Table 3.
National AQI classes, range, health impacts and health breakpoints for the seven pollutants (scale: 0–500).
| AQI class (Range) |
Health impact | PM10 24 h (μg/m3) |
PM2.5 24 h (μg/m3) |
SO2 24 h (μg/m3) |
NO2 24 h (μg/m3) |
O3 8 h (μg/m3) |
CO 8 h (mg/m3) |
NH3 24 h (μg/m3) |
|---|---|---|---|---|---|---|---|---|
| Concentration range | ||||||||
| Good (0–50) | Minimal impact | 0–50 | 0–30 | 0–40 | 0–40 | 0–50 | 0–1 | 0–200 |
| Satisfactory (51–100) | Minor breathing discomfort to sensitive people | 51–100 | 31–60 | 41–80 | 41–80 | 51–100 | 1.1–2 | 201–400 |
| Moderately polluted (101–200) | Breathing discomfort to the people with lung disease | 101–250 | 61–90 | 81–380 | 81–180 | 101–168 | 2.1–10 | 401–800 |
| Poor (201–300) | Breathing discomfort to people on prolonged exposure | 251–350 | 91–120 | 381–800 | 181–280 | 169–208 | 10–17 | 801–1200 |
| Very poor (301–400) | Respiratory illness to the people on prolonged exposure | 351–430 | 121–250 | 801–1600 | 281–400 | 209–748* | 17–34 | 1200–1800 |
| Severe (401–500) | Respiratory illness to the people on prolonged exposure | >430 | >250 | >1600 | >400 | >748 | >34 | >1800 |