Eleven substances have been “designated” in Ontario - acrylonitrile, arsenic, asbestos, benzene, coke oven emissions, ethylene oxide, isocyanates, lead, mercury, silica and vinyl chloride.

Only four of these eleven substances are commonly encountered and include:

• asbestos in building materials;
• lead in paint applications and in solder used in joints of copper pipe;
• mercury in thermometers, pressure gauges, electrical switches and relays, and as a preservative in some paints; and
• silica in concrete, masonry, stone and boiler refractory.

The Ontario Occupational Health and Safety Act requires that a list of all designated substances at a project site be provided to all bidders at the tendering stage.  A Designated Substance Survey (DSS) identifies the designated substances present, their locations and concentrations.  This information allows contractors involved in demolition or renovation activities to take appropriate steps to control exposure of workers and the general public to the designated substances that are present.

Lead, being a common component in paint, particularly in older buildings where lead concentrations may be very high, can be a significant issue, especially in residential or institutional facilities.  Paints, enamels and other liquid coating materials for use on the interior and exterior surfaces of buildings are classified as “restricted products” under the Federal Hazardous Products Act if they contain more than 0.5 percent weight-to-weight (5,000 ppm) of lead.

The Ontario Ministry of Labour has recently released a draft guideline for control of exposure to Lead on construction projects.  The guideline provides procedures designed to minimize exposure of workers to lead during construction, renovation or demolition activities.  The Ministry of Labour has also published a draft guideline for control of exposure to Silica on construction projects.  The procedures defined in the guideline are similar to those in the Lead guideline.

DCS can provide a complete range of services for the assessment and remediation of designated substances including:

• preliminary site inspection to establish the likely presence of designated substances;
• collection of representative samples for laboratory analysis;
• estimation of quantities of any substances present;
• provision of recommendations to address the presence of the designated substances during building renovations or demolition;
• preparation of contract specifications for removal and disposal of the substances; and
• supervision of remediation contractors.

Contact DCS for more information on Designated Substance Surveys.

Back | Home