Guidance for wearing masks

Last updated 4/19/2021.

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People in shop wear masks and distance

A mandatory mask-wearing requirement for Colorado first went into effect in July 2020 and recently was amended in Executive Order D 2021 079 on April 3, 2021.

The updated Executive Order will continue to require mask-wearing for all counties in schools (including extracurricular activities), child care centers, indoor children’s camps, public-facing state government facilities, emergency medical and other healthcare settings, personal services and limited healthcare settings as defined by Public Health Order (PHO) 20-36, congregate care facilities, prisons, and jails. In counties with one-week disease incidence rates over 35 per 100,000 -- which are known in Dial 3.0 as blue, yellow, orange, red, and purple counties -- masks must also be worn in public indoor settings where 10 or more unvaccinated individuals or individuals of unknown vaccination status are present.

Local communities may have additional mask restrictions.

Fast facts

The order requires people in Colorado who are 11 years and older to wear a mask over their noses and mouths when entering or within the following public and private settings:

  1. Preschool through grade 12 schools (including extracurricular activities), child care centers and services, and indoor children’s camps;
  2. Public areas of state government facilities, and areas in state government facilities where members of the public come into contact with state government employees;
  3. Congregate care facilities, including nursing facilities, assisted living residences, intermediate care facilities, and group homes;
  4. Prisons;
  5. Jails;
  6. Emergency medical and other healthcare settings (including hospitals, ambulance service centers, urgent care centers, non-ambulatory surgical structures, clinics, doctors’ offices, and non-urgent care medical structures);
  7. Personal services, as defined by Public Health Order (PHO) 20-36; and
  8. Limited healthcare settings, as defined by PHO 20-36.

In counties with one-week disease incidence rates in excess of 35 per 100,000, masks are required to be worn when entering or within public indoor spaces where 10 or more unvaccinated individuals or individuals of unknown vaccination status are present.

People who do not have to wear a mask include:

  • People who are 10 years old and younger.
  • People who cannot medically tolerate a face covering.
  • Children ages 2 and under should NOT wear masks or cloth face coverings.

Research shows that people who have no symptoms can spread COVID-19. Wearing a mask helps minimize the spread of the virus. Find step-by-step instructions for making homemade masks at the BBC’s website.

What is the most recent science behind universal mask-wearing?

Masks should:

  • Be clean and in good repair.
  • Fit snugly, but comfortably against the side of the face.
  • Be secure.
  • Include multiple layers of fabric.
  • Allow for breathing without restriction.
  • Be able to be laundered and machine dried (if reusable).
  • Be on the wearer's face.
  • Be laundered on a daily basis (if reusable) or thrown away after use (if disposable).

Masks should not:

  • Have anything hanging off the facial covering that would create a food safety hazard.
  • Have holes or tears. 
  • Be shared with others.
Icon of person wearing a mask

Other tips:
  • Wash your hands before and after putting a mask in place.

  • Do not touch the mask again until you remove it.

  • For better protection, you can wear a cloth mask with multiple layers, or you can wear a disposable mask underneath a cloth mask. The second mask should push the edges of the inner mask against your face.

  • Do not wear two disposable masks at the same time. Disposable masks are not designed to fit tightly and wearing more than one will not improve fit.

  • There is no need to combine a KN95 mask with another mask in most non-healthcare settings. Only use one KN95 mask at a time.

  • Masks should be positioned so that there is no need to adjust or otherwise touch the face frequently.

  • If your mask becomes soiled or hard to breathe through, you should remove and not wear again until laundered.

  • Remove your mask to eat and drink and if it is still in good repair, you may continue to use it.

  • Cloth masks should be carefully folded so that the outer surface is held inward and against itself to reduce contact with the outer surface during storage.  The folded mask can be stored between uses in a clean sealable paper bag or breathable container.  Store your mask with your personal items.

For businesses

Sign with two people wearing masks. Says that Mask required to enter per state order.

Mask required sign (8.5 x 11) Blue   | Red      

(Spanish) Letrero de tapabocas obligatorios (8.5 x 11) Azul   | Rojo  

About the Executive Order

Questions & answers about the statewide mandatory mask order (PDF)

Includes questions and answers about masks in schools.

  • The mask order requires people in Colorado over 10 years old to wear a mask over their noses and mouths:

    • For all counties: in schools (including extracurricular activities), child care centers, indoor children’s camps, public-facing state government facilities, congregate care facilities, prisons, and jails, emergency medical and other healthcare settings, personal services, and limited healthcare settings.

