Human Resources Policies
Indoor Air Quality (IAQ) Policy For Office Environments

Category: Health and Safety
Sub-Category: General

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Policy Statement


The City of Toronto is committed to achieving and maintaining acceptable indoor air quality (IAQ) in City-owned and leased buildings occupied by its employees, in accordance with legislative requirements and generally accepted industry standards.

Acceptable office IAQ, as defined by the American Society of Heating, Refrigeration and Air-Conditioning Engineers (ASHRAE), is air in which there are no known contaminants at harmful concentrations and with which a substantial majority (i.e. 80% or more) of the people exposed do not express dissatisfaction. Generally accepted industry standards include ASHRAE ventilation and thermal comfort standards.


This policy applies at all City-owned or leased buildings or parts of buildings regularly occupied by City staff in offices or other non-industrial work spaces (e.g. homes for the aged, child care facilities, hostels, shelters, living quarters in firehalls, community centres). It does not incorporate other requirements specific to these environments that may also apply [e.g. Ministry of Health standards governing heating, ventilation and air conditioning (HVAC) system design requirements for infection control purposes].

City facilities where there is an industrial process or use/generation of chemicals (e.g. water filtration/treatment facilities, transfer stations, pools, arenas, print shops) are addressed in the Industrial Air Quality Policy.

All City divisions, supervisors and contractors engaged in IAQ management services at buildings occupied by City staff, as well as City occupants of these buildings, will implement the provisions of this policy.

It is not within this policy to address the concerns of individuals who report adverse health effects and/or symptoms of discomfort even when generally accepted industry standards are met. Concerns of individuals with medically documented conditions must be addressed on a case by case basis through the City’s employment accommodation process. Guidelines to assist such accommodations are developed, as required.


The City’s senior management team will ensure that:

  • Responsibility for IAQ management in each City building is clearly defined.
  • Acceptable indoor air quality is achieved and maintained in buildings occupied by City staff.

Senior management of the division with responsibilities for maintenance of acceptable IAQ (Facilities Management) will ensure that the steps outlined below are implemented:

  • When leasing third party office space or relocating to a City-owned facility, request information on HVAC system capabilities (as outlined in Appendix A) and ensure that this information is provided to management of the City division that is considering occupying the space so that an informed leasing decision can be made by the client division.
  • When leasing third party office space, make every reasonable effort to ensure that a clause requiring compliance with current ASHRAE standards (i.e. current at the time the lease is signed) is incorporated into leasing agreements with building owners. Advise management of occupants whether this clause has been successfully included in the leasing agreement.
  • Upon receipt of information from divisions identifying non-compliance with the indoor air quality provisions of the leasing agreement, contact the landlord and, if necessary, Legal Division to have the concern addressed.
  • With respect to existing leased buildings where IAQ monitoring in response to occupant concerns indicates non-compliance with current IAQ guidelines (see Appendix B), ensure that deficiencies with significant cost implications are raised for discussion regarding corrective action with the building owner at the time of re-negotiation of the current lease.
  • With respect to existing City-owned buildings where IAQ monitoring in response to occupant concerns indicates non-compliance with current IAQ guidelines, ensure:

    • Documentation of identified deficiencies is maintained (e.g. notes re employee concerns, IAQ assessment reports).
    • The need for corrective action is prioritised based on degree of deviation from current standards, duration of exposure, frequency of exposure, number of staff impacted, past history of concerns and occupancy tenure and/or as part of building renovations.
    • Plan and budget for corrective action on identified priorities.
  • If own staff will provide IAQ management services, ensure training is provided so that they can effectively discharge their responsibilities.
  • If in-house expertise is not available, establish a service level agreement with internal or external service provider to provide ongoing IAQ management services, including a preventative maintenance plan for the building HVAC system. The preventative maintenance plan should include inspections of building HVAC system components at the frequency outlined in the City's Facilities Maintenance Standards. Activities as outlined in the plan are to be completed by competent persons (i.e. persons qualified by training and experience in HVAC system operation and maintenance).
  • Maintain documentation of HVAC system capabilities, limitations and maintenance activities on-site and provide to parties involved in addressing indoor air quality concerns so that the Indoor Air Quality Testing Requests (Appendix C) can be appropriately completed when occupants raise IAQ issues.
  • Respond in a timely manner to occupant IAQ concerns by ensuring an investigation into HVAC system efficiency is carried out and advising party making request of the outcome.
  • Assist occupational health and safety staff in IAQ investigations, as required.
  • Review repair orders generated as a response to recommendations of joint health and safety committees (JHSCs), occupants, health and safety staff and/or those employees who conduct periodic routine inspections, and address or promptly communicate same to building owner or service provider, to address.
  • Ensure that the provisions of Guidelines for Addressing the Health and Safety Aspects of Renovations are applied during renovations or when introducing new materials into a new or existing space. Ensure that air balancing is carried out, as needed, after changes have been made to office layout.
  • Advise senior management of other divisions that occupy building of any scheduled or emergency renovation or repair work that could negatively impact occupant air quality

