CAAQS are the driver for air quality management across the country under the Air Quality Management System (AQMS). Standards have been developed for fine particulate matter (PM2.5 ) and ozone, and work has begun to develop standards for nitrogen dioxide (NO2) and sulphur dioxide (SO2). The CAAQS for PM2.5 and ozone were established as objectives under the Canadian Environmental Protection Act 1999, in May 2013 and replace the Canada-wide Standards for Particulate Matter and Ozone. The 2020 standards for PM2.5 and ozone will be reviewed in 2016. CCME resources on PM2.5 and ozone can be found here.