Designated Substance Surveying

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:



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:

  1. Prohibited;
  2. Regulated;
  3. Restricted; and
  4. 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:

  1. Asbestos;
  2. Lead;
  3. Silica;
  4. Mercury;
  5. Arsenic;
  6. Benzene;
  7. Coke Oven Emissions;
  8. Ethylene Oxides;
  9. Isocyanates;
  10. Vinyl Chloride; and
  11. 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.

Testing for Asbestos - CT
Suspended Ceiling Tiles, Asbestos Containing
Vermiculite Testing for Asbestos
Vermiculite Asbestos Containing Insulation. High Risk Material.
Testing for Asbestos - Pipe Fittings
Pipe Fitting Parging Insulation, Located on Valves, Elbows, T-Junctions, Hangers, etc., Concealed beneath Jacketing

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.


Lead-Based Paint, Designated Substance Surveying
Lead-Based Paint
Lead Containing Bell Fitting Packing, Designated Substance Surveying
Lead Containing Bell Fitting Packing, Designated Substance Surveying


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).

Silica Containing Block & Floor, Designated Substance Surveying
Silica Containing Concrete Block and poured Concrete Floor
Ceramic Tile, Designated Substance Surveying
Silica Containing Ceramic Tile


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.


Mercury Thermometers, Designated Substance Surveying
Mercury Containing Thermometers
Mercury Containing Thermostat, Designated Substance Surveying
Mercury Containing Thermostat
Mercury Containing Fluorescent Lights, Designated Substances Surveying
Mercury Containing Fluorescent Lights













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:

  1. “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”
  2. “Moving of a building or structure”
  3. “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:

  1. Provide a list of all designated substances to potential contractors reasonably known to be present at project Site;
  2. Include the above info as part of all tenders; and
  3. 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:

  1. Conducting a visual inspection of building/material(s) of concern.
  2. Collection of representative samples of potential asbestos containing materials and lead paint (optional).
  3. Materials are analysed using a 3rd party accredited Laboratory.
  4. 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.


Contact Us

Ottawa Contaminant Solutions 

1-125 Pretoria Avenue
Ottawa, ON  K1S 1W8