This guide provides information on good practices to control the spread of COVID‑19 in the workplace. It is currently being updated to reflect changes in public health requirements.

Protecting workers

Under the Occupational Health and Safety Act (OHSA), employers must take every reasonable precaution to protect the health and safety of workers. This includes protecting workers from hazards posed by infectious diseases.

As part of fulfilling this obligation, you must assess your workplace to determine what you need to do to protect the health and safety of your workers, including how to minimize the risk of transmission of .

Read the guide on developing a workplace safety plan to:

  • help you understand the risks related to in your workplace
  • develop control measures
  • identify concrete actions you will take to make your workplace safer

Make sure you also follow any provincial requirements under the Reopening Ontario (A Flexible Response to ) Act and any local public health orders.

This document provides more specific information to help you make decisions about the use of masks in your workplace. It does not replace the Occupational Health and Safety Act and its regulations and should not be used as or considered legal advice. Health and safety inspectors apply the law based on the facts in the workplace.

control measures that use masks

A mask is a piece of equipment that covers the wearer’s nose, mouth and chin. It is fixed to the face with straps, ties or elastic, either behind the head or with ear loops. For , masks can be used in two ways at a workplace:

  • As source control: workers and visitors wear the mask to protect those around them. The mask is controlling the hazard at its source – the wearer
  • As personal protective equipment (PPE): workers wear the mask, along with eye protection, to protect themselves

Not all masks are suitable for both purposes. You need to consider how you will use the mask in your workplace and make sure to select a suitable type of mask.

Masks are important to reduce the risk in situations where other controls, particularly physical distancing, cannot be consistently maintained. However, masks should not be the only control measure or replace other control measures in your workplace.

To decide whether you will use masks as source control in your workplace or if they will be needed as PPE, you will need to assess all relevant factors in your workplace including how effective the source control masking and other control measures are at reducing risk.

Using masks as source control

Using masks as source control involves having workers, visitors and clients in the workplace wear a mask to protect those around them. This reduces the risk that the virus may be transmitted through the droplets of a potentially infectious person.

How effective this strategy is at preventing transmission depends on:

  • the type of mask(s) used
  • masks being worn properly and consistently by everyone

All employers should use masks as source control in their workplace, alongside physical distancing, wherever possible. If people in your workplace are not wearing masks because they cannot wear them for health or other reasons, you may need to implement additional control measures.

Source control masks should not be used as a substitute for physical distancing — both control measures lower risk and should be used together as much as possible.

Where physical distancing cannot be maintained, it is even more important that workers and visitors wear masks as source control. Surgical or procedure masks and respirators worn as part of PPE also work as source control.

Using masks as personal protective equipment

Masks worn as PPE are meant to protect the people wearing them. Correct use of PPE can help prevent some exposures, but it should not take the place of other control measures. Personal protective equipment must be used alongside other control measures.

To determine when PPE is needed, you will have to assess all the relevant factors in the workplace. This includes the effectiveness of other controls you already use.

Even with other controls in place, there are situations where PPE is needed to comply with your duty under the Occupational Health and Safety Act to take every precaution reasonable in the circumstances for the protection of workers.

PPE is an important control when workers are performing tasks that require them to work indoors or outdoors within two metres of an unmasked or improperly masked person without an adequate barrier (for example, Plexiglas, partition, wall).

To protect workers against in non-health care workplaces, PPE likely includes a surgical or procedure mask (or equal or greater protection) as well as eye protection (for example, face shield or goggles). Cloth masks are not suitable for use as PPE.

Surgical or procedure masks worn as part of PPE also work as source control and would normally meet any requirements for face coverings.

If you determine that personal protective equipment is needed in your workplace, you will need to:

  • train workers on the care, use and limitations of any PPE that they use
  • maintain your supply of PPE and make sure it is readily available to workers when they need it

Selecting masks

A mask should:

  • securely cover the nose and mouth
  • fit closely to the face without gaps

A nose piece that can be molded to conform to the face may be helpful to ensure a close fit.

Using a mask should not introduce any new health or safety hazards into the workplace such as masks getting caught in machinery or restricting vision.

When choosing what type of mask to use in your workplace, consider:

  • the purpose of the mask (source control and/or personal protective equipment)
  • mask qualities that impact your workers’ ability to wear it when needed, for as long as needed (for example, breathability, comfort and durability)

Existing performance standards, such as ASTM International mask standards, can help provide information on mask qualities such as breathability, filtration, and fluid resistance.

Masks used as PPE should be substantial enough to prevent droplet penetration.

Masks used as source control:

  • may be disposable or reusable
  • if made of cloth, should be made of at least two layers of tightly woven fabric, such as cotton or linen
  • should not have exhalation valves

Using masks properly

Make sure workers are trained on the type of mask they are using and its limitations. Workers should be told whether they are using masks as source control, PPE or both.

The effectiveness of a mask depends on the person wearing it correctly and consistently.

Those wearing masks should:

  • inspect their masks for tears, holes or other defects before each use
  • ensure their masks are clean and dry
  • wash their hands with soap and water or use alcohol-based hand sanitizer before and after touching the mask
  • put on and remove their mask by holding its ear loops or ties, rather than touching the part of the mask that covers their face
  • replace masks that become damp or dirty
  • wash cloth masks regularly with hot, soapy water and let dry completely before reuse
  • discard used masks that cannot be washed in a plastic lined garbage bin

Accessibility and accommodations

Not all people are able to wear masks, for example, because of a health condition. Develop a policy to address these situations before they arise.

Accommodations for someone who cannot wear a mask must not result in reduced protection for workers. Employers may need to implement other control measures to replace the protection that would be provided by the mask.

Different types of masks fit people differently. Workers may need to try various options to find a mask that works for them.

For people who need to have their faces seen, such as for lip reading, masks with clear panels are available for source control and PPE. Like all masks, these should securely cover the nose and mouth and fit closely to the face without gaps. If you choose to use a mask with clear panels as PPE, ensure that the mask is designed to meet this purpose.

Face shields

A face shield is a device that has a transparent window or visor supported in front of the face that provides a barrier of protection to the eyes, nose and lips.

Face shields can be used as PPE to provide eye protection. They are an alternative to other acceptable forms of eye protection, such as goggles or safety glasses with side shields.

Do not use face shields in place of masks. There is insufficient evidence that face shields used without a mask are suitable for use as source control masking or PPE.

A mouth shield, or other device that provides a barrier of protection to only the mouth and nose, is not a face shield or a mask and should not be used as source control or as PPE.