By: Aditi Vyas, MD, MPH
Medical Director
Department of Employee Health
NorthShore University HealthSystem

Michael Fiore, MPH, CH, contributed to this article.

With masking guidelines evolving and as recommendations change for mask usage, it’s helpful to know what to look for when purchasing a respirator mask to protect against the COVID-19 virus. The most recent Centers for Disease Control and Prevention (CDC) guidelines can be found here.

In general, well-fitting respirators provide better protection than a cloth/surgical mask.

Overall, the best mask for you and your family is one that fits snug around your face and is comfortable to wear. To make sure you are protected and are fully benefiting from the mask, the mask should form a seal around your face.
Make sure to not have any obstructions such as facial hair or other cloth or masks in between your face and respirator.

How to do a seal check: Make sure your respirator is snug, put your hands around the mask and blow air out. If you have a good seal, you should NOT feel air coming out of your mask.

Information and visuals: 3M Science. Applied to Life.

Respiratory masks also attach to the head differently with straps than a generic mask, which has loops. This may also play a role in comfort level. Almost all N95 masks have two straps, which will likely be two elastic bands that wrap around the head. A Mask that with ear loops and claims to be an N95 is likely not authentic.

Below you will find a guide to the three most common types of masks available to purchase on e-commerce platforms.

• What does N95, KN95, and KF94 mean
• How to tell if they are authentic
• If they are NIOSH approved

Types of respirator masks available to the public: N95, KN95, and KF94.

N95 masks
Respirator masks are made in the United States. These are heavily regulated and are used by healthcare workers. Regulated by a division of the CDC called NIOSH.

What does N95 stand for:

• N: means non-oil. If no oil-based particulates are present, you are able to use this mask in the environment.
• 95: 95% of non-oil-based very small particles will be filtered out including bacteria, virus, and very small dust particles.

Who approves and certifies N95 masks in the United States:
NIOSH: National Institute for Occupational Safety and Health

• NIOSH-approved masks remove particles from the air as you breathe through it. Respirator masks have to pass strict quality assurance and performance requirements.
• All NIOSH-approved respirators have a testing and certification (TC) approval number. You can search Certified Equipment List (CEL) here to see if your mask is approved by NIOSH.

KN95 masks
Given the shortage of masks, these types of masks are readily available to the public.

• Most are made in China. Regulated by the Chinese government.
• Many readily available KN95 masks are NOT regulated in the United States and do not filter what they claim.
• Roughly 60% of KN95s are not authentic and do not meet NIOSH standards, according to the CDC.
• Look for trusted and credible vendors when purchasing.
• These usually have ear loops and are more comfortable than N95 masks with straps.
• Make sure your seal is good. Use the seal check method described above.
• NIOSH APPROVED: NO

KF94 masks
Also readily available to the public.

• Most are made in Korea.
• If authentic, they are high-quality masks that are highly regulated.
• In Korea, these respirators are strictly regulated.
• Look for Korean vendors that are credible.
• Fold-flat and have ear loops leading to more comfort compared to N95 masks.
• KF: stands for Korean Filter
• 94: means these filter 94% of the airborne particles
• Make sure your seal is good. Use the seal check method described above.
• NIOSH APPROVED: NO