    • In counties with one-week disease incidence rates in excess of 35 per 100,000 -- which are known in Dial 3.0 as blue, yellow, orange, red, and purple counties -- masks must also be worn in public indoor settings where 10 or more unvaccinated individuals or individuals of unknown vaccination status are present.

  • The statewide mask order does not require masks outside. Local communities may have additional mask restrictions so people should check local ordinances. Additionally, the statewide mask order does not require people to wear a mask if they are:

    • Alone in a room in a public indoor space.

    • Hearing-impaired or otherwise disabled or who are communicating with someone who is hearing-impaired or otherwise disabled and where the ability to see the mouth is essential to communication.

    • Seated at a food service establishment.

    • Exercising alone or with others from their household, and a mask would interfere with the activity.

    • Receiving a personal service where the temporary removal of the mask is necessary to perform the service.

    • Entering a business or receiving services and are asked to temporarily remove a mask for identification purposes.

    • Actively engaged in a public safety role such as law enforcement, firefighters, or emergency medical personnel that prevents the user from safely wearing a mask. .

    • Officiating or participating in a life rite or religious service where the temporary removal of a mask is necessary to complete or participate in the life rite or religious service.

    • Giving a speech for broadcast or an audience, if the audience is at least 25 feet away from the speaker. The audience members must wear masks.

  • Local communities may have additional mask restrictions.

  • None of the vaccines are approved for children under 16 years old. The Moderna and Janssen (Johnson & Johnson) vaccines are only approved for adults 18 and older.
  • Until a vaccine is approved for children 16 and under and widely available, schools should still implement and layer prevention strategies and should prioritize universal and correct use of masks and physical distancing.
  • The latest CDC evidence suggests that many K–12 schools that have strictly implemented prevention strategies have been able to safely open for in-person instruction and have remained open during the pandemic. Find the CDC’s latest operational strategy for K-12 schools, released March 19, 2021.

  • The mandatory statewide mask Executive Order first went into effect on July 16, 2020, and Governor Polis has extended it repeatedly since then. The Governor’s Office released the most recent amendment to the Executive Order on April 3. An extension of the Executive Order takes effect for a maximum of 30 days. The Governor, public health experts, and the Governor’s legal team review every Executive Order before expiration. We are closely monitoring disease transmission, hospitalizations, and vaccination rates, and will consider these factors prior to the Executive Order’s expiration.

  • For the mask order, “public indoor space” means a publicly or privately owned, managed, or operated, enclosed indoor area that is accessible to the public, is a place of employment or is an entity that provides services. Public indoor space does not mean a person’s residence, including a room in a motel or hotel or a residential room for students at an educational facility. Public indoor spaces include but are not limited to: 
    • Government buildings, including correctional and detention facilities.
    • Nonprofits.
    • Transportation.
    • Houses of worship.
    • Private country clubs or social clubs.
    • Grocery stores.
    • Hair salons.
    • All offices, lobbies, elevators.
    • Malls, retail stores.
    • Indoor businesses, common areas.
    • Medical facilities, nursing homes.
    • Restaurants (if not seated).
    • Libraries.
    • Museums.
    • Theaters.
    • Casinos.
    • Gyms, including areas around indoor pools, but not while swimming in the pool.
    • If a business or entity provides services or goods both indoors and outdoors at a single location, a mask must be worn in the indoor portion of that business or entity.
    • All enclosed indoor areas, whether publicly or privately owned or managed, except an individual’s residence.

  • No, the mask order does not apply to anyone’s personal residence. However, guidance from the CDC advises limiting the number of guests, keeping physical distance, and wearing masks when socializing in your home with people outside your household if you have not been vaccinated. People who have been vaccinated may go without masks if they are socializing with one other household at low risk of severe disease, but the CDC still recommends avoiding large private gatherings, especially indoors.

  • Yes, Executive Orders and public health orders have the force of law. People who do not comply with the Executive Order may be subject to civil or criminal penalties.

  • Children 10 years and younger are not required to wear masks because the evidence so far has shown that children in this age group are less likely to spread COVID-19 than older children and adults.

  • Essentially, this means a person who has trouble breathing or anyone who is unconscious, incapacitated, or otherwise unable to remove the mask without assistance, according to the Centers for Disease Control and Prevention. Read more from the CDC about other reasons face coverings may not be possible in every situation or for some people. 

