The National Environmental Standards for Air Quality (NES-AQ) are set by the New Zealand Government and are legally binding in New Zealand. The NES-AQ set limits for five air pollutants and allow some exceedances. Air quality indicators compared to the NES-AQ include daily average PM10, hourly average nitrogen dioxide and sulphur dioxide. A national standard for PM2.5 is pending.
Regional councils and unitary authorities are responsible for managing air quality under the Resource Management Act. They are required to identify areas where air quality is likely, or known, to exceed the NES-AQ. These areas are known as airsheds.