.5 | 40 µg/m³ | 60 µg/m³ over 24 hours |
| PM10 | 60 µg/m³ | 100 µg/m³ over 24 hours |
| Nitrogen dioxide | 40 µg/m³ | 80 µg/m³ over 24 hours |
| Sulfur dioxide | 50 µg/m³ | 80 µg/m³ over 24 hours |
| Ozone | — | 100 µg/m³ over 8 hours; 180 µg/m³ over 1 hour |
| Carbon monoxide | — | 2 mg/m³ over 8 hours; 4 mg/m³ over 1 hour |
Why AQI.news and CPCB can show different numbers
AQI.news currently labels its headline city value as US AQI. CPCB uses India’s National AQI calculation. Different breakpoints alone can change the index, even before differences in station location, data source, averaging period and update time are considered.
Use CPCB data and procedures for Indian regulatory or official reporting purposes. Use AQI.news as an informational view of live conditions and pollutant trends.
Frequently asked questions
Does AQI.news display CPCB AQI?
No. The current headline city index is explicitly labelled US AQI. CPCB’s National AQI uses different breakpoints and category names.
Is India’s PM2.5 annual standard 40 µg/m³?
Yes. India’s NAAQS lists an annual PM2.5 limit of 40 µg/m³ and a 24-hour limit of 60 µg/m³.
Are WHO guidelines and Indian NAAQS the same?
No. WHO guidelines are global health-based recommendations. India’s NAAQS are national standards with different concentration values and compliance rules.
Sources
This reference was prepared from the following primary public-health and regulatory sources:
- National Air Quality IndexCentral Pollution Control Board, India
- National Ambient Air Quality StandardsCentral Pollution Control Board, India