Air quality objectives and standards
Last updated on January 20, 2026Air quality objectives are non-statutory limits on the acceptable presence of contaminants in the atmosphere. These objectives are established by government agencies to protect:
- Human health
- The environment
They are generally expressed with a combination of:
- A concentration. For example, micrograms per cubic metre, or parts per billion
- A measurement of time. For example, one hour, 24 hours or one year
British Columbia has adopted air quality objectives and standards for a number of contaminants, including Particulate Matter (PM10 and PM2.5), ozone, sulphur dioxide, nitrogen dioxide and carbon monoxide.
Objectives are one kind of criteria. Criteria also include:
- Standards
- Guidelines
- Planning goals
How air quality objectives are used
Air quality objectives are used to guide decisions unless they are written specifically into a permit or regulation at which point they become binding requirements. They are typically used to:
- Assess current or historical air quality
- Guide decisions on the permitting of new or modified facilities
- Guide decisions to issue air quality warnings
- Develop long-term air-management strategies and evaluate progress
- Aid in regulatory development
As even low levels of air pollution can affect some individuals, air quality objectives should not be viewed as levels we can 'pollute up to', but levels to stay well below.
Objectives and standards
| Air contaminant | Metric or criteria | Air quality objective | Calculation method |
|---|---|---|---|
| Fine Particulate Matter (PM2.5) | 24-hour | 25 µg/m3 | 98th percentile of daily average over one year |
| Annual | 8 µg/m3 | Annual average of daily values over one year | |
| Particulate Matter <10 microns (PM10) | 24-hour | 50 µg/m3 | Average over 24-hour averaging period |
| Ozone (O3) | 8-hour | 60 ppb | Annual 4th highest daily 8-hour maximum over three years |
| Nitrogen Dioxide (NO2) | 1-hour | 60 ppb | Annual 98th percentile of daily 1-hour maximum over three years |
| Annual | 17 ppb | Annual average of 1-hour values over one year | |
| Sulphur Dioxide (SO2) | 1-hour | 65 ppb | Annual 99th percentile of daily 1-hour maximum over three years |
| Annual | 4 ppb | Annual average of 1-hour values over one year |
Implementation Guidance
For more information, read the Provincial Framework for Developing Provincial Air Quality Objectives (PDF, 192.2KB).