B.C. Air Quality

New Ambient Air Quality Criteria for PM2.5

New ambient air quality criteria for PM2.5 were adopted by the Province of B.C. on April 9, 2009. They are nonstatutory limits used to guide air-management decisions in British Columbia. For information on the process by which the criteria were developed, view New Ambient Air Quality Criteria for PM2.5: Development Process.

PM2.5, or fine particulates, refers to particles that are 2.5 microns or smaller in diameter. PM2.5 is one of the most important outdoor air pollutants in B.C. from a human health perspective.

New Provincial Ambient Air Quality Criteria for PM2.5



Averaging Period

Air Quality Objective

25 µg/m3

24 hours1

Air Quality Objective

8 µg/m3


Planning Goal

6 µg/m3


1. Achievement based on annual 98th percentile value.

See also Air Quality Objectives and Standards for British Columbia and Canada (PDF: 13 KB/1 page).

The 24-hour and annual air-quality objectives (AQOs) are the primary air management tool, used to guide decisions on environmental impact assessments and authorizations, airshed planning efforts and regulatory development. The 24-hour AQO is also used to guide decisions on whether or not to issue an air quality advisory.

The planning goal is intended as a voluntary target to guide airshed planning efforts and encourage communities to maintain good air quality in the face of economic growth and development.

The new provincial criteria for PM2.5 are in addition to the existing provincial AQO of 50 µg/m3 (24-hour average) for PM10 (i.e., fine particles 10 micrometres or smaller). See Air Quality Objective for PM10.


To guide implementation of these criteria, the Ministry of Healthy Living and Sport has released Guidance on Application of Provincial Air Quality Criteria for PM2.5 (PDF: 182 KB/18 pages). Prepared in co-operation with the Ministry of Environment, this guide provides an overview of how air quality criteria are considered in regional decision making. It also includes specifics related to applying the new PM2.5 criteria to decisions on authorizations, air quality advisories and airshed planning.

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