Pollutants

Time-weighted average

Concentration in ambient air

Method of Measurement

Industrial Areas

Residential, Rural & other Areas

Sensitive Areas

SulphurDioxide (SO₂)

Annual Average*

80 µg/m3

60 µg/m3

15 µg/m3

- Improved West and Geake   Method - Ultraviolet Fluorescence

24 hours**

120 µg/m3

80 µg/m3

30 µg/m3

Oxides of Nitrogen as (NO₂)

Annual Average*

80 µg/m3

60 µg/m3

15 µg/m3

- Jacob & Hochheiser Modified   (Na-Arsenite) Method

24 hours**

120 µg/m3

80 µg/m3

30 µg/m3

- Gas Phase Chemiluminescence’s

Suspended Particulate Matter (SPM)

Annual Average*

360 µg/m3

140 µg/m3

70 µg/m3

- High Volume Sampling, (Average flow rate not less than 1.1 m3/minute).

24 hours**

500 µg/m3

200 µg/m3

100 µg/m3

RespirableParticulate Matter (RPM) (size less than 10 microns)

Annual Average*

120 µg/m3

60 µg/m3

50 µg/m3

- Respirable particulate matter    sampler

24 hours**

150 µg/m3

100 µg/m3

75 µg/m3

Lead (Pb)

Annual Average*

1.0 µg/m3

0.75 µg/m3

0.50 µg/m3

- ASS Method after sampling using EPM 2000 or equivalent Filter paper

24 hours**

1.5 µg/m3

1.00 µg/m3

0.75 µg/m3

.

Ammonia1

Annual Average*

0.1 mg/ m3

0.1 mg/ m3

0.1 mg/m3

.

24 hours**

0.4 mg/ m3

0.4 mg/m3

0.4 mg/m3

.

CarbonMonoxide (CO)

8 hours**

5.0 mg/m3

2.0 mg/m3

1.0 mg/ m3

- Non Dispersive Infra Red (NDIR)

1 hour

10.0 mg/m3

4.0 mg/m3

2.0 mg/m3

Spectroscopy

*

Annual Arithmetic mean of minimum 104 measurements in a year taken twice a week 24 hourly at uniform interval.

**

24 hourly/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.

1.       National Ambient Air Quality Standard: The levels of air quality with an adequate margin of safety, to protect the public health,, vegetation and property.

2.       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.

3.       The standards for H2S and CS2 have been notified seperately vide GSR No. 7, dated December 22, 1998 under Rayon Industry - for details please see Sl. No. 65 of this document.

[S.O. 384(E), Air (Prevention & Control of Pollution) Act, 1981, dated April 11, 1994 ]
[EPA Notification: GSR 176 (E), April 02, 1996]

1. Included vide Notification SO. 955 (E), Air (Prevention & Control of Pollution) Act, 1981 dated October 14, 1998)