  • You do not need a written exemption.
  • You may tell the establishment that you cannot medically tolerate a mask. But please be aware that if you cannot medically tolerate a mask, you should consider limiting any visits to businesses to protect yourself and others. If you need help getting groceries or other necessities, you can call 211 to be connected to local resources that may be able to help you.
  • Under the Americans with Disabilities Act, businesses may offer reasonable accommodations for individuals with medical disabilities that make it so that they can’t wear a mask. This could include offering delivery or call-ahead curbside pickup instead of allowing entry into the building. More information.
    • The CDC recommends businesses post a sign outside that says “Masks Required” and provide a phone number and email address for someone to contact should they be unable to use a mask.

  • Mental health providers may use their clinical judgement to determine if it is medically or clinically necessary for a patient to temporarily remove their mask during an in-person appointment. Mental health providers must wear masks at all times, excluding the few exceptions listed at the beginning of this document, or if temporary removal is necessary to perform the medical service.

  • Yes. A business may exclude an individual with a disability from entering an establishment or participating in an activity or service if that individual’s presence would result in a direct threat to the health and safety of others. This determination must not be based on generalizations or stereotypes, and must be based on an individual assessment. This does not apply to health care related places of public accommodation.

  • Places of public accommodation should make reasonable efforts to allow individuals with a disability (i.e. breathing issues, facial disfigurement, etc.) that prevent them from wearing a mask to use a place of public accommodation, unless the place of public accommodation can demonstrate that it would cause an undue burden or that it would require any additional expense that would not otherwise be incurred.

  • Reasonable accommodations may include a virtual experience rather than in-person, curbside pickup, outdoor seating rather than indoor, rental equipment to do an activity at home, a room to do an activity alone, or special hours to access goods or services alone. Some businesses, like airlines, may not be able to accommodate an individual who is unable to wear a face covering. In those situations, a business is still not required to allow an individual to enter an establishment without a mask.

  • For more information, see: Civil Rights Guidance for Employers and Places of Public Accommodation during Safer at Home and in the Vast, Great Outdoors,   Guidance to Employers and Places of Public Accommodation Regarding Equal Opportunity Employment and Reasonable Accommodations Due to The Presence of COVID-19, and The ADA and Face Mask Policies.  

  • Businesses or facilities should err on the side of assuming that people entering their indoor site are unvaccinated. With one in six Coloradans fully vaccinated, most indoor public settings like grocery stores, retail stores, and gyms will need to require mask wearing.

  • By continuing to wear masks in public indoor settings around others, we can more safely enjoy the activities we love and keep our economy open. Every community has been impacted differently by this pandemic, and we want to make sure this order reflects that.
  • This modified mask order is a step toward the light at the end of the tunnel. It acknowledges  a transition away from requirements for those counties in Level Green with very low transmission, with 35 cases or less per 100,000 people, and the great achievement they have made toward ending the pandemic.
  • As of April 1, 2021, more than 1 million Coloradans have been fully vaccinated against COVID-19, and more than 1.6 million Coloradans have received at least one dose of COVID-19 vaccine. Because of these developments in statewide vaccination, the state’s role in mandating statewide restrictions is lessening and the role of local communities to manage transmission is increasing.

Activities and events

  • The Executive Order does not state that you must wear a mask outdoors unless you are waiting on public or non-personal transportation.
  • However, it is strongly recommended to wear a mask whenever you cannot keep a safe distance (at least 6 feet) from other people. We encourage you to wear a mask whenever you are in crowded spaces, either indoors or out.

  • In counties with one-week disease incidence rates in excess of 35 per 100,000 (Levels Blue through Purple), you must wear a mask when entering any kind of store where 10 or more unvaccinated individuals or individuals of unknown vaccination status are present.
  • With one in six Coloradans fully vaccinated, most indoor public settings like grocery stores, retail stores, and hardware stores will need to require mask wearing.

  • In counties with one-week disease incidence rates in excess of 35 per 100,000 (Levels Blue through Purple), you must wear a mask when entering or exiting an indoor restaurant where 10 or more unvaccinated individuals or individuals of unknown vaccination status are present. You may take the mask off when you are seated but must put it back on when you stand up to use the restroom or to leave.

