Masks Information

Guidance for the Use of Face Coverings

Note: This guidance takes effect on August 3, 2021, and will supersede all prior face coverings guidance.


The COVID-19 vaccines are effective in preventing infection, disease, and spread. Unvaccinated persons are more likely to get infected and spread the virus which is transmitted through the air and concentrates indoors. The guidance aligns with CDC recommendations and provides information about higher-risk settings where masks are required or recommended to prevent transmission. When people who are not fully vaccinated wear a mask correctly, they protect others as well as themselves. Consistent and correct mask use by people who are not fully vaccinated is especially important indoors.

Mask Guidance for Individuals (regardless of vaccine status)

Effective August 3, 2021 face coverings must be worn over the mouth and nose – regardless of vaccination status – in all indoor public settings, venues, gatherings, and workplaces, including but not limited to: campus buildings, retail stores, restaurants and bars, theaters, family entertainment centers, conference and event centers, and State and local government offices serving the public.

Individuals are not required to wear face coverings in the following circumstances: 

  • You are not required to wear a face-covering if you are alone in a room with the door closed or when eating or drinking.
  • If you are not fully vaccinated, you should avoid eating indoors in crowded settings, choose outdoor dining options and use to-go options as much as feasible, or when those options are not available, you should maintain 6 feet of physical distance while eating and drinking.
  • Face coverings are not required if you are performing a task that cannot be performed while wearing a face covering.
  • Face coverings do not have to be worn by a residential student while in their own living space (e.g., room, suite, apartment, etc.) regardless of vaccination status.

Please note that individuals with an approved medical or religious exemption are still required to wear a face-covering while indoors.

Exemptions to masks requirements

The following individuals are exempt from wearing masks at all times:

  • Persons younger than two years old. Very young children must not wear a mask because of the risk of suffocation.

  • Persons with a medical condition, mental health condition, or disability that prevents wearing a mask. This includes persons with a medical condition for whom wearing a mask could obstruct breathing or who are unconscious, incapacitated, or otherwise unable to remove a mask without assistance.

  • Persons who are hearing impaired, or communicating with a person who is hearing impaired, where the ability to see the mouth is essential for communication.

  • Persons for whom wearing a mask would create a risk to the person related to their work, as determined by local, state, or federal regulators or workplace safety guidelines.

Mask Types

Here are examples of the various types of masks that are being used to protect public health.  See also CDC Mask Guidance.

N-95 Respirators

About N-95 Respirators

Protect the wearer from breathing in airborne particles like viruses, bacteria, dust, wildfire smoke, and other particulate matter.

Employees with occupational exposures are required to wear these including healthcare workers and lab researchers. Because these masks make it harder to breathe, medical clearance is required for mandatory use, and a fit test is performed to ensure the respirator makes a good seal with the face. Facial hair must not interfere with the seal of the mask.

Voluntary use of N95s allows use without medical clearance and fit testing.  N95s are disposable and not intended for reuse in most cases.

Please do not buy or stock up on N-95s or surgical masks.

Please do not buy or stock up on surgical masks or N-95s. Preserve the limited supply of medical-grade masks such as an N-95 for health care workers or first-responders, who cannot use physical distance to protect themselves, especially from people at their most symptomatic, infectious period.  The City of Berkeley is collecting PPE donations through their website. All these donations will be vetted/ distributed to healthcare facilities, EMS partners, and Skilled Nursing Facilities/Long-term Care Facilities depending on need.

Cloth Masks

About Cloth Masks

These masks are sewn from cotton fabrics and constructed to look like a surgical mask, sometimes with a pleated panel. They function like a surgical mask, so long as the fabric weave is thick enough to prevent droplet penetration when coughing and sneezing.  Cloth masks should be washed before reuse.

A cloth face covering is a material that covers the nose and mouth. It can be secured to the head with ties or straps or simply wrapped around the lower face. It can be made of a variety of materials, such as cotton, silk, or linen. A cloth face covering may be factory-made or sewn by hand or can be improvised from household items such as scarfs, T-shirts, sweatshirts, or towels. Make sure the covering is comfortable – you don’t want to have to keep adjusting the mask, which means touching your face.  Always wash your hands, or use hand sanitizer, before and after touching your face or face coverings.

How to Properly Wear and Care for Your Cloth Face Covering

From UC Berkeley EH&S: Video - How to Properly Wear and Care for Your Cloth Face Covering

Dust Masks

About Dust Masks

These look like N95 respirators but they may not have the proper certifications that N95s have (e.g. NIOSH certification). 

Dust masks are okay for voluntary use. They are typically sold in hardware stores for people who need protection from sawdust and other construction work.  Dust masks are disposable.

Neoprene Masks

About Neoprene Masks

These masks are typically designed for sports use where wind and thermal protection is desired.  Because the material is thick, it can prevent the spread of droplets from the mouth and nose, depending on mask design.  Neoprene fabrics are washable and reusable. Masks should be washed before reuse.

KN95 Masks

About KN95 Masks

Equivalent to N95 respirators, but are not cleared by the FDA and typically used in China.  With worldwide supply shortages of N95s in America, more KN95 masks are starting to appear in this country.

Surgical Masks

About Surgical Masks

These masks are not considered respirators; they do not filter out particles to the extent that N95 and KN95 masks do. Surgical masks contain droplets and spittle from the mouth and nose of the wearer.  Because they do not make a tight seal with the face, particles can enter around the edges of the mask. Surgical masks are disposable and not designed for reuse in most cases.