CENTRAL POLLUTION CONTROL BOARD
National Ambient Air Quality Standards
NOTIFICATION
Delhi, the 11th April, 1994
S.O. 384(E). -The Central Pollution Control Board in exercise of its powers conferred under section 16 (2) (h) of the Air (Prevention and Control of Pollution) Act,1981(14 of 1981) hereby notify the National Ambient Air Quality Standards with immediate effect.
SCHEDULE-1
| Pollutant | Time Weighted average | Concentration in ambient air | Method of measurement | ||
| Industrial Area | Residential. Rural & other areas, | Sensitive Area | |||
| 1 | 2 | 3 | 4 | 5 | 6 |
| Sulphur Dioxide (SO2 ) | Annual Average* | 80 m g/m | 60m g/m | 15 g/m | Improved West and Gacke method |
| 24 hours ** | 120 g/m | 80 g/m | 30g/m | Ultraviolet fluorescence | |
| Oxides of Nitrogen as N02 | Annual Average* | 80 m g/m | 60m g/m | 15 g/m | Jacob & Hochheiser modified ( Na-Arsenite) Method |
| 24 hours ** | 120 g/m | 80 g/m | 30g/m | Gas Phase Chemiluminescence | |
| Suspended Particulate Matter (SPM) | Annual Average* | 360 g/m | 140 g/m | 70 g/m | (Average flow rate not less than 1.1 m /minute) |
| 24 hours ** | 500 g/m | 200 g/m | 100 g/m | ||
| Respirable Particulate matter (size less than10 um)(RPM) | Annual Average* | 120 g/m | 60m g/m | 50m g/m | |
| 24 hours ** | 150m g/m | 100m g/m | 75m g/m | ||
| Lead (Pb) | Annual Average* | 1.0m g/m | 0.75m g/m | 0.50m g/m | AAS Method after sampling using EPM 2000 or equivalent filter paper |
| 24 hours ** | 1.5m g/m | 1.00m g/m | 0.75m g/m | ||
| Carbon Monoxide (CO) | 8 hours | 5.0m g/m | 2.0m g/m | 1.0m g/m | Non dispersive infrared spectroscopy |
| I hour | 10.0m g/m | 4.0m g/m | 2.0m g/m | ||
* Annual Arithmetic mean of minimum 104 measurements in a year taken twice a week 24 hourly at uniform interval
** 24 boudy/8 hourly values should be met 98% of the time in a year. However, 2% of the time, it may exceed but not on two consecutive days.
NOTE:
a. National Ambient Air Quality Standard: The levels of air quality necessary with an adequate margin of safety, to protect the public health, vegetation and property.
b. Whenever and wherever two consecutive values exceeds the limit specified above for the respective category, it would be considered adequate reason to institute regular/continuous monitoring and further investigations.
C. The State Government/State Board shall notify the sensitive and other areas in the respective states within a period of six months from the date of Notification of National Ambient Air Quality Standards.
[F.N.B-33014/4/90]
D. K. BISWAS, Chairman
Last Updated: February 20, 2013