  • In counties with one-week disease incidence rates in excess of 35 per 100,000 (Levels Blue through Purple), this applies to any indoor setting open to members of the public where 10 or more unvaccinated individuals or individuals of unknown vaccination status are present. If there are specific religious spaces where members of the public are not allowed, such as spaces only accessible by clergy, then this does not apply to those limited settings.

  • Clergy are not required to wear masks while officiating at a religious service.

  • Individuals who are officiating or participating in a life rite or religious service may temporarily remove a mask if doing so is necessary to complete or participate in the life rite or religious service.

  • You may remove your mask if delivering a speech to an audience. Please put your mask back on as soon as you are able. If you remove your mask to deliver a speech, please note that we ask performers to be 25 feet away from the audience.

  • Unless it interferes with the integrity of the proceedings, mask-wearing is required. However, we recognize that the judicial branch is independent of the executive branch and may need to propose rules specific to trials (e.g., witnesses) that are reasonable and may require temporary removal of a mask. Judges are permitted to set rules for both their courthouse and individual trials.

  • In counties in Levels Blue through Purple, if 10 or more unvaccinated individuals or individuals of unknown vaccination status are present, masks are required in congregate living settings. In large congregate living settings, only individuals who regularly sleep in the same room are considered members of the same household. As such, common rooms are indoor spaces where you may be around non-household members, so you must wear a mask in those areas.

  • In all counties, masks are required in congregate care facilities, including nursing facilities, assisted living residences, intermediate care facilities, and group homes.

At school

  • We encourage masks over the nose and mouth for students 3 to 10 years old, including during in-person instruction (including sitting at desks) and extracurricular activities, unless the student has a medical intolerance, disability, or education reason for not wearing a mask.
  • Masks over the nose and mouth are required for students ages 11 years and older, including during in-person instruction (including sitting at desks) and extracurricular activities, unless the student has a medical intolerance, disability, or education reason for not wearing a mask.

  • Staff and students do not need to wear masks while eating, but they should continue to social distance. 
  • Students ages 3-10: The Executive Order does not require masks for this age group. If local orders require masks for this age group, check the local order for clarification on requirements in educational settings. 
  • Students ages 11 and older: A mask is not required while outside for recess or exercise, as long as 6 feet of distancing can be maintained. 
  • Masks may be temporarily removed if they interfere with special educational needs, such as hearing impaired students and for English learners.  
  • Masks should be removed during naptime.
     

  • Parents are encouraged to work with their school health services team or COVID-19 school coordinator to discuss their child’s medical needs.

  • The requirement to wear a mask does not apply to individuals who cannot medically tolerate a mask. In general, this means a person who has trouble breathing or who is unconscious, incapacitated, or otherwise unable to remove the mask without assistance. Parents are encouraged to work directly with their child’s medical provider to determine the health needs of their child in the school setting. 

  • The process used to verify “medical intolerance” is determined at the school or school district level. Parents are encouraged to work with their school health services team or COVID-19 school coordinator to discuss their child’s medical needs. 

  • Schools are encouraged to establish a process for communicating essential information to school staff while maintaining confidentiality. 

  • It is becoming increasingly evident that masks are an inexpensive and easy way to limit disease spread. Together, masks and distancing offer a greater measure of protection. We strongly encourage all people in Colorado to practice the Big 3: Wear a mask. Wash your hands. Keep your distance.
  • However, it is possible to spread or be exposed to COVID-19 even while wearing a mask.
  • Masks are most important when distancing is difficult. People who are unable to wear a mask should take other measures to reduce their risk, including distancing, frequent hand washing, and disinfecting surfaces.
  • When distancing, people tend to speak louder to project their voices further, which is yet another reason why masks and distancing work together for the best protection.
     

  • Masks over the nose and mouth are required for students ages 11 years and older, including during in-person instruction (including sitting at desks) and extracurricular activities, unless the student has a medical intolerance, disability, or education reason for not wearing a mask.
  • If a school or school district is not abiding by these requirements, a parent or community member should contact the county local public health authority.

Sports and recreation

  • In counties with one-week disease incidence rates in excess of 35 per 100,000 (Levels Blue through Purple), mask-wearing requirements apply to all groups of 10 or more people who are unvaccinated or whose vaccination status is unknown indoors, including people exercising. If you are in an indoor room with at least nine other patrons who are not a part of your household, then you need to wear a mask. You may remove it temporarily if you need to catch your breath or safely perform an activity, but wear a mask as much as feasible.
  • With one in six Coloradans fully vaccinated, most indoor public settings like grocery stores, retail stores, and gyms will need to require mask wearing.

