Dust Masks and COVID-19

As the Coronavirus continues to propagate through the country and into our communities, many people are leaning on self-proclaimed “experts” to determine the best course of action to protect themselves. The product which is most sought after, other than toilet paper and hand sanitizer, is the “dust mask” or “facemask.” This term is used interchangeably for a paper-like mask that covers your face. It is believed that a dust mask protects you from dust and other airborne contaminants. This term makes its way into the vernacular of seasoned health and safety professionals, as well as highly educated medical professionals. The problem is when it is used so interchangeably, it spreads misinformation that may confuse the public and cause a dangerous and false sense of security. People hear terms like N95, N100, P99, surgical mask and on. What do those terms mean? How do you know if it is actually protecting you?

First, it is important to note that according to current guidance from the Centers for Disease Control and Prevention (CDC), facemasks are only to be used if you are sick and you will be around other people or if you are caring for a sick person who is not able to wear a facemask. In this case, “facemask” means a surgical mask. A surgical mask is a covering for your nose and mouth which will stop or slow aerosolized saliva created when you breathe, sneeze, or cough. It helps reduce airborne viruses, thus the likelihood of spreading the virus. It will do very little to prevent contracting the virus. It is only indicated for protection against large droplets, splashes, or sprays of hazardous fluids. A surgical mask does not seal tightly against your face, so air will very likely flow around the mask and into the upper respiratory tract (URT). A virus can be between 0.004 to 0.1 microns in size. It can and will flow through and around products that are not designed to filter them out of the air you breathe. It is important to note that a surgical mask is not an approved respirator according to the National Institute for Occupational Safety and Health (NIOSH), a division of the CDC. Wait…what?!?

What is a respirator and when should you use one?

According to NIOSH, a respirator is: “a personal protective device that is worn on the face or head and covers at least the nose and mouth. A respirator is used to reduce the wearer’s risk of inhaling hazardous airborne particles (including infectious agents), gases or vapors. Respirators, including those intended for use in healthcare settings, are certified by the CDC/NIOSH.”

NIOSH approved dust mask

Respirators are worn to protect people from a known airborne hazard. Respirators undergo rigorous testing, approval, and certification process administered by NIOSH to ensure they meet the requirements of the Occupational Safety and Health Act of 1970 (OSHA) Respiratory Protection Standard. NIOSH publishes a Certified Equipment List (CEL) of all approved respirators. If a “dust mask” does not contain a NIOSH approval number on the box/label and the mask itself, it is not approved to be used as a respirator and cannot be guaranteed to filter contaminants from the air you breathe.

Side by side comparison of NIOSH approved and not approved dust masks

A “dust mask” which is a NIOSH approved respirator is also called a filtering facepiece respirator (FFR). All FFRs are given efficiency ratings such as N95 or P100. Let’s break these down into their individual components. The leading letters are defined as follows:

  • N = Not resistant to oil
  • R = Somewhat resistant to oil
  • P = Strongly resistant to oil

The numbers in the designation are defined as follows:

  • 95 = Filters at least 95% of airborne particles
  • 99 = Filters at least 99% of airborne particles
  • 100 = Filters at least 99.97% of airborne particles

“A respirator is a personal protective device that is worn on the face or head and covers at least the nose and mouth. A respirator is used to reduce the wearer’s risk of inhaling hazardous airborne particles (including infectious agents), gases or vapors. Respirators, including those intended for use in healthcare settings, are certified by the CDC/NIOSH.”

So, you’ve found a NIOSH approved N95 FFR. Congratulations, you’re one of the lucky few. Just because you are wearing a respirator, it doesn’t mean you are automatically protected. There are several factors that can contribute to rendering your new respirator virtually useless. Here are questions you need to, not only ask yourself, but know how to answer them:

  • Does it fit?
  • Is it damaged?
  • Is it contaminated?
  • How should I dispose of it?
  • Can my heart and lungs handle wearing it?

Does It Fit?

