The Australian National Air Quality Standard

The standard is officially called "National Environment Protection (Ambient Air Quality) Measure".

The standard has the following tables:

Table 1: Standards for Pollutants

Column 1
Item
Column 2
Pollutant
Column 3
Averaging Period
Column 4
Maximum concentration standard
Column 5
Maximum allowable exceedances
1 Carbon Monoxide 8 hours 9.0 ppm 1 day a year
2 Nitrogen Dioxide 1 hour
1 year
0.12ppm
0.03ppm
1 day a year
None
3 Photochemical oxidants (as ozone) 1 hour
4 hours
0.10 ppm
0.08 ppm
1 day a year
1 day a year
4 Sulfur dioxide 1 hour
1 day
1 year
0.20 ppm
0.08 ppm
0.02ppm
1 day a year
1 day a year
None
5 Lead 1 year 50 μg/m3 None
6 Particles as PM10 1 day
1 year
50 μg/m3
25 μg/m3
None
None
7 Particles as PM2.5 1 day
1 year
25 μg/m3
8 μg/m3
None
None

Table 2: Goal for Particles as PM2.5 by 2025

Column 1
Pollutant
Column 2
Averaging period
Column 3
Maximum concentration
Particles as PM2.5 1 day
1 year
20 μg/m3 by 2025
7 μg/m3 by 2025

Authority of the Standard

The standard records that it "was made under secion 20 of the National Environment Protection Council Act 1994 (Cwlth), National Environment Protection Council (New South Wales) Act 1995 (NSW), National Environment Protection Council (Victoria) Act 1995 (Vic), National Environment Protection Council (Queensland) Act 1994 (Qld), National Environment Protection Council (Western Australia) Act 1996 (WA), National Environment Protection Council (South Australia) Act 1995 (SA), National Environment Protection Council (Tasmania) Act 1995 (Tas), National Environment Protection Council Act 1994 (ACT) and the National Environment Protection Council (Northern Territory) Act 1994 (NT)"

The National Environment Protection Council (New South Wales) Act 1995 (NSW) records this in section 20 (1):

"The Council may vary or revoke any national environment protection measure."

It is therefore clear that the air quality targets in the approval conditions are backed by legislation.