Table 1.

IITM-SAFAR air quality descriptors, AQI numeric values, and corresponding air pollution concentration thresholds and temporal averaging periods [95,140].

Air Quality Descriptor	AQI Value	PM2.5 (μg/m3) 24-hr Average	PM10 (μg/m3) 24-hr Average	O3 (ppb) 8-hr Average	NO2 (ppb) 24-hr Average	CO (ppm) 24-hr Average
Good	0–100	0–60	0–100	0–50	0–43	0–1.7
Moderate	101–200	61–90	101–250	51–84	44–96	1.8–8.7
Poor	201–300	91–120	251–350	85–104	97–149	8.8–14.8
Very Poor	301–400	121–250	351–430	105–374	150–213	14.9–29.7
Severe	401–500	251–350	431–550	375–450	214–750	29.8–40