Mask Effectiveness and Purpose By Type

July 30, 2020 Nicki Murff Goedecke

Although there has been a renewed public interest in mask-wearing for infection control due to the rise of COVID-19, it is nothing new for healthcare providers. Nurses, EMTs, doctors, and other healthcare workers have long taken precautions against spreading infectious diseases and viruses using infection control procedures like proper hand washing and personal protection equipment (PPE).

However, in the midst of the coronavirus pandemic, everyone from preschoolers to hair stylists to long-term care nurses are dealing with the reality of mask-wearing for the majority of their day. Though healthcare professionals rarely need to be convinced of the efficacy of wearing a mask to prevent and slow the spread of COVID-19, it’s still worth looking into why masks are effective, how they work, and what the different kinds of face masks should be used for.

History of Masks

Though there are some historical records of masks being worn by medical practitioners as early as the 17th century, mask-wearing really emerged in the late 1800s as a way to prevent the spread of germs from surgeons to patients during operations. During the Manchurian plague of 1910-11 and the influenza pandemic of 1918-19, however, mask wearing outside of the operating theatre began to be more commonplace among healthcare providers and patients, and among the general public.

While not every type of mask is confirmed to prevent the spread of COVID-19, the Centers for Disease Control and Prevention (CDC) does recommend face coverings as a method in combination with other preventive measures to slow the spread of the virus.

Mask Breakdown: Types of Face Coverings and Their Purposes

Cloth Masks:

Traps and protects against airborne droplets released from sneezes, coughs, and exhalations.
Often used by the public in non-healthcare settings to help prevent the spread of viruses, especially in the case of coronavirus, in which the wearer can be infected and not present symptoms.
Washable and reusable.
May be homemade by members of the public, leading to increased availability.
CDC maintains, “a cloth face covering may not protect the wearer, but it may keep the wearer from spreading the virus to others.”

The CDC suggests the following in relation to face masks:

The spread of COVID-19 can be reduced when cloth face coverings are used along with other preventive measures, including social distancing, frequent handwashing, and cleaning and disinfecting frequently touched surfaces.

Surgical Masks:

Protect against airborne droplets of water, such as saliva or secretions from the upper respiratory tract.
Can filter out large particles.
Not officially approved to prevent coronavirus, but may cause protection when respirator masks are unavailable.
Disposable.
Suggested wear-time is three to eight hours.

Respirator Masks (such as N95 masks):

Protects the wearer from airborne infectious agents (including coronavirus) as well as airborne droplets.
Can filter out both large and small particles when the wearer inhales.
May be either disposable or reusable.

See-Through Masks

Typically a cloth mask.
Includes an anti-fog window for lip reading and other non-verbal communications.
Washable and reusable.

Face Shield

Though not technically a mask, face shields are still being used in some settings to protect the wearer.

Should extend around the sides of the face and below the chin.
Only protects wearer from spray, splatter, and droplets. Does not protect against airborne infectious agents.
May be either disposable or reusable. If reusable, must be disinfected after each use. An alcohol-based wipe is sufficient to disinfect the shield.

“It is not known if face shields provide any benefit as source control to protect others from the spray of respiratory particles. CDC does not recommend use of face shields for normal everyday activities or as a substitute for cloth face coverings. Some people may choose to use a face shield when sustained close contact with other people is expected.” - CDC

Mask Hygiene and Use

Before putting a mask on, wearers should be sure to wash their hands. To properly don and doff a mask, users need to be sure not to touch the front of the mask. If the front of the mask is touched when removing it, users should wash hands immediately.

Masks and face coverings that are reusable should be washed or disinfected as often as needed. Mask can be stored in plastic or paper bags. In settings where many people need access to PPE, a dispensing unit may be appropriate to use.

Wearing a mask is a safe and effective way to slow the spread of germs and viruses. Face coverings in public, physical distancing, and good hand washing habits will keep everyone healthy as a vaccine is developed for COVID-19.

CDC safety reminders