With COVID-19 transforming daily life for billions of people across the planet, new words and phrases are entering everyday vernacular. A year ago, terms like Personal Protective Equipment (PPE), social distancing, and medical masks were reserved for medical or technical environments. Now, they are all commonplace in daily conversation. Despite their increased use in recent months, many people are still confused or uninformed about them. For example, medical mask is a relatively broad term that could actually refer to a wide range of devices. 

To help you better understand the concept of a medical mask, we offer this guide to define the term, provide examples, and show how you can obtain a medical mask to help stem the spread of COVID-19.

How a Medical Mask is Regulated

As previously mentioned, “medical mask” is a rather broad term. There are dozens, if not hundreds of different kinds of medical masks. However, generally speaking, a medical mask refers to a face mask that is (or can be) used in a medical environment. Additionally, a medical-grade mask meets certain standards established by regulatory agencies like the National Institute for Occupational Saftey and Health (NIOSH) and the Food and Drug Administration (FDA). 

Thus, a medical mask is more than just a face covering. It is a medical-grade mask that is specifically designed and tested to prevent the inhalation of airborne bacteria and protect the wearer from fluid splatter. To ensure the quality of a medical mask, the regulatory agencies listed above use various tests, techniques, and legal mandates. In order to legally produce and distribute medical masks, PPE manufacturers must meet these standards. So, let’s take a closer look at the standards for producing a medical mask: 

  • Fluid resistance - This refers to a mask or material’s ability to repel or absorb fluids.
  • Filtration efficiency (particulate and bacterial) - This refers to a mask or material’s ability to filter out particles of varying sizes, as well as airborne bacteria.
  • Flammability - This refers to a mask or material’s ability to resist flames.
  • Biocompatibility - This refers to a mask or material’s level of toxicity (or propensity to cause injury).

However, these are just the general categories used to test a medical mask. Different types of medical masks must be able to perform better in certain areas than others. For example, a medical mask used to prevent fluid splatter during surgery will differ from a medical mask used to prevent particulate infiltration in a high-risk environment. 

Before we look at the different kinds of medical masks, let’s first examine what does and does not qualify as a medical mask.

What Does Not Qualify as a Medical Mask?

There are various safety masks and face coverings that are used in place of medical masks but do not meet the standards to be used in a medical environment. Some of these include:

Cloth Masks

Cloth masks are one of the most popular options available, as they are comfortable, reusable, and customizable. They are also readily available to purchase from most major retailers, both in-person and online. If you want to stick to a budget, you can even make your own cloth mask at home. For those who want to make their own, we recommend using the Center for Disease Control and Prevention (CDC) guidelines.

While cloth masks are affordable, comfortable, and in-stock around the country, they are not the safest option. Cloth masks tend to be more porous than polypropylene fiber (the material used for most medical-grade masks). As a result, cloth masks can let in both large and small particles. However, the efficacy of a cloth mask will depend on a variety of factors, including the number of layers, how it is used, and how often it is washed. According to the World Health Organization (WHO), cloth mask efficacy can range anywhere from 1%-70%, depending on the factors previously mentioned.   

Face Coverings

In addition to traditional cloth masks, there are a number of non-mask alternatives. Many people use scarves, neck gaiters, balaclavas, and other cloth coverings to protect their mouth and nose. Needless to say, these do not qualify as medical-grade masks. In fact, they are far less effective than standard cloth masks. A study from Duke University even showed that these solutions can, in some circumstances, increase the risk of spreading COVID-19.

Alternative face coverings are ineffective because they were never designed to filter out particles or repel fluid in the first place. They are merely garments that some people use out of convenience when masks are not easily accessible. As a result, many cloth coverings are loosely-woven, leaving open pockets for particles to enter. To make matters worse, they do not have any kind of filtration systems like medical-grade masks and even some cloth masks.

Face Shields

Face shields are often used in conjunction with some form of face mask. Though face shields are effective against fluid splatter (to a degree), they provide absolutely no particle filtration. This means that particles of any size can reach your mouth and nose from underneath the shield. Thus, face shields should only be used as an added layer of protection. In fact, the CDC has stated that, as long as you wear some kind of face mask, a face shield is largely unnecessary. 

While face shields are frequently used by healthcare workers, a face shield does not qualify as a medical mask. This is due to the fact that a shield is not a “mask” insofar as it does not cover the face tightly. Instead, a face shield usually rests approximately one to two inches away from the face, leaving ample room for particles to enter from the sides or underneath. So, without some form of medical mask, face shields do not qualify as medical-grade PPE. 

What Qualifies as a Medical Mask?

Now that we’ve covered what doesn’t qualify as a medical mask, it’s time to look at the different kinds of masks that are regulated and designed to be used in a medical environment. Surprisingly, this can get a little tricky, as there are specific masks designed for specific medical procedures, environments, and situations. In any case, there are two basic categories of medical masks: surgical masks and respirators.

Surgical Mask

Despite the name, surgical masks are not always meant for surgery. In fact, the term refers to any medically-regulated mask that covers the nose and mouth and does not qualify as a respirator. Generally, surgical masks are green or blue, with straps that fit around each ear. These masks are disposable and meant to be worn for relatively short periods of time. 

