Objectives and Standards
Air quality objectives are limits on the acceptable presence of contaminants in the atmosphere, established by government agencies to protect human health and the environment. They are generally expressed
in terms of a concentration (e.g., micrograms per cubic metre, or parts per billion) measured over a specific period of time (e.g., one hour, 24 hours or one year).
Objectives are one kind of "criteria." Criteria also include standards, guidelines and planning goals.
British Columbia has adopted air quality objectives and standards for a number of contaminants, including: PM10, PM2.5, ozone, sulphur
dioxide, nitrogen dioxide and carbon monoxide.
In April 2009, B.C. adopted new air quality objectives for PM2.5.
In 2011, the Ministry of Environment established a provincial framework to guide the development of air quality objectives. This framework outlines the key goals and guiding principles that are used to inform decisions related to the setting of provincial air quality objectives; the general approach to develop objectives; and opportunities for future stakeholder involvement.
In 2012, the Minister of Environment endorsed new Canadian Ambient Air Quality Standards (CAAQS) for PM2.5 and ground-level ozone, and began reporting on achievement of the CAAQS in 2015.
In October 2014, the Province adopted interim ambient air quality objectives for nitrogen dioxide (NO2) and sulphur dioxide (SO2). The interim SO2 objective was subsequently updated in December 2016. For updated guidance documents on the application of the interim NO2 and SO2 objectives, see: Guidance on Application of Provincial Air Quality Objectives for NO2 (PDF) and Guidance on Application of Provincial Air Quality Objectives for SO2 (PDF).
In October 2016, the Minister of Environment endorsed new CAAQS for SO2. An information sheet describing the new CAAQS is currently being updated.
For more information, see Provincial Framework for Developing Provincial Air Quality Objectives (PDF: 110 KB/2 pages).
How are air quality objectives used?
Air quality objectives are nonstatutory limits used to guide decisions, unless written specifically into a permit or regulation. They are typically used to:
- assess current or historical air quality;
- guide decisions on the permitting of new or modified facilities;
- guide decisions on episode management, such as air quality advisories;
- develop long-term air-management strategies and evaluate progress, and
- aid 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.