Masks prevent people from getting and spreading COVID-19. Every Californian must wear a mask or face covering in all public and workplace settings where there is a high risk of exposure. This is more important than ever with new, more easily transmitted variants of COVID-19 on the rise.

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How masks help stop the spread

Coronavirus spreads when an infected person coughs, sneezes, sings, talks, or breathes within 6 feet of others. You may be infected even if you feel well.

To prevent infection, you must cover your nose and mouth when outside your home. Wearing a mask is required statewide. It can slow the spread of COVID-19 by limiting the release of virus into the air.

Masks can reduce your exposure to infectious droplets through filtration. It also reinforces physical distancing, and shows you care about the health of others.

Choosing a mask

Less effective
  • Cloth masks with 1 or 2 layers
  • Bandana
  • Gaiter
Better
  • Fitted medical mask
  • Cloth mask with 3 layers
  • Double mask (medical + cloth)
  • KN95
Best
  • N95

Cloth masks

Cloth masks can work well if they are tight-fitting and made of materials that filter out small particles.

Good cloth masks have:

  • Two layers of tightly woven cotton with a third layer of non-woven fabric. The third layer could be a mask filter insert, or a synthetic fabric such as polypropylene.
  • Nose wires to reduce gaps around the nose
  • Adjustable ear loops or headbands to reduce gaps around the face
Woman wearing a cloth mask.

Masks without these properties should not be used if other options are available.

Examples of less effective masks are:

  • Two-layer cotton masks
  • Bandanas
  • Gaiters

Medical masks

Medical masks (also called surgical masks) include many types of loose-fitting disposable masks. The fit of a medical mask can be improved with a simple modification or by using a mask brace .

Buy medical masks with:

  • Three layers of non-woven material
  • An adjustable nose bridge

Surgical masks with ties may provide a closer fit than ear loops.

Woman wearing a medical mask.

KN95 respirators

KN95s are respirators made designed to provide a specific level of protection. But KN95 respirators have not gone through the same strict testing as N95s. 

Testing of KN95s has shown that some models are not effective. If you do choose to use a KN95, we recommend finding a KN95 that has been tested by NIOSH and has a minimum “filtration efficiency” of 95% or higher.

N95 respirators

When they fit well, N95 respirators are highly effective in preventing the spread of COVID-19.

Make sure they are NIOSH-approved (have a TC-84A-XXXX number printed on the respirator). Choose a size and model that fits your face and has no gaps. Test it by doing a seal check to make sure it fits.

Picture of N95 mask.

As the availability of respirators increases, individuals may choose to wear them instead of other options, particularly in settings where greater protection is needed.

If you wear an N95 respirator, you should not wear an additional face covering over or under the respirator, as it can interfere with the seal to the face.

How to wear a mask

For your mask to be effective, it must be worn properly and consistently. 

  • Wear your mask so it completely covers the nose and mouth
  • Wash your hands or use hand sanitizer before putting on your mask
  • Put the mask over your nose and mouth and secure it under your chin
  • Fit the mask snugly against the sides of your face, slipping the loops over your ears or tying the strings behind your head
  • Make sure you can breathe easily
  • Try not to touch the mask when wearing it. This can transfer virus to your hands.
  • If you have to continually adjust your mask, it doesn’t fit properly. Try a different mask type or brand.

The CDC has more information about how to wear masks.

Mask fit and filtration

An effective mask has both good fit and good filtration.

Good fit

A well-fitted mask has no gaps between the face and mask, which can allow virus particles to leak in or out.

Good fit forces the air that you breathe out and breathe in to go through the mask and be filtered.

Woman wearing an ill-fitting mask that gaps and lets unfiltered air in and out.
Example of a poorly-fit mask

Good filtration

Good filtration blocks the virus particles from going through the mask itself. You can get good filtration with the right materials and by using more layers. 

Good fit and filtration improve protection for both you and others.

Double masking

“Double masking” is an effective way to improve fit and filtration. A close-fitting cloth mask can be worn on top of a surgical/disposable mask to improve the seal of the mask to the face. 

Layering more than two masks is not recommended as this could be difficult to breathe through. It is also not recommended to wear two medical masks, or to wear a medical mask on top of a KN95 or an N95. 

Double masking may be appropriate where improved fit and filtration are especially important.

When fit and filtration is especially important

Some situations require the higher level of protection you can get from good mask fit and filtration: 

  • Indoor spaces with people from outside your household
  • Close quarters with other people where social distancing is not possible (examples: riding a crowded bus, waiting in line at a crowded airport terminal)
  • Any public place if you are older or have medical conditions that put you at higher risk of severe COVID illness

Even when you’re at home, there are times when a higher level of protection is important, such as when:

  • Caring for family members who are sick or may have been exposed to someone with COVID-19
  • Living in a household with someone who has or may have COVID-19
  • Someone from outside your household comes into your home (like a friend, relative, or repair person)
  • You work outside the home and live with someone who is older or has a medical condition that puts them at higher risk of severe COVID illness.

Read CDPH’s webpage, Get the Most Out of Masking.

Use masks even after you are vaccinated

The CDC recommends wearing a mask even after receiving the COVID-19 vaccine to protect yourself and others. Experts are studying whether getting the vaccine will prevent you from spreading the virus to other people, even if you don’t get sick yourself. It’s important for everyone to continue using all the tools available to help stop this pandemic as we learn more about how COVID-19 vaccines work in real-world conditions.

Mask wearing exceptions

Individuals are excepted from wearing a mask when:

  • In a car alone or solely with members of their own household.
  • Working in an office or in a room alone.
  • Actively eating or drinking. You should maintain a distance of at least six feet from those not in your household.
  • Outdoors and maintaining at least 6 feet of social distance from others not in their household. You must have a face covering with you at all times and must put it on if you are within 6 feet of others who are not in your household.
  • Getting a service to the nose or face for which temporary removal of the mask is necessary.
  • Your job requires you to wear respiratory protection.
  • You are specifically exempted from wearing face coverings by industry specific guidance.

Some people are exempt from wearing face coverings at all times:

  • Children younger than two years old, because they risk suffocation.
  • Those with a medical condition, mental health condition, or disability that prevents wearing a face covering. This includes:
    • Rare medical conditions for whom wearing a face covering could obstruct breathing.
    • Being unconscious, incapacitated, or otherwise unable to remove a face covering without assistance.
  • Those who are hearing impaired, or communicating with a person who is hearing impaired. In these cases, the ability to see the mouth is essential for communication.
  • Those for whom wearing a face covering would create a risk to the person related to their work.

Read the official mask guidance from the California Department of Public Health.

Questions and answers

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