OCS offers you designated substance surveying for all types of buildings and projects. Please contact us to discuss your needs, get a free estimate, or schedule an appointment:
info@contaminantsolutions.com
613-884-9674
What are Designated Substances?
A designated substance is defined by the Occupational Health and Safety Act of Ontario (OHSA) as a biological, chemical, or physical agent or combination, which the exposure of a worker is:
- Prohibited;
- Regulated;
- Restricted; and
- Limited or controlled.
Employers are required to take reasonable precautions to protect workers, occupants, or others from known hazards. Substances that are specifically designated in Ontario include:
- Asbestos;
- Lead;
- Silica;
- Mercury;
- Arsenic;
- Benzene;
- Coke Oven Emissions;
- Ethylene Oxides;
- Isocyanates;
- Vinyl Chloride; and
- Acrylonitrile.
The most common designated substances encountered during construction operations are asbestos, lead, silica, and mercury.
Asbestos – Designated Substance
Asbestos is a group of naturally occurring mineral silicates. It has been used in a wide variety of construction materials due to its heat resistance, high tensile strength, and other properties. Asbestos has been used in the manufacture of thermal insulation, surfacing materials, and other miscellaneous building materials. The inhalation of asbestos has been associated with a number of respiratory diseases including cancer, asbestosis, and mesothelioma.
See our asbestos testing page for more info regarding asbestos.



Lead – Designated Substance
Lead is a chemical element that was used in a number of applications including the production of paint, pipes, and ammunition. Lead is an ingestion and inhalation hazard. It is a neurotoxin that can accumulate in the body and result in nervous system damage and other health effects.


Silica – Designated Substance
Silica is a common material found in rock, sand, and building materials such as asphalt, brick, and mortar. It has been used in a variety of construction material because of its hardness. Inhalation of silica can result in irreversible silicosis (lung disease).


Mercury – Designated Substance
Mercury is the only metal element that exists in the liquid state at standard pressure and temperature. It has been used in thermostats, switch gear, fluorescent light tubes/bulbs, and thermometers. Exposure to mercury is known to cause a wide variety of serious health affects in individuals.



The remaining designated substances are usually not discovered during designated substance surveying. They are sometimes discovered in industrial, laboratory, and agricultural buildings.
Mandatory Designated Substance Surveying
According to OHSA Designated substance assessment is mandatory in Ontario prior to:
- “Construction of a building, bridge, structure, industrial establishment, mining plant, shaft, tunnel, caisson, trench, excavation, highway, railway, street, runway, parking lot, cofferdam, conduit, sewer, watermain, service connection, telegraph, telephone or electrical cable, pipe line, duct or well, or any combination thereof”
- “Moving of a building or structure”
- “Any work or undertaking, or any lands or appurtenances used in connection with construction”
Before beginning a project, Project Owners must carry out the following in accordance with OHSA:
- Provide a list of all designated substances to potential contractors reasonably known to be present at project Site;
- Include the above info as part of all tenders; and
- Ensure any prospective contractor has received this list of designated substances before entering a binding contract.
Designated Substance Assessment Methodology
A qualified consultant carries out surveying using the following methodology:
- Conducting a visual inspection of building/material(s) of concern.
- Collection of representative samples of potential asbestos containing materials and lead paint (optional).
- Materials are analysed using a 3rd party accredited Laboratory.
- Preparation of a formal report detailing findings, regulatory requirements, and appropriate recommendations.
Please contact OCS to discuss your needs, get a free estimate, or schedule an appointment. OCS is based in Ottawa,Ontario, Canada. We service all surrounding areas including Kingston and Cornwall.
1-125 Pretoria Avenue
Ottawa, ON K1S 1W8
hello@contaminantsolutions.com
613-884-9674