What is the difference between N95 respirators, surgical/medical masks, and non-medical masks?
Each type of mask is designed for a specific purpose:
Respirators such as N95 masks protect the wearer against exposure to airborne particles and aerosols in the surrounding environment when fitted and worn correctly. They also help to block exhaled respiratory droplets. Respirator masks are regulated by the government and must meet specific test and manufacturing controls.
Both medical-grade and commercial-grade N95 masks are sometimes in limited supply due to an increased need by front-line workers. You might see KN95 masks available for purchase. N95 (USA standard) and KN95 (China standard) respirators have similar design, filtration, performance, and material standards. Respirators approved under standards used in other countries may be acceptable for use in Canada, if the manufacturer can provide the evidence demonstrating testing to the appropriate standards. Verify with your jurisdictional OHS regulator if they may be used in your particular workplace.
Be aware that counterfeit respirators that do not provide sufficient protection have been reported for sale; ensure you only purchase from reputable vendors and manufacturers, and verify that the NIOSH approval number (for N95s) is legitimate. Visit Government of Canada – Fraudulent and unauthorized N95 respirators may not protect consumers against COVID-19 for more information.
NOTE: Masks with air release valves are ineffective at protecting others and are not recommended as they allow your exhaled air and respiratory droplets to escape from the mask.
Medical/Surgical Masks are a barrier to spreading respiratory droplets when the wearer breathes, talks, shouts, sings, sneezes, or coughs. Medical/Surgical masks are regulated by the government and must meet specific test and manufacturing controls. Unlike N95 respirators, they are not specifically designed to filter particles and aerosols from the surrounding environment. Medical/Surgical masks are most commonly used in healthcare settings but can also be purchased at many stores. They are typically made from lightweight pleated fabric, coloured on the outer surface (e.g., blue, yellow, or pink) and white on the inner surface, with a metal nose-clip and elastic ear loops. These masks are generally single use and should be changed and discarded when they become damp or soiled.
Non-medical masks (NMMs) limit the spread of respiratory droplets when the wearer breathes, talks, shouts, sings, sneezes, or coughs. They are most commonly used in the community and workplace along with other personal preventive practices (e.g., physical distancing, hand hygiene) to help prevent the spread of viruses. Non-medical masks are not regulated or tested; however, they do help to protect yourself and others from COVID-19 when they are well-constructed, well-fitted, and are properly worn, handled, and cared for.
Wear a non-medical mask when you are:
- required by your employer or local public health authority
- in crowded places or closed spaces with poor ventilation
- out in public and you might come into close contact with others
- interacting with people from outside your immediate household
When buying or sewing a fabric non-medical mask, the materials and design can make a difference in how effective it will be at limiting respiratory droplet spread. PHAC recommends three-layer masks: The inner and outer layers should be tightly woven material fabric, such as cotton or linen; the third (middle) layer should be a filter-type fabric, such as non-woven polypropylene. If three-layer masks are unavailable, consider layering several single-layer masks.
The mask should fit tightly over your nose, mouth and chin; a loose mask with gaps will be less effective. Make sure that the ear loops or head straps are secure.
Reusable fabric masks should be washed in hot soapy water and dried between each use, and when they become damp or soiled. Damaged masks will be less effective and should be discarded.
Visit these links for more detailed information about respirators, medical/surgical masks, and non-medical masks:
PHAC - COVID-19 medical masks and respirators: Overview
PHAC - COVID-19 medical masks and respirators: Information for health professionals
PHAC - Non-medical masks and face coverings: About
PHAC - COVID-19: How to safely use a non-medical mask or face covering
PHAC - Non-medical masks and face coverings: How to put on, remove and clean
World Health Organization (WHO): Coronavirus disease (COVID-19): Masks
CCOHS - Get the Facts on Masks
CCOHS - Video: How to choose a mask
CCOHS - Video: How to safely wear a mask
CCOHS - Video: How to care for a mask
CCOHS - Respirators, Surgical Masks, and Non-Medical Masks
CCOHS - Respirators - Respirators Versus Surgical Masks
CCOHS - Respirator Selection
CCOHS - Respirator Care
CCOHS - Respirators - Wearing a Respirator
CCOHS - Respiratory Protection Against Airborne Infectious Agents for Health Care Workers
Can KN95 respirators be used at work instead of N95 respirators?
Both medical-grade and commercial-grade N95 respirators are currently in short supply globally, and existing stock has been prioritized for the medical and other front-line service sectors. If your workplace normally uses N95 respirators for protection against fine particulate matter, you may be able to use a different type as long as it provides at least the same level of respiratory protection.
Occupational health and safety (OHS) legislation may state specific requirements for respiratory protection, including references to respirator test standards for design, filtration, performance, and materials. For example, N95 respirators meet a US-NIOSH test standard, while KN95s meet a China test standard. Similar test standards exist for Europe, Australia, Japan, etc. Respirators approved under standards used in other countries may be acceptable for use in Canada, if the manufacturer can provide the evidence demonstrating testing to the appropriate standards.
Always check directly with your jurisdictional OHS regulator for the exact legal interpretation, and to ask if respirators that meet a similar test standard may be safely used in your workplace sector for the type of work you are doing.
Do I have to wear a non-medical mask at work?
Wearing non-medical masks may be mandated by local government or public health authorities, based on the local rate of infection and other factors.
Under occupational health and safety (OHS) legislation, the employer is responsible for taking all reasonable precautions to protect the health and safety of their workers. This duty may include requiring workers to wear a non-medical mask in the workplace, in addition to other COVID-19 personal preventive practices such as physical distancing and frequent hand hygiene.