However, surgical masks can vary significantly based on a variety of factors. For example, dentists frequently use the standard flat, rectangular surgical mask that provides ample protection from fluid splatter and moderate-to-high protection from airborne particles. However, a doctor or healthcare worker in a high-risk environment might prefer a cone-shaped, densely woven mask with a metal nose clip. These generally provide greater protection from fluid splatter and higher particulate filtration.

That said, it’s extremely important to note that surgical masks do not provide high-level protection from particles. Surgical masks are most distinctive from respirators and higher-level medical masks (see below) by their loose-fitting design. They are easy to take on and off, provide moderate comfort, greater breathability, and high-level protection against fluid splatter. However, they are not sealed against the face, which means that bacteria and other particles can still reach the mouth or nose by going in through the sides, bottom, or top (even if there is a nose clip present). 

Medical-grade surgical masks can also be differentiated by various levels of efficacy. These levels are determined by the American Society for Testing and Materials (ATSM). There are essentially three types of medical-grade masks based on ASTM standards: Level 1, Level 2, and Level 3. An ASTM Level 1 mask can filter out as much as 95% of bacteria and particles. These are designed for short procedures and are not ideal for protecting against strong aerosols and fluid splatter (like a cough or sneeze directly to the face). 

The next step up in protection is the ASTM Level 2 mask. This type of surgical mask provides as much as 98% filtration for bacteria and particles, while also providing greater protection from airborne liquids. ASTM Level 2 masks are common in many hospitals and medical facilities.

Finally, there is the ASTM Level 3 mask. This is the highest grade surgical mask (short of a respirator) for filtration. However, it is not a huge step up from the Level 2 mask. It also provides up to 98% filtration and significant protection against fluid splatter. However, it is the highest graded surgical mask and is therefore the first choice of mask for most healthcare workers who cannot access respirators.

N95 Medical Mask and Above

While surgical masks are more commonly used in low-risk environments (or when better PPE is not available), N95 masks (also known as respirators) are the standard, high-level form of medical masks. As the name suggests, N95 masks filter out 95% of airborne particles. Additionally, they seal against the face, preventing airborne particles from getting in through gaps around the mask. Finally, N95 masks can come with various extra features, including nose clips and airflow vents.

To have a better understanding of its unique qualities, you can see the FDA’s definition of the N95 medical respirator below:

“An N95 respirator is a respiratory protective device designed to achieve a very close facial fit and very efficient filtration of airborne particles. Note that the edges of the respirator are designed to form a seal around the nose and mouth. Surgical N95 Respirators are commonly used in healthcare settings and are a subset of N95 Filtering Facepiece Respirators (FFRs), often referred to as N95s.”

However, the N95 medical mask is not the only medical-grade respirator. There are also the N98, N99, and N100 masks. Needless to say, each of these can provide additional filtration, up to 99.9%. 

In addition to the differences outlined above, there are also differences in the ways that surgical masks and respirators are regulated. Both are regulated by the FDA, but surgical masks generally meet standards set by ASTM (as outlined above), while respirators like the N95 must meet standards set by NIOSH. More specifically, the N95 and higher-level respirators must meet the following standards:

“Masks intended for respirator precertification may require NaCl, DOP, valve leak, and inhalation/exhalation tests to verify conformity to NIOSH standards. Nelson Labs offers precertification testing services for these tests.

The Sodium Chloride Aerosol Challenge (NaCl) – NIOSH Respirator Prequalification test uses a widely accepted method for evaluating particle penetration and air flow resistance properties of a variety of filtration materials. Respirators must be prequalified before submitting to NIOSH for certification; other materials, such as breathing system filters and face masks, are tested to determine filtration efficiency for marketing. These tests are performed for masks seeking N95 respirator precertification.

The Dioctyl Phthalate (DOP) test is used to evaluate particle penetration and air flow resistance properties for a variety of filtration materials, including HEPA filters, NIOSH respirators, and filter media. The test is performed in compliance with 42 CFR Part 84 and NIOSH Procedure No. RCT-APR-STP-0051-0056, 2005 and is necessary for prequalification for NIOSH certification of respirators. Nelson Labs has extensive experience testing filters and other filtration devices.

Testing is performed in compliance with 42 CFR Part 84 and NIOSH Procedure No. RC-APR-STP-0057, 0058 and 0059. Nelson Labs has extensive experience testing filters and other filtration devices.”

Thus, the N95 mask — as well as the N98, N99, and N100 — are some of the safest and most regulated medical masks on the market. Every N95 medical mask must go through dozens of tests before it can reach the market. As a result, these kinds of respirators are the best medical masks available to healthcare workers and consumers.


In closing, there are essentially two forms of medical mask: surgical masks and respirators. However, even within these two categories, there are more specific kinds with additional features and protections. In any case, it’s important to note that there’s no such thing as a reusable medical face mask. All medical-grade masks are meant for single-use only. 

For more information on both non-medical and medical mask safety, be sure to consult the Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO).