The City of Toronto is committed to achieving and maintaining acceptable air quality in all workplaces that are occupied by City employees, in accordance with legislative requirements and generally-accepted industry standards. From the perspective of exposure to chemical and biological substances, the City is committed to ensuring that employees are not exposed to these substances at concentrations that may cause adverse health effects.
This policy applies at all work locations in which City employees engage in industrial-type work. All City divisions and staff will implement the provisions of this policy, as appropriate to the work operations performed and chemical and biological substances used or generated.
This policy does not apply to work locations or those areas of work locations that are addressed by the Indoor Air Quality Policy.
Work in which chemical or biological substances are used or generated as a result of work operations. This includes work performed within shops (e.g. wood-working shops, welding shops, vehicle maintenance shops, laboratories, plants, garages), underground or outdoors, if the nature of work performed may result in employee exposure to substances regulated under the Regulation respecting Control of Exposure to Biological or Chemical Agents or Designated Substances Regulation, made under the Occupational Health and Safety Act.
A person who is qualified, by training and experience, to perform the work.
Occupational exposure limits (including TWAs, STELs and Cs)
The time-weighted average limit (TWA) is the average of the airborne concentrations of a biological or chemical agent determined from air samples of the airborne concentrations to which a worker is exposed in a work day or a work week. If the Regulation respecting Control of Exposure to Biological or Chemical Agents or Designated Substance Regulation sets out a time-weighted average limit (TWA) for the agent, exposure shall not exceed that value.
The short-term exposure limit (STEL) is the maximum airborne concentration of a biological or chemical agent to which a worker is exposed in any fifteen-minute period determined from a single sample or a time-weighted average of sequential samples taken during such period
The ceiling limit (C) is the maximum airborne concentration of a biological or chemical agent to which a worker is exposed at any time.
Engineering controls (e.g. local ventilation), work practice controls, administrative controls, hygiene facilities and personal protective equipment (where appropriate)
This policy supplements the City’s Workplace Hazardous Materials Information System policy.
Chemical and biological hazards are assessed to determine whether employees, under routine, non-routine or emergency conditions, may be exposed to concentrations of chemical or biological substances that approach or exceed occupational exposure limits (OELs) and consequently may result in short- or long-term adverse health effects. Occupational health and safety staff, as needed, as well as joint health and safety committees or health and safety representatives will be consulted when assessing hazards.
Occupational hygiene assessments, where appropriate or needed, will be conducted to evaluate whether employee exposures to chemical or biological substance(s) may place their health at risk.
Occupational hygiene assessments are needed if:
When concentrations of chemical or biological substances in City work locations are determined, through occupational hygiene monitoring, to exceed 50% of the appropriate OEL (TWA, STEL or C), recommendations to lower employee exposure will be made and implemented, wherever practicable.
Preventive measures/controls to ensure that employee exposure to chemical and biological substances is below established OELs will be introduced.
If introduction of a control requires completion of a pre-start health and safety review (see Appendix A), the review will be conducted and documented in accordance with legislated requirements.
Engineering controls (e.g. local exhaust system or general ventilation system) will be maintained according to manufacturer’s instructions or accepted industry standards [e.g. Canadian Standards Association (CSA), American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), American National Standards Institute (ANSI)]. Regular inspections of these controls will be conducted by qualified persons. Questions with respect to these controls (e.g. Are the controls working? Are they being maintained?) should be included in the workplace inspection checklist of the joint health and safety committee or health and safety representative representing workers who are impacted by these controls.
When selecting controls, engineering and administrative controls will be given priority over the provision and use of personal protective equipment. Personal protective equipment may be provided and used when engineering or other controls:
If personal protective equipment is required or requested by an employee to minimize employee exposure to chemical or biological substances, employees will be trained in its use, storage, maintenance, fit and limitations. Fit testing is required whenever the employer provides a respirator to an employee, to be used on either a mandatory or voluntary basis.
When renovations or changes in work operations may result in change of facility usage (in whole or in part) from non-industrial to industrial-type usage, the Division whose work requires the use of chemical or biological substances or results in the generation of a chemical or biological substance(s) will ensure that the space is properly equipped to prevent overexposure of those employees within and adjacent to the space.
When work operations are changed such that increased amounts of chemical or biological substances are used or generated, hazards are re-assessed and preventive measures/controls are amended, as needed.
When work operations require the use of chemical substances, efforts will be made to purchase and use the least hazardous substance operationally feasible. Prior to use of any new chemical, a hazard assessment will be undertaken.
When equipment is being purchased or replaced, efforts will be made to ensure that such equipment minimizes the potential for employee exposure to chemical or biological agents.
Where continuous monitoring devices are installed to protect employees from overexposure to chemical substances, these devices should be appropriate to the chemical substance(s) of concern and any alarm set points for these devices should be set at concentrations that will prevent employees from being overexposed. Auditory and/or visual alarms, as appropriate to work operations, should be used. Calibration should be conducted at the frequency recommended by the manufacturer or accepted industry standards.
Changes to OELs will be monitored on an ongoing basis and communicated to City representatives (management, joint health and safety committees or health and safety representatives, Occupational Health and Safety Co-ordinating Committee).
The Occupational Health and Safety Act (R.S.O. 1990)
Designated Substances Regulation (O.Reg 490/09)
Regulations for Industrial Establishments (O.Reg 851), Sections 7 and 8, Pre-start Health and Safety Reviews
Regulation Respecting Control of Exposure to Biological and Chemical Agents (O.Reg. 833)
Workplace Hazardous Materials Information System (WHMIS) Regulation (Regulation 860)
Corporate Occupational Health and Safety Policy
In the context of a City occupational health and safety policy regarding air quality in industrial type settings, a pre-start health and safety review may be required under the Regulations for Industrial Establishments in determining the adequacy of ventilation systems. Such a review may also be beneficial for work operations that are addressed by other sector regulations. A review will be necessary if a new apparatus, structure or protective element is to be constructed, added or installed or an existing apparatus, structure or protective element is to be modified in a process that uses or produces a substance that may result in the exposure of a worker in excess of occupational exposure limits. These limits are set out in the Designated Substances Regulation and the Regulation respecting Control of Exposure to Biological or Chemical Agents.
The Regulations for Industrial Establishments (Section 7) requires that “knowledgeable” persons conduct pre-start health and safety reviews. The Ministry of Labour has identified that pre-start health and safety reviews to confirm the adequacy of ventilation systems, so as to ensure the atmosphere will not endanger the health and safety of workers, should be conducted by persons who, in the opinion of the employer or owner, possesses special expert or professional knowledge or qualifications appropriate to assess the potential or actual hazard. The Ministry of Labour will recognize professional engineers and/or persons with credentials such as Certified Industrial Hygienist (CIH) or Registered Occupational Hygienist (ROH) as knowledgeable persons for the purpose of this type of pre-start health and safety review.
Reports of pre-start health and safety reviews must be signed by the reviewer(s) and dated. The reports of pre-start health and safety reviews must be provided to joint health and safety committees or health and safety representatives before the new or newly-modified apparatus, structure or protective element is operated or the process is used. These reports must also be kept readily accessible in the workplace together with any supporting documentation.
Occupational Hygiene Testing Request form
Occupational Health & Safety Co-ordinating Committee (OHSCC), September 19, 2006
February 28, 2012
April 26, 2016
February 8, 2017
City Manager, January 24, 2007
January 24, 2007
February 8, 2017
Workplace Hazardous Materials Information System (WHMIS) Policy
City of Toronto Renovation Projects Guideline
Policy for Incorporating Occupational Health, Safety and Ergonomics Principles into the Purchasing Process