Standards and goals for measuring air pollution

Setting air quality standards and goals are essential for protecting human health and the environment from the adverse effects of air pollution.

High concentrations of the major air pollutants are associated with respiratory problems such as coughs, bronchitis, asthma and, in severe cases, developmental problems in children, and even death. 

The National Environment Protection Measure for Ambient Air (Air NEPM) sets national standards for the six key air pollutants to which most Australians are exposed: carbon monoxide, ozone, sulfur dioxide, nitrogen dioxide, lead and particles.

Standards refer to maximum concentrations of the pollutants set by Air NEPM. Goals refer to allowable exceedances of these maximum concentrations during a year. Find out what these goals and standards are in the table below.

Standards and goals

Pollutant

Averaging period

Maximum concentration or standard

Goal (maximum allowable exceedences)

Carbon monoxide

8 hours

9.0 ppm

1 day a year

Nitrogen dioxide

1 hour

1 year

0.12 ppm

0.03 ppm

1 day a year

none 

Ozone 

1 hour
4 hours

0.10 ppm
0.08 ppm

1 day a year

1 day a year

Sulfur dioxide

1 hour

1 day

1 year

0.20 ppm

0.08 ppm

0.02 ppm

1 day a year

1 day a year

None

PM10

1 day

1 year

50 µg/m3

25 µg/m3

None, excluding exceptional event days

None

 PM2.5

1 day

1 year

25 µg/m3

8 µg/m3

None, excluding exceptional event days

None

Visibility or NEPH (as bsp)

1 hour

3 x 10-4 m-1 (300 Mm-1)

See notes

Notes

 ppm
 = 
parts per million by volume (that is, parts of pollutant per million parts of air)
 PM10
=
particulate matter less than 10 micrometres in diameter
 PM2.5
= particulate matter less than 2.5 micrometres in diameter
 µg/m3
= micrograms per cubic metre, referenced to a temperature of 0° Celcius and an absolute pressure of 101.325 kilopascals.
 bsp
=

back scattering potential, which represents the coefficient of light scattering due to particles and is a measure of visibility reducing particles. The lower the bsp value, the lower the level of suspended particles and the better the visibility.

There is no AAQ NEPM standard or goal for visibility. The value of 210 Mm-1 (inverse megametres) was the NSW adopted 1 hour standard before November 2020, after which 300Mm-1 was adopted as the current NSW 1 hour standard for NEPH.

Exceptional event
=

defined under Clause 18 of the AAQ NEPM as a ‘fire or dust occurrence that adversely affects air quality at a particular location and causes an exceedance of 1-day average standards in excess of normal historical fluctuations and background levels, and is directly related to: bushfire; jurisdiction authorised hazard reduction burning; or continental scale windblown dust’.

When reporting compliance against NEPM goals for both PM10 and PM2.5 daily averages, any exceedance day deemed to be impact6ed by an exceptional event is excluded and classified as an exceptional event day. Where an exceedance day is determined to be impacted by a non-exceptional event, it is included  and classified as a non-exceptional event day.