Ventilation

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Air quality is influenced by a many factors, including location of the work, climate, and presence of air contaminants. In a workplace, ventilation is used to control exposure to airborne contaminants. Ventilation systems impact air quality by introducing large quantities of air (by dilution ventilation) into the working area, or by pulling the air out of the work area at the source of where the contaminants are generated (by local exhaust). Ventilation can be accomplished by natural means (e.g., opening a window) or mechanical means (e.g., fans or blowers) depending on the situation.

Note: This topic does not apply to:

  • Underground mines
  • Confined spaces
  • A firefighter engaged in structural firefighting

Employer duties

Employers must make sure their workplace is properly ventilated so that the health and safety of workers is not at risk from poor air quality. This requirement can be achieved with natural ventilation or by using mechanical equipment to filter and move the air. [OHS General Regs., S. 11.1]

  • Natural ventilation involves using windows, shutters, or louvres which can be opened to allow the flow of air from outside. These features must have a combined area equal to at least five per cent of the floor area. [OHS General Regs., S. 11.7(a)]
  • If using mechanical ventilation, make sure the amount of outside air entering any room in the work room is at least 0.45 m3/min. (15 c.f.m.) per person. [OHS General Regs., S. 11.7(b)]

Employers must:

  • make sure contaminants are controlled at the source by installing mechanical ventilation systems that use hoods, ducts or other appropriate equipment; [OHS General Regs., S. 11.2]
  • make sure hazardous vapours, fumes, gases, mists or other contaminates in the air of working areas does not exceed the Threshold Limit Values (TLVs) as developed by the American Conference of Governmental Industrial Hygienists (ACGIH); [OHS General Regs., S. 11.3]
  • maintain and clean ventilation systems, including all its parts, to keep them in good repair, and keep any ventilation openings free form obstructions or sources of contamination; [OHS General Regs., S. 11.4]
  • make sure your workplace has at least 8.5 m3 (300 ft.3) of air space for each worker; [OHS General Regs., S. 11.6]
  • use a mechanical means of engineering design, which may include a ventilation system to prevent or eliminate workers from being exposed to hazardous contaminates in the air. Employers must make sure employees wear an approved respirator if exposure to hazardous contaminates in the air cannot be prevented or eliminated due to temporary conditions or an emergency; [OHS General Regs., S. 45.17]
  • make sure that the exhaust from the ventilation system is designed so that the contaminants do not re-enter the atmosphere of the work area; [OHS General Regs., S. 11.8]
  • make sure the relative humidity in an office environment is at least 30%; and [OHS General Regs., S. 11.9]
  • make sure the temperature of the workplace meets the minimum requirements set out below unless these exceptions apply. [OHS General Regs., S. 11.10]
Type of Work Mininum Required Temperature
Light work performed while sitting or any mental work, precision work, including reading or writing 20°C
Light physical work performed while sitting such as electric machine sewing and work with small machine tools 19°C
Light work performed while standing such as machine tool work 17°C
Moderate work performed while standing such as assembly and trimming 16°C
Heavy work performed while standing such as  drilling and manual work with heavy tools 12°C

Other ventilation requirements

Employers must also

Asbestos

An asbestos contractor must make sure that:

  • each enclosure is equipped with a ventilation system that is able to keep the enclosure under appropriate negative pressure which prevents the release of respirable asbestos fibres into the air outside of the enclosure; [OHS General Regs., S. 49.20 (1)]
  • when exhaust ventilation is used, the equipment is: [OHS General Regs., S 49.20 (2)]
    • designed and only used for asbestos abatement;
    • equipped with a HEPA filter;
    • maintained in good condition;
    • inspected regularly, according to the manufacturer; and
    • certified by a competent person at least once a year.
  • The capacity of the ventilation system has a minimum air exchange rate of at least 4 air changes per hour, and a differential pressure of at least 5 Pascals (-0.02 inches) of water. [OHS General Regs., S 49.20 (3)]

Workers

Workers must:

  • Follow the instructions, education and training about air quality provided by your employer, and properly use any equipment that is required.
  • Wear the respiratory protective equipment provided by the employer.
  • Be aware of changing conditions and air quality.
  • Report any hazards.
  • Do not enter a restricted area without authorization and appropriate personal protective equipment, as required by the employer.
TLVs are published in the Threshold Limit Values and Biological Exposure Indices for 2019, and as amended from time to time.
When calculating air space in a working area, exclude any space above 3.1 m (10 ft.). [OHS General Regs., S. 11.6]
Exceptions include if
·The work area is normally unheated,
·Opening doors makes it impractical to heat the area to the minimum requirement.
·Perishable foods and other goods that require lower temperatures are being processed or stored,
·Radiant heating allows employees in the working area to be as comfortable as they would be if the area was at the minimum requirement temperature, or
Keeping the area at the minimum requirement temperature would cause employees discomfort because of the effect of a work process or activity. [OHS General Regs., S. 11.11]

General Regulations
EC180/87

Part 2 TOILET AND WASHING FACILITIES

Section 2.2 Toilet facilities

2.2 Every employer shall at each workplace provide proper toilet facilities which shall be maintained and kept clean and shall have adequate provision for privacy, heat, light and ventilation.

Part 4 LUNCH ROOMS OR EATING AREAS

Section 4.1 Lunch and rest room

4.1 In every workplace the employer shall provide a clean lunch and rest room that

(a) does not have a door opening directly into a toilet facility;

(b) is separate from any place where there is the possibility of food being contaminated by a dangerous substance;

(c) is not used for any purpose that is incompatible with its use as a lunch room;

(d) is adequately provided with

(i) light, heat and ventilation,

(ii) hand cleansing and drying facilities in close proximity,

(iii) sufficient tables and seating facilities for the use of workers,

(iv) suitable covered receptacles for the disposal of food; and

(e) is kept in a sanitary condition.