  • In counties with one-week disease incidence rates in excess of 35 per 100,000 (Levels Blue through Purple), masks should be worn while playing indoor sports (unless you have a medical exemption) when there are 10 or more people in a room who are unvaccinated or whose vaccination status is unknown. You may remove the mask temporarily to catch your breath if needed, or if you can’t wear appropriate safety equipment while wearing the mask. Wear a mask as much as feasible.

  • The order applies to indoor sports of all levels, including youth and adult recreation leagues, high school sports, as well as college intramural and NCAA sports.

  • You should take your mask off while swimming in the pool, but you must put it back on while you are not swimming but in the pool area.

  • Lifeguards may remove their mask if they need to do so in order to safely perform an activity.

Enforcement

  • If you refuse to wear a mask as required in the Executive Order, you are violating a Colorado law and may be subject to civil or criminal penalties. You may also be in violation of county or municipal ordinances and subject to a ticket and/or fine.
  • If you are asked to leave a store due to failure to wear a mask, and you refuse, you may be charged with trespassing.

A licensed business is at risk of losing its license.

  • Businesses should refuse service to individuals not wearing masks when they are required. If a patron becomes combative or refuses to leave, contact local law enforcement, who can help defuse the situation or intervene if the individual fails to comply.

In the workplace

  • What if I’m alone in my office with the door closed? 
    • If you are the only person in a room with the door closed, then you may remove your mask.
  • What if I am sitting at my cubicle spaced 6 feet away from my closest neighbor? 
    • In counties with one-week disease incidence rates in excess of 35 per 100,000 (Levels Blue through Purple), you must wear a mask in any shared, indoor space that accommodates at least nine people outside your household who are unvaccinated or whose vaccination status is unknown. This includes spaces divided by physically distanced cubicles. We continue to encourage employers to prioritize work from home. 
  • What if I am in the elevator? Break room? Hallway?
    • In counties with one-week disease incidence rates in excess of 35 per 100,000 (Levels Blue through Purple), you must wear a mask in common areas like hallways, elevators, or breakrooms if there are 10 or more people who are unvaccinated or whose vaccination status is unknown. If a common space is used for consuming meals (i.e., break rooms), follow restaurant guidance for that setting. 

  • The Executive Order states indoor businesses must refuse service to people who are not wearing masks when they are required. 
  • Businesses must post signs at entrances that instruct customers they must wear a mask when entering or moving around inside the business. 
    • The Centers for Disease Control and Prevention recommends adding a phone number and email address people unable to use a mask can contact. This will reduce the potential that an employee will have to manage a situation with an uncooperative, un-masked person.
  • Businesses should consider implementing alternatives to in-person service, such as curbside pick-up, contactless delivery, or assistance with services/products available online.

  • No. Plexiglass barriers may not substitute for masks. They may provide an added benefit, but cannot be used as a substitute.

Local governments

  • Yes, counties and municipalities can adopt stricter standards than the statewide order.

Your local public health agency is a good source of information for orders within your county.

Mask basics

  • You should wear something that covers your nose and mouth --  a cloth face covering or a disposable mask.

  • Make sure your mask fits snugly against your face. Gaps can let air with respiratory droplets leak in and out around the edges of the mask.

  • Masks should be made up of multiple layers of fabric or material. A mask might be too thin or porous if you can easily feel your breath in front of you (or can easily blow out a candle) while wearing it, or if you can easily see through it when stretched. 

  • Masks with exhalation vents should not be used, as infectious droplets can be exhaled through the vent.

  • A nose wire -- a metal strip along the top of the mask -- can help a mask fit snugly and prevent any gaps. A mask fitter or brace can also prevent air from leaking around the edges of the mask.

  • You can check for gaps by cupping your hands around the outside edges of the mask. Make sure no air is flowing from the area near your eyes or from the sides of the mask. If the mask has a good fit, you will feel warm air come through the front of the mask and may be able to see the mask move in and out as you breathe.

  • The best mask for you is one you can wear comfortably and consistently. Any mask that covers the nose and mouth will work.

  • We recommend that the wearer be able to remove and put on their own mask without assistance.

  • For additional protection, you can wear a disposable mask under a cloth mask. The cloth mask should push the edges of the inner mask against your face.

  • You can also wear a cloth mask that has multiple layers of fabric built-in.