Senior Management of all divisions that occupy buildings will ensure that the steps outlined below are implemented:

  • When considering relocating to a City-owned or leased building or when acquiring a building, advise City division with responsibilities for maintenance of acceptable IAQ or landlord, as appropriate, of operational issues that may impact indoor air quality, including anticipated number of occupants and the types and locations of equipment to be installed.
  • In the case of acquiring a building with identified HVAC system deficiencies (as identified in information provided by the landlord), develop a plan for addressing identified deficiencies within a reasonable period of time, and, preferably prior to occupancy. Ensure that this plan is identified in report prepared for Council/CAO as appropriate.
  • When relocating to a City-owned building where the HVAC system will not meet identified needs and a decision is made to nevertheless proceed with the move, develop a plan with City division with responsibilities for indoor air quality management for addressing deficiencies within a reasonable time period, and, preferably, prior to occupancy.
  • After occupancy, when it is necessary to add extra persons, equipment or products to the space, consult with City division with responsibilities for maintenance of acceptable IAQ, building owner, own qualified staff or external service provider, as appropriate to confirm whether IAQ guidelines will be maintained after addition. If IAQ will be adversely impacted, identify who is responsible for upgrades and follow-up to ensure necessary changes made to HVAC system to compensate for space changes made.
  • Ensure that IAQ concerns are promptly investigated, City division with responsibilities for maintenance of acceptable IAQ, building owner, own qualified staff or external service provider are notified of the nature of concerns, requesting corrective action, if required.
  • Ensure that a logging system (i.e. record of employee IAQ complaints and any follow-up action taken) is maintained.
  • Where concerns remain unresolved, background information as outlined in the IAQ Testing Request is collected and provided to occupational health and safety staff to facilitate IAQ investigation.
  • Employees and the joint health and safety committee/representative are advised of any scheduled or emergency renovation or repair work that could negatively impact occupant air quality.
  • A copy of any indoor air quality monitoring reports is provided to the joint health and safety committee/representative and workers are notified of results.
  • Consult with City division with responsibilities for maintenance of acceptable IAQ, building owner, own qualified staff or external service provider on appropriate means of addressing identified IAQ deficiencies and the procedures for addressing the same.

Occupational Health, Safety and Workers’ Compensation Unit’s occupational hygiene staff will:

  • Upon request of Facilities Management staff or occupant divisions, review information on HVAC system capabilities of building being considered for occupancy under proposed occupancy conditions to determine whether it is capable of providing acceptable air quality.
  • Lead in the development of procedures, guidelines and training programs to facilitate compliance with this policy.
  • Assist in addressing employee IAQ-related concerns.
  • Upon receipt of background information on concerns collected on the IAQ Testing Request, initiate IAQ testing as appropriate, report to appropriate parties (i.e. building management, service area management, joint health and safety committees) and make recommendations for corrective action, as appropriate based on test results.
  • Provide IAQ test information identifying non-compliance with indoor air quality provisions of the leasing agreement to party responsible for the lease, for use when contacting the landlord for follow-up.

