What Does the N95 Stand for in N95 Masks?

Updated: Mar. 16, 2023

Who knew?

A global pandemic

As COVID-19 spreads around the world and cases continue to increase, there are multiple aspects of the worldwide pandemic to pay attention to. From knowing the difference between an epidemic and a pandemic, the signs and symptoms of COVID-19, and what hospital workers need in order to help save patients, there are a lot of new terms to learn. When the coronavirus was at its worst, you probably heard that hospitals needed more ventilators, N95 respirators, and surgical masks, but what does N95 stand for? These are the shortages we’re likely to see in winter because of COVID-19.

What’s an N95 respirator?

First of all, it’s important to note what these masks are. According to the Food and Drug Administration, an N95 respirator is “a respiratory protective device designed to achieve a very close facial fit and very efficient filtration of airborne particles.” A surgical N95 respirator, according to the Centers for Disease Control and Prevention (CDC), “is a NIOSH-approved N95 respirator that has also been cleared by the Food and Drug Administration (FDA) as a surgical mask.”

What does N95 stand for?

According to the National Institute for Occupational Safety and Health (NIOSH), there are different types of disposable particle respirators and an N95 respirator falls into that category. But what is a disposable particle respirator? According to the CDC, “Particulate respirators are also known as ‘air-purifying respirators’ because they protect by filtering particles out of the air as you breathe. These respirators protect only against particles—not gases or vapors. Since airborne biological agents such as bacteria or viruses are particles, they can be filtered by particulate respirators.”

There are two separate factors in classifying a disposable particle respirator: how the mask filters air and how resistant the mask is to oil. The different ratings in place for respirators indicate how well the mask would protect against oils and are rated as N, R, or P. According to NIOSH, “respirators are rated ‘N,’ if they are Not resistant to oil, ‘R’ if somewhat Resistant to oil, and ‘P’ if strongly resistant (oil Proof).”

This is where the numbers come in. Respirators that filter out 95 percent of airborne particles are given a 95 rating, so N95 respirator filters out 95 percent of airborne particles but is not resistant to oil. The respirators that filter out at least 99 percent of airborne particles have a 99 rating and the ones that filter out 99.97 percent of airborne particles, which NIOSH notes as essentially 100 percent, receive a 100 rating. This is how to stock up, emergency or not.

The similarities and differences between N95 masks and surgeon masks

The CDC has an infographic highlighting the differences between surgical masks and N95 respirators. For example, testing and approval for surgical masks are done by the FDA, whereas testing and approval for N95 respirators are done by NIOSH. Surgical masks are loose-fitting whereas N95 respirators have a tighter fit. For similarities, according to the FDA, both masks are “tested for fluid resistance, filtration efficiency (particulate filtration efficiency and bacterial filtration efficiency), flammability and biocompatibility.” Surgeon masks and N95 masks should not be reused or shared. These uplifting stories of neighbors helping during coronavirus will inspire you to do the same.


  • FDA: “N95 Respirators, Surgical Masks, and Face Masks”
  • CDC: “Respirator Trusted-Source Information”
  • CDC: “Understanding Respiratory Protection Against SARS”
  • CDC: “Understanding the Difference: Surgical Mask and N95 Respirator”
  • World Health Organization: “Coronavirus disease (COVID-19) advice for the public: When and how to use masks”