  • We don’t recommend wearing two disposable masks at the same time. Disposable masks are not designed to fit tightly and wearing more than one will not improve fit.

  • If you are using a KN95 mask, there is no need to wear another mask at the same time. Only use one KN95 mask at a time.

  • No, a face shield is not an acceptable substitute for a cloth or disposable face covering.

  • Masks and face-coverings are interchangeable terms. Cloth masks or face coverings or disposable masks are acceptable as long as they cover the nose and mouth.
  • People may wear surgical or other, more protective masks, but we encourage people to preserve medical masks for health care and other essential workers.
  • While at work, people should wear masks appropriate to the business in which they work.

  • It is becoming increasingly evident that masks are an inexpensive and easy way to limit disease spread. Together, masks and distancing offer a greater measure of protection. We strongly encourage all people in Colorado to practice the Big 3: Wear a mask. Wash your hands. Keep your distance.
  • Masks are most important when distancing is difficult. People who are unable to wear a mask should take other measures to reduce their risk, including distancing, frequent hand washing, and disinfecting surfaces.
  • When distancing, people tend to speak louder to project their voices further, yet another reason why masks and distancing work together for the best protection.

  • Masks should:
    • Fit snugly but comfortably against the side of the face.
    • Be secured with ties or ear loops.
    • Include multiple layers of fabric.
    • Allow for breathing without restriction.
    • Be able to be laundered and machine dried without damage or change to shape.
    • Cover your nose and mouth. Wearing a mask under your nose or chin doesn't work. 

  • Wash your cloth mask regularly with your regular laundry.

  • Try not to touch your eyes, nose, or mouth when putting on and taking off your face covering. Hold the mask by the corners and avoid touching the front or back of it. Wash your hands before putting your mask on and right after you remove it. 

  • The CDC and CDPHE web pages are excellent resources.

  • No. Science shows that wearing a mask isn’t harmful.

  • According to the Mayo Clinic Health System, “for many years, health care providers have worn masks for extended periods of time with no adverse health reactions ... there is no risk of hypoxia, which is lower oxygen levels, in healthy adults. Carbon dioxide will freely diffuse through your mask as you breathe.”

  • A cross-over study showed wearing a three-layer nonmedical face mask was not associated with lower oxygen levels among older participants doing normal activities.

  • Another study showed mask-wearing had no detrimental effect in exercise performance, blood oxygenation, or tissue oxygenation among healthy individuals undergoing vigorous exercise. 

  • The state still encourages mask-wearing in any setting where you may be interacting with people outside your household, especially indoors. Masks work well to protect people from all forms of COVID-19, including variants.

  • Many different peer-reviewed studies show that masks help prevent the spread of COVID-19. Masks work by reducing the amount of infectious respiratory particles in the air. More studies on masks are being added to the scientific literature every month.

  • Masks appear to help keep the person wearing the mask from spreading COVID-19 to others by reducing how many and how far infectious particles can spread when a sick person exhales, speaks, coughs, or sneezes. 

  • Masks also appear to partially protect the person wearing the mask, especially from severe infection. Masks may partially filter infectious particles and possibly reduce the amount of virus people breathe in. They may also keep people from touching their faces

  • Individuals are thought to be best protected when both they and most others in their community wear masks.

  • Mask-wearing works best when masks fit well. For more information, read a CDC report about how mask fit affects viral transmission.

  • Read a CDC editorial advocating for mask-wearing

  • These laboratory studies examine how well masks filter infectious particles in the laboratory setting or how COVID-19 transmission is prevented or limited among laboratory animals:

    • Fabric and homemade cloth masks, particularly tightly-woven and multi-layered ones, partially filtered out infectious respiratory droplets and aerosols in these two studies: Konda 2020 and Davies 2013.

    • Regular surgical face masks (not N95 masks) significantly reduced the amount of influenza virus and coronavirus nucleic acid detected in exhaled respiratory droplets and aerosols of infected individuals.  

    • Hamsters simulated to wear masks had a lowered risk of COVID-19 infection or less severe COVID-19 disease compared to hamsters who were not simulated to wear masks when exposed to the virus. 

  • These studies observe how masks may reduce the risk of getting sick from COVID-19 during individual outbreaks or potential outbreaks (i.e., natural “experiments”):

  • These studies demonstrate decreasing COVID-19 incidence after increases in mask use or mask mandates across a community or system:

  • Additional evidence that supports mask-wearing can be found in a recent CDC scientific brief