Hexavalent chromium is a known carcinogen in humans and causes negative impacts to aquatic organisms. Regulations are now in force requiring facilities that use more than 50 kg of chromium trioxide per calendar year to reduce air emissions of hexavalent chromium, using one of three approved control methods. The regulations are intended to standardize permissible air emissions of hexavalent chromium, which is created by use of chromium trioxide, in the face of disparate provincial regulations.
The regulations allow users to choose between point source control, limiting surface tension, or use of a tank cover. Specific release limits are established, and inspection, maintenance and reporting obligations are imposed by the new regulations. Tests must be performed initially as prescribed by the regulations and then every 5 years thereafter. Tests must also be performed when specific modifications are made to the system such as replacement of a control device, increase in the surface area of the solution in the tank >25%, installation of additional tanks to increase total surface area >25% or a change to the ventilation system connected to the tank. Depending upon the control method chosen, users will have between 3 and 30 months to put the required measures into place.
Environment Canada estimates that the release of up to 31 tonnes of hexavalent chromium will be avoided as a result of the required control measures. The estimated monetary benefit is over $58 million, principally as a result of avoided health care costs. See Canada Gazette, June 24, 2009.