Workers are also responsible for using any personal protective equipment PPE (such as respirators) and other safety equipment required by the employer to protect their health and safety. While non-medical masks are not considered to be PPE (they are not regulated or tested by the government), they can help to prevent the spread of COVID-19 when well-constructed, well-fitted, and properly worn, handled, and cared for.
A risk assessment should be performed by the employer with the health and safety committee or representative to determine if non-medical masks are required, and to ensure that they do not create any new safety hazards.
Some workers may have pre-existing medical conditions that make wearing a mask difficult. In these cases, the employer and the worker must work together to find a reasonable accommodation.
Is it safe to wear a mask all day at work?
Masks are safe to wear for most people, and they help to reduce the spread of COVID-19.
The Public Health Agency of Canada (PHAC) has provided guidance on wearing non-medical masks in the community and workplace, including information about safety considerations and those who can’t wear masks. If a worker has health-related concerns about wearing a mask at work, they should consult with a medical professional and discuss with their employer.
Posts have circulated on social media claiming that wearing a mask can result in oxygen deficiency or carbon dioxide intoxication. This claim is FALSE and has been debunked by the World Health Organization (WHO) Mythbusters. While the air inside the mask may feel warm and humid, the oxygen and carbon dioxide levels are not affected. Learn more about fact-checking COVID-19 information.
If performing heavy tasks or working in a hot or humid environment, workers may experience heat stress, which is defined as the "net [overall] heat load to which a worker may be exposed from the combined contributions of metabolic heat, environmental factors (i.e., air temperature, humidity, air movement, and radiant heat), and clothing requirements."
Employers should have a workplace heat stress control program, to assess and manage the risk of heat stress. For example, workers may require more frequent rest or water breaks during hot weather conditions. Canadian occupational health and safety authorities generally use the Threshold Limit Values (TLVs) for heat as recommended by the American Conference of Governmental Industrial Hygienists (ACGIH). Note: in some health and safety legislation these may also be referred to as Occupational Exposure Limits (OELs).
The ACGIH has published guidance* on how to calculate heat stress exposure in units of WBGT (wet bulb globe temperature) degrees Celsius (°C). The calculation formulas include a ‘clothing adjustment factor’ for various listed clothing types, which may add 0 to +11 degrees Celsius (°C) to the final value.
While heavy or tightly woven work clothing may add to the worker’s heat load, studies have found that face masks and coverings have a ‘minimal effect on heat dissipation’ for the whole body. However, because the skin of the face has many nerves and temperature receptors, the worker may still feel as if they are experiencing an [overall] increase in heat load, due to localized lack of heat loss from the face.
The ACGIH does “not recommend any adjustment for the use of face coverings” and does not list a clothing adjustment factor for face masks; however, every workplace is unique, so the employer could still choose to apply a clothing adjustment factor. It is recommended that the employer consult with their workplace health and safety committee or representative, and jurisdictional OHS regulator.
* Refer to the current ACGIH “TLVs® and BEIs®" and “"Documentation of TLVs® and BEIs®" booklets for more detailed technical information.
For more information on Heat Stress, refer to these CCOHS OSH Answers:
Temperature Conditions - Hot
Temperature Conditions - Legislation
Hot Environments - Control Measures
Hot Environments - Health Effects and First Aid
Humidex Rating and Work
Thermal Comfort for Office Work
Can I wear a face shield instead of a mask?
Face shields should not replace the use of masks. They are useful for protecting the eyes, adding an additional layer of splash protection over a mask, and allowing full visibility of the wearers face. Face shields do not provide equivalent protection as respirator masks, medical / surgical masks, or non-medical masks. The large gaps at the sides and bottom of the face shield allow respiratory droplets to flow away from the wearer unimpeded. They also do not protect the wearer from potentially inhaling infectious respiratory droplets exhaled by others.
Visit CCOHS – COVID-19: Using Face Shields to learn more.
What PPE should I be using for COVID-19?
The personal protective equipment (PPE) required for protection against COVID-19 will depend on the workplace setting and the type of work being done.
For example, in healthcare settings where the risk of respiratory aerosols and close or prolonged contact with infected individuals is higher, PPE may include respirators or surgical masks, face shields, goggles, gowns, aprons, and gloves.
Situations where PPE may be considered for protection from COVID-19 include:
- Wearing gloves and other appropriate PPE as recommended by a chemical product’s safe work instructions or Safety Data Sheet (SDS), when cleaning and
- Wearing disposable gloves when cleaning blood or body fluids.
- If someone becomes symptomatic while at the workplace, they should wear a medical (surgical) mask if available. If not available, they should properly wear a well-constructed, well-fitting non-medical mask (if not already doing so).
- Where recommended or required by your local public health authorities.
In public settings, non-medical masks may be recommended or required. It is important to note that non-medical masks are not considered to be ‘PPE’, as they are not regulated or tested.
In all workplace settings, the PPE for existing occupational safety hazards and emergencies (other than COVID-19) should continue to be used, as directed by applicable laws and the employer.
The law is not always clear about who pays for PPE. It depends on the jurisdiction, and in some jurisdictions, it depends on the type of PPE required. For more information about OHS legislation and the requirement to provide PPE, always check directly with your jurisdictional OHS regulator for the exact legal interpretation.
Visit these links for more information about PPE:
PHAC – Coronavirus disease (COVID-19): Guidance documents
(These infection control documents for various sectors include guidance for COVID-19 PPE)
World Health Organization (WHO) - Personal protective equipment for COVID-19
CCOHS - Designing an Effective PPE Program
CCOHS - Personal Protective Equipment
CCOHS - Chemical Protective Clothing – Glove Selection.