History

VOCs have long been recognized as a primary contributor to ground-level ozone formation. Ozone management programs in the United States in the 1970's focused mainly on volatile organic compounds (VOCs), largely ignoring NOx, the other primary pollutant involved in ozone formation. Today it is widely accepted that both VOCs and NOx must be controlled in order to reduce ambient concentrations of ground-level ozone. Many of the initiatives in the 1990 Phase I NOx/VOC Management Plan endorsed by the Canadian Council of Ministers of the Environment (CCME) in 1990 focused on reducing VOC emissions. More recently, the Ozone Annex to the Canada-U.S. Air Quality Agreement signed by Canada in 2000 contains commitments to reduce emissions of both VOCs and NOx.

In developing the Canada-wide Standards for PM and Ozone, which were endorsed by the CCME in 2000, VOCs were recognized as a precursor pollutant to both ground-level ozone and PM_2.5. Mass VOCs have now been included in Schedule 1: List of Toxic Substances of CEPA based on their contribution to PM_2.5 and ozone formation. In addition, a number of individual VOCs have been assessed to be CEPA toxic based on either their direct toxic effects and/or their contribution to ozone formation and are included in Schedule 1.