Health and safety staff will:

  • Provide consultation to members of the JHSC as they prepare and recommend appropriate remedial actions or seek an occupational hygiene assessment.
  • Consult regarding the provision of training and development of safe work procedures.
  • Assist management or JHSC’s of divisions that occupy buildings in collecting background information on occupant concerns as outlined in the IAQ referral form.

Joint Health and Safety Committees representing building employees:

  • Include evidence of any indications of potential IAQ problems (e.g. water stains, musty odours, indoor air quality complaints) as part of their routine workplace inspections.
  • Bring deficiencies, if any, to the attention of area supervisors with a copy of the notice forwarded to occupational health and safety staff.

Workers will:

  • Advise their supervisors of any IAQ-related occupational health and safety issues or concerns.
  • Not take any actions that adversely impacts HVAC system performance (e.g. blocking air intakes) or circumvents HVAC system normal operation (e.g. opening windows or doors will adversely impact operation of the mechanical system).

The Occupational Health and Safety Co-ordinating Committee will:

  • Monitor the implementation and effectiveness of this policy

Appendix A

Heating, ventilating and air-conditioning (HVAC) system capabilities information to be requested prior to leasing third party office space or prior to relocating to a City-owned facility:

  • What is total HVAC system capability in cubic feet per minute (cfm) or litres per second (L/sec) for space being considered for occupancy?
  • What is HVAC system capability in cubic feet per minute (cfm) per floor or litres per second (L/sec) if more than one floor is to be occupied?
  • What is area in square feet (ft2) or square meters (m2) of space being considered for occupancy?
  • What is ceiling height in feet (ft) or meters (m) of space being considered for occupancy?
  • Is HVAC system capable of providing the following temperature ranges?

    • in winter: 20.5-25.5 ºC (if 30% relative humidity) or 20-24 ºC (if 60% relative humidity)
    • in summer: 24.5-28 ºC (if 30% relative humidity or 23-25.5 ºC (if 60% relative humidity)
  • Does HVAC system have central humidification capabilities?

Appendix B


Table outlines general indoor air quality parameters and recommended ranges as well as jurisdiction from which recommendation is derived

General Indoor air quality parameter Recommended guideline Jurisdiction
Carbon dioxide <1000 ppm or <700 ppm above outdoor carbon dioxide concentration ASHRAE, MOL

If 30% Relative Humidity

24.5-28°C (summer)

20.5-25.5°C (winter)

If 60% Relative Humidity

23-25.5°C (summer)

20-24°C (winter)

% Relative Humidity <60 ASHRAE

*Adopted from the Canadian Centre for Occupational Health and Safety (CCOHS) website

Specific Indoor air quality parameter Recommended guideline Jurisdiction
Carbon monoxide <9 ppm ASHRAE
Formaldehyde <0.1 ppm Health Canada

1 mg/m3 (target level)

5 mg/m3 (action level)

Health Canada
Particulates (**PM10) 150 µg/m3 (averaged over 24 hours) ASHRAE

**PM10 refers to particulate matter less than 10 microns

Appendix C


  • The Occupational Health and Safety Act (R.S.O. 1990)
  • City of Toronto Corporate Occupational Health and Safety Policy (1999)

Endorsed by

  • Occupational Health and Safety Coordinating Committee (OHSCC), August 10, 2004
  • Reviewed & Revised by OHSCC: February 28, 2016 & April 26, 2016

Approved by

City Manager, October 12, 2004

Date Approved

October 12, 2004

Reviewed & Revised by OHSCC

April 26, 2016

Related Information

  • ASHRAE Standard Ventilation for Acceptable Indoor Air Quality 62.1-2010 or most recent version *
  • ASHRAE Thermal Environmental Conditions for Human Occupancy 55-2010 or most recent version *
  • Health Canada Indoor Air Quality in Office Buildings: A Technical Guide 93-EHD-11 (Revised 1995) *
  • City of Toronto Renovation Projects Guideline **
  • City of Toronto Scented Product Guidelines**
  • City of Toronto Facilities Maintenance Standards***


Appendix C.doc (43 Kbytes)
Appendix C.pdf (22 Kbytes)
Appendix C_processed FINAL-s.pdf (127 Kbytes)

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