On February 1, 2010, changes to Ontario Regulation 419/05, Air Polution - Local Air Quality (O.Reg. 419/05), came into effect. These changes require industrial facilities to meet stricter air standards for 33 contaminants.

The changes include a reduction in lead and acetone by approximately 75 per cent, the creation of standards for acetonitrile and methyl isocyanate, and a reduction of xylenes by almost two-thirds. The Government of Ontario has indicated that the purpose of these changes is to "better protect air quality and health in local communities".

The news release of the Government of Ontario which provides an overview of these changes, and a list of the 33 contaminants, can be accessed here.