Masks are most effective when fitted, worn and handled correctly. They act as a barrier and, in combination with other measures, can help prevent the spread of respiratory infections.
Last updated: November 6, 2023
The information on this page is for the public. Health care professionals should follow the precautions in place at your site of work.
When someone with a respiratory infection coughs, sneezes, sings, speaks or breathes, they release small particles that can spread the virus to others who are nearby. Some people can spread the virus when they have very mild symptoms or are unaware that they have a respiratory infection.
Masks are one of many layers of protection that can help prevent the spread of respiratory infections such as COVID-19.
In this section
How to wear a mask
Types of masks
When to wear a mask
Children and masks
Cleaning and disposing of masks
Environmental impacts of disposable masks
All masks should fit comfortably over the mouth and nose with no gaps around the face. Wearing a mask should be combined with other important protective measures such as staying up to date with COVID-19 and influenza vaccines, staying home when sick, and regularly cleaning your hands.
- The mask should be held snugly in place with ties or ear loops.
- Masks that are uncomfortable and need frequent adjustment are less effective.
- Respirators with valves or masks with valves should not be used because they allow the breath of the wearer to escape, which could spread infectious particles to others.
- Masks should only be used by one person and should never be shared.
- Wash or sanitize your hands before putting on your mask and after taking it off.
Please see the How to wear a facemask poster for information on how to properly put on and take off a mask.
Different types of masks include certified respirators (e.g., N95, KN95, or CAN95), certified medical masks (e.g., ASTM F2100, EN 14683), non-medical disposable masks, and cloth masks.
All types of masks help reduce transmission of respiratory infections when they fit comfortably over the mouth and nose with no gaps around the face.
In settings where a large proportion of the population is at risk for severe outcomes of a respiratory infection, like influenza or COVID-19 (e.g. long-term care facilities, shelters), respirators and medical masks may provide better protection than other masks when worn correctly and consistently.
Choose the mask that is best for you, depending on your ability to comfortably wear it, what you can afford, and your individual risk.
Respirators are certified by national agencies such as the Canadian Standards Association and the US National Institute for Occupational Safety and Health. They may have a cup shape, flat fold, or duckbill shape. Respirators can filter small particles when they fit closely over the mouth and nose with no gaps around the face.
In healthcare and other workplace settings, respirators are specially fitted to each person, but in public settings, this is not needed. An ideal respirator is comfortable and does not require frequent adjustments.
Respirators are available in adult and child sizes. Facial shape, size, and hair can affect the quality of the fit. Respirators with valves allow the breath of the wearer to escape, which could spread infectious particles to others.
To ensure that respirators have been approved in Canada look for a US National Institute for Occupational Safety and Health TC-84A-####n number stamped on the mask, or products marked as meeting the Canadian Standards Association Z94.4.1, GB 2626-2019, KMOEL–2017-64 or EN 149-2001 standards.
These masks are also known as surgical or procedure masks and, like respirators, they are certified by national agencies. They can be made from different materials but commonly have a pleated or folded look and are rectangular when flat.
Medical masks are available in adult and child sizes. To improve the fit of medical masks they can be folded, knotted, worn with a mask fitter, or worn with a cloth mask overtop.
To ensure that medical masks have been approved in Canada look for a medical mask that has ASTM F2100 or EN 14683 on the packaging label.
Non-medical disposable masks often look like certified medical masks, but unlike certified medical masks, they have not been tested by national agencies for filtration effectiveness. As with medical masks, their fit can be improved by knotting ear loops, tucking in the side pieces, wearing under a cloth mask, or using a mask fitter.
Cloth masks can be purchased or homemade. They should be made from three layers of tightly woven, breathable fabric. As with other masks, cloth masks are most effective when they fit comfortably over the mouth and nose, with no gaps around the face. Some cloth masks are designed with a pocket for a filter and may provide more protection when the filter is used.
Face shields do not replace masks but can provide additional protection when worn with a mask. Mouth shields are not recommended.
When communicating using lip-reading, when visual facial cues are essential, or when people may be unable to wear a mask due to a medical condition a face shield may be an alternative to no mask.
Some face shields provide better protection than others. When needed, use face shields that wrap around your face and extend below the chin or hooded face shields.
- Disposable face shields should only be worn once.
- Reusable face shields should be cleaned and disinfected after each use.
- Clear masks that cover the nose and mouth are another option when visual communication is necessary.
Wear a mask in places where it is required, if you are sick and cannot stay away from others, or as a personal choice.
Some people may choose to continue to wear a mask because they are more comfortable wearing a mask or because they, or someone in their family, may be at higher risk and want to take extra precautions.
Be respectful of everyone whether they choose to wear a mask or not. It is important to be kind and respectful of other's choices.
Masks can offer an important layer of protection if someone has symptoms of a respiratory infection.
Children under two years of age should not wear a mask or any face covering, including visors and eye protection. These face coverings will make it difficult for a baby to breathe because their airways are still small. There is also a risk that parts of the mask, visor or eye protection can come off and become a choking hazard.
Respirators, medical masks, and non-medical disposable masks are typically sold as single use, and they should be changed when they become visibly dirty, damp, or damaged. You can reuse masks but they don't retain the same efficacy. They should not be cleaned because it will damage the protective layers and reduce their effectiveness. Cloth masks should be cleaned frequently. Wet masks are ineffective and should be replaced.
- Clean your hands before putting on your mask and after taking it off.
- Put masks that will not be reused in a garbage bin.
- When emptying garbage bins, do not touch used masks or tissues with your hands.
- Cloth masks can be washed by hand or in a washing machine. Dry the mask completely before use. Be aware that some fabrics may shrink in the dryer, affecting mask fit.
- Any damage, fabric breakdown, or change in fit will reduce the protection of cloth masks.
To reduce the environmental impacts of disposable masks
- Reuse your mask as long as it remains dry, has no visible dirt or stains, and a good fit can be maintained. Change your mask if it becomes damaged or soiled.
- Ensure masks that are ready for throwing away are placed securely in the garbage so they do not end up in waterways or other natural environments
- Cut the ear loops before disposing of a mask
- Check that spare masks (e.g., in the car, backpack, pocket etc.) are held securely until needed to avoid creating accidental mask litter
- Do not flush masks down the toilet
- Do not put masks in your municipal composting or recycling bin
- Some manufacturers offer recycling collection points for used masks in some communities.