Objectives and Standards for Particulate Matter


Canada-Wide Standards (CWS)

In June, 2000, federal and provincial ministers of the environment declared particulate matter and ozone to be toxic substances and established Canada-Wide Standards (CWS) for both of them as part of a long term goal of minimizing the health risks that these contaminants pose to human health and the environment. These standards represent a balance between achieving the best health and environmental protection possible and the feasibility and costs of reducing the pollutant emissions that contribute to PM and ground-level ozone in ambient air.

To view the full standard

Calculating the CWS PM 2.5 metric for a community is not simple. It requires at least three years of PM 2.5 data. The 30 ug/m3 standard is compared to the rolling average of the 98th percentile daily average value for each year. It is not a true daily standard that can be used for day to day air quality management.

In response to the need for a fine PM standard to address day to day air quality management, the Province adopted the new daily PM2.5 standard of 25 ug/m3 in 2009.


PM 2.5 - 25ug/m3 for a 24 hour averaging time
PM 2.5 - 8ug/m3 for an annual averaging time
PM 2.5 - 6ug/m3 for an annual averaging time planning goal
PM 10 - 50ug/m3 for a 24 hour averaging time.

Provincial PM2.5 Objective

Other Canadian and Provincial standards are found here.