All Californians should continue using available tools, including masks, to help mitigate the spread of COVID-19 and other respiratory infections in their community. Wearing a mask consistently and correctly is one of the best ways to protect yourself from getting COVID-19 or other respiratory infections.

Masks remain a critical component for protecting the most vulnerable people in our communities, including older adults, people who are immunocompromised, have certain disabilities or underlying health conditions, and are otherwise at increased risk of getting severe COVID-19 and other respiratory infections. 

Masks vs. R​​espirators

Throughout this and other guidance, the term “mask" is used to refer to both loosely fitting cloth and surgical masks and tightly fitting respirators.

Respirators are a specific category of masks that are designed so that every time users breathe in or out, each breath is filtered through the material. Respirators provide the best protection against airborne diseases, including COVID-19. 

When Masks Should be Worn

The California Department of Public Health (CDPH) recommends all Californians wear a mask:​

• Around others if you have respiratory symptoms (e.g., cough, runny nose, and/or sore throat),
• If you've had a significant exposure to someone who has tested positive for COVID-19, wear a mask for 10 days.  
  
• ​If you test postive for COVID-19, see guidance for mask wearing in the CDPH Guidance for Isolation and Quarantine of the General Public​. 
  

​In addition, wearing a mask is increasingly important for those who are at higher risk for getting very sick from COVID-19, and as the risk for transmission increases in the community. Examples of settings where it may be important to wear a mask:

• ​In indoor public settings where people who are older or have medical conditions that put them at higher risk of severe illness may reside or are cared for (such as hospitals, skilled nursing facilities, and long term-care facilities).
• In crowded indoor public settings that may have poor ventilation, including public transportation and other congregate settings. 
  
• See additional information on how to assess your risk in indoor public settings and exposure risks.  
  

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

• You are providing care for someone who is sick with or who may have been exposed to someone with COVID-19 or another respiratory infection.
• You live in a household with someone who is suspected of having or has COVID-19 or another respiratory infection.​
  

Local health jurisdictions and other entities may continue to have requirements in specific settings based on local circumstances, including in certain higher-risk settings or during certain situations that may necessitate mask requirements (for example, during active outbreaks in high-risk settings).

​Furthermore, no person can be prevented from wearing a mask as a condition of participation in an activity or entry into ​​a venue or business (including schools or childcare) unless wearing a mask would pose a safety hazard. ​

Poor Fitting Face Covering 

Medical Masks (also called Surgical Masks or Disposable Face Masks)

Medical masks include various types of loose-fitting disposable masks. These masks are designed to block large droplets and are not designed to fit closely to the face or to filter aerosols that can transmit COVID-19 or other respiratory viruses. Even when adjusted to fit tightly against your face, medical masks are much less effective for protection than a well-fitting respirator (N95, KN95, or KF94). ​

Cloth Masks

Cloth masks are less effective than either surgical masks or high-quality respirators and are no longer recommended. Individuals should not rely on cloth masks* for protection from COVID-19 or other respiratory infections. A mask that does not create a tight seal against your face does not provide the best protection against getting sick. ​

Masks for Children

Just as with adults, the protection that children get from masks depends on finding a mask with good filtration, good fit, and that can be worn consistently.

KN95s and KF94s are both available in "child" or "extra-small" sizes and may be the best choice for younger children. N95s in size “small" may fit older children but may not fit younger, smaller children well.

Children younger than two years of age must not wear a mask due to the risk of suffocation.

*Cloth masks that meet the ASTM F3502-21 Standard Specification for Barrier Face Coverings are likely to provide better fit and filtration than cloth masks that don't, especially if they have a high particulate filtration efficiency and high leakage ratio. ​​​

Resources

• CDC Improve How Your Mask Protects You
• CDC Science Brief: Community Use of Masks to Control the Spread of SARS-CoV-2
• CDC List of ASTM-3502-21 Conforming Face Coverings
• NIOSH Testing of International Respirators
• NIOSH-Approved Particulate Filtering Facepiece Respirators
• CDC Required Labeling of NIOSH-Approved N95 Filtering Facepiece Respirators
• NIOSH How to Conduct an N95 Seal Check
• N95 Mask Size Guide
• AHRQ: Respirator fit testing 
• CDC How to tell if your N95 Respirator is NIOSH Approved
• CDPH Get the Facts on COVID-19 Treatments
• CDC Understanding Exposure Risks​

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Originally Published on March 4, 2021