When wearing a respirator in a workplace situation where it is required, a fit test must be performed. In this case, it isn’t (or maybe, check with your supervisor if it is) required by your employer, so how do you know if it fits? First of all, you cannot have any facial hair that interferes with the seal. NIOSH has released an info-graphic entitled Facial Hairstyles and Filtering Facepiece Respirators which provides a pictorial reference of what types of facial hair are allowed while wearing an N95 FFR.

You also need to perform a user seal check. With an FFR, a user seal check can be very difficult and will vary by make and model. For exact instructions, check the package your N95 came in. Generally, a positive user seal check is the only way to conduct this test. You should cover as much of the respirator as you can with your hands without collapsing the respirator or pushing it against your face. Exhale gently into the facepiece. A slight positive pressure should build up in the respirator and is evidence it is fitting you properly. If you feel air rushing in around your nose or chin, it doesn’t fit properly and requires adjustment. I can’t stress enough that this is a critical step to avoid a false sense of security. If it does not fit, you may contaminate the inside of your N95, defeating the purpose of wearing it in the first place.

Is It Damaged?

Every time you put a respirator on, you should check it for damage. Check for the following:

  • Rips/Holes in the filter
  • Worn elastic on the head and neck bands
  • Head/Neck bands that have become detached from the facepiece
  • Missing/Torn exhalation valve (if applicable)

Any damaged respirator should be disposed of immediately and not be used. I often recommend destroying it further so it cannot be used instead of just throwing it on top of the trash where someone can easily remove it and use it. You would be surprised what a desperate person may do during a pandemic.

Is It Contaminated?

A contaminated respirator is a dangerous respirator. If you wear your respirator around a person known to have been exposed to the SARS-CoV-2 virus and is showing signs of having contracted COVID-19, your respirator is now likely contaminated. Worse yet, if it doesn’t fit (see above), the inside may be contaminated. When you are protecting yourself from a contaminant that is invisible to the naked eye, like a virus, it is best to dispose of your mask as soon as you leave a known contaminated area and wash your hands for at least 20 seconds and then wash your face. This article does not address other protective clothing and other types of contamination. See the CDC website for more information on how to protect yourself from contracting COVID-19.

How Should I Dispose of It?

When you’re done with your N95 respirator, proper disposal is important. Never leave a used respirator laying around or directly on top of the trash bin. If possible, destroy the respirator prior to disposal and always remember to wash your hands and avoid touching your face before doing so.

Can My Heart and Lungs Handle Wearing It?

In an industrial environment, a FFR does not always require medical clearance prior to wearing one. However, in the public, people with far more advanced underlying conditions may consider wearing a FFR to protect themselves. A FFR will put strain on your body. It requires additional breathing capacity to inhale the same amount of air needed to oxygenate your blood through a filter that removes at least 95% of particulates in that air. Additionally, wearing a FFR when you are sick with a pulmonary disease, further straining your respiratory system could cause excessive stress on your heart and lungs. Finally, add any potential physical exertion and your heart and lungs may suddenly be working several orders of magnitude harder than normal. Check with your doctor if you have any conditions that may be exacerbated by wearing a FFR before you use one.

As you can see, there are a lot of considerations for using an N95 respirator. Since the CDC is recommending the general public NOT to use them, I would prefer my friends, family, and colleagues follow that recommendation. Most of all, please do not use any “homemade” masks. No man-made fabric will provide the level of protection you need and there is no way they will meet the rigorous NIOSH requirements to be approved as a respirator or surgical mask.


Please consider all of the potential implications of hoarding and using masks for which you are not properly trained to use. Healthcare professionals are trained to ensure these masks are not only put to good use caring for your family and friends, but are used properly to prevent the spreading of disease or further damaging their own health. Definitely don’t use ANY homemade mask that someone you know made out of craft fabric, yarn, or any other man-made fabric which is not designed to keep saliva particles out or in. You may get some protection from using the wrong face mask, but odds are high that you will be doing far more harm than good. Finally, if you witness this misinformation on social media, in public or within your own circle of family and friends; please help set the record straight so we can all help stop the spread of this deadly disease.

Apex Associated Press (Apex AP) represents contributions from various authors within the Apex professional community.


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