[EC2021-126, s. 3]

Part 11 VENTILATION

Section 11.1 Adequate ventilation

11.1 The employer shall ensure that the workplace is adequately ventilated by either natural or mechanical means such that the atmosphere does not endanger the health and safety of workers under normal working conditions.

[EC2021-126, s. 3]

Section 11.2 Control systems

11.2 Where practical, contaminants shall be controlled at the source by means of hoods, ducts or such other means as may be necessary.

Section 11.3 Threshold limit values

11.3 Where the air of working areas is contaminated by vapours, fumes, gases, mists or other impurities which constitute a hazard to the health or safety of workers, suitable means of ventilation shall be provided by the employer to reduce contamination in the atmosphere at or below the threshold limit values specified by the American Conference of Governmental Industrial Hygienists (ACGIH) in the 2019 edition of the publication "Threshold Limit Values and Biological Exposure Indices", as amended from time to time.

[EC2020-147, s. 5; EC2021-126, s. 3]

Section 11.4 Maintenance

11.4 The employer shall ensure that all parts of ventilation systems are maintained, cleaned and that ventilation openings are always free of any obstruction or source of contamination.

Section 11.6 Air space requirement

11.6 The employer shall ensure that every workplace contains at least 8.5 m3 (300 ft.3) of air space for each worker. (When calculating the cubic meter (foot) requirement, height above 3.1 m (10 ft.) is excluded.)

[EC2021-126, s. 3]

Section 11.7 Means of ventilation

11.7 The employer shall ensure that every workplace shall be adequately ventilated by either

(a) natural ventilation provided by windows, shutters or louvres which can be opened, having a combined area equal to at least five per cent of the floor area; or

(b) mechanical ventilation, where the minimum amount of outside air introduced into any room is at least 0.45 m3/min. (15 c.f.m.) per person.

Section 11.8 Discharge

11.8 The employer shall ensure that the discharge of air from any exhaust system is in such a manner so as to prevent the return of contaminants to any workplace.

Section 11.9 Humidity

11.9 The employer shall ensure that the relative humidity in an office environment shall be a minimum of 30%.

Section 11.10 Temperature

11.10 The employer shall ensure that, subject to section 11.11, the temperature of an enclosed workplace corresponds with the following chart:

Table

NATURE OF WORK PERFORMED MINIMUM TEMPERATURE REQUIRED
Light work performed while sitting: any mental work, precision work, reading or writing 20°C
Light physical work performed while sitting: electric machine sewing and work with small machine tools 19°C
Light work performed while standing: machine tool work 17°C
Moderate work performed while standing: assembly and trimming 16°C
Heavy work performed while standing: drilling and manual work with heavy tools 12°C

Section 11.11 Exceptions

11.11 The minimum temperature required by section 11.10 does not apply at a workplace

(a) that is normally unheated;

(b) where the necessity of opening doors makes the heating of the area to the temperature specified in section 11.10 impractical;

(c) where perishable goods requiring lower temperatures are processed or stored;

(d) where radiant heating is such that a worker working in the area has the degree of comfort that would result were the area heated to the same temperature specified in section 11.10;

(e) where the process or activity is such that the temperature specified in section 11.10 could cause discomfort.

[EC2021-126, s. 3]

Part 26 EXPLOSIVES

Section 26.24 Ventilation, etc.

26.24 The store shall be adequately ventilated and the interior and all fittings therein shall be so constructed, covered or lined as to prevent exposure of any iron or steel or of any hard or gritty surface, or the entry, detaching or accumulating of any grit, iron, steel or similar substance.

Part 37 WELDING

Section 37.1 Ventilation

37.1 Where welding or cutting or soldering operations emit harmful fumes and gases, the employer shall ensure that ventilation is provided which will remove the fumes at the source required to maintain the airborne contaminants at or below the permissible levels as outlined in Part 11 of these regulations.

Part 43 HANDLING & STORAGE OF MATERIALS

Section 43.36 Construction

43.36 Bins used for storing highly combustible dry materials shall be of fire-resistant construction and provided with lids and an adequate ventilation system.

Part 45 PERSONAL PROTECTIVE EQUIPMENT

Section 45.17 Hazardous air

45.17 (1) Every employer shall ensure that when workers are or may be exposed to an oxygen deficient atmosphere or harmful concentrations of air contaminants, mechanical means of engineering design shall be utilized to prevent or to eliminate such hazardous conditions of exposure.

(2) Every employer shall ensure that where the prevention or elimination of such hazardous conditions is not reasonably practicable, or where the exposure results from temporary or emergency conditions only, every worker exposed shall wear approved protective respiratory equipment.

[EC2021-126, s. 3]

Part 49 ASBESTOS

Section 49.20 General

49.20 (1) An asbestos contractor shall ensure that each enclosure is equipped with a ventilation system for the purpose of asbestos work that is sufficient to ensure that the enclosure is under adequate negative pressure to prevent the release of respirable asbestos fibres into the air outside the enclosure.

(2) If exhaust ventilation equipment is used to contain asbestos fibres, an asbestos contractor shall ensure that the equipment is

(a) of a type designed and solely used for asbestos abatement procedures;

(b) equipped with a HEPA filter;

(c) maintained in good working condition and inspected regularly in accordance with the manufacturer’s specifications; and

(d) certified by a competent person not less than once a year as being able to function safely and effectively.

(3) An asbestos contractor shall ensure that the capacity of the ventilation system used in an enclosure is such that the air exchange rate is a minimum of 4 air changes per hour, and the differential pressure is at least 5 Pascals (-0.02 inches) of water.

[EC596/90, s. 1; EC2020-147, s. 8]