Can I Reuse My N-95 Masks?


This paper is the fourth in a series on the pandemic disease, COVID-19. The first paper focused on safely reopening your business.  The second one concerned face masks, the primary PPE (personal protective equipment). The third paper involved examining the exposure routes. Finally, this one will discuss the reuse of N-95 masks. This has been of great importance during the current pandemic.  That is due to shortages of N-95s and the need to protect everybody.  Further, health care workers and other front line workers must be protected from infected and asymptomatic carriers of the SARS-CoV-2 novel corona virus.

N-95 Masks Not Designed for Reuse

Do not reuse N-95s. Wear them one time and throw them away. Their paper cloth-like material does not stand up well when washed or disinfected. The filtration can be reduced and put the wearer at risk. The elastic bands and the filter material may become distorted.  Then the mask does not seal properly to the face or fit properly. This allows air leakage and defeats the purpose. Also, viruses, bacteria, and physical particles can become trapped on the outside of the filter material and lead to infection when touched.

Short Supply has Forced the Issue

Necessity is the mother of invention! And because the N-95 has come into such demand, we have been forced to explore reuse of these disposable masks. The scientists and regulatory agencies have explored various options and made emergency concessions for the reuse of N-95s. Federal agencies involved include the Center for Disease Control (CDC,, Occupational Safety & Health Administration (OSHA,, and the Food and Drug Administration (FDA,

N-95 Masks Reuse Guidelines

The simplest method is to store the N-95 in a closed paper bag and not reuse it until 5 days later. This is not true disinfection but it banks on the virus dying outside of the body, which is typical of most micro-organisms. The CDC identifies the following disinfection methods:

  • Moist Heat (think autoclave)
  • Ultra-violet Light
  • Hydrogen Peroxide

Only trained scientists and medical personnel can use these disinfection procedures. Examine the masks for distortion and damage, then fit test them on personnel.  Just remember – when in doubt, throw it out!

As the Virus Turns

That sums up reuse and disinfection at this time. But stay tuned, because new information and data come in every day!

Environmental Safety ConsultantsSo there is a discussion of reusing N-95s. If you need any assistance, ESC ( is here. We have a board Certified Industrial Hygienist (CIH) on staff and have been providing respiratory protection services to our clients for thirty years. ESC has the credentials and experience to help you with your respiratory protection needs. We are just a telephone call (800-226-1735) or an e-mail away ( Contact us today!

Face Masks and COVID-19


This paper is the second in a series on the pandemic disease, COVID-19. The first paper focused on safely reopening your business. The current paper will concern the issue of face masks. These face masks are part of PPE or personal protective equipment which has become an everyday term since the pandemic began in this country last year. It is refreshing to be able to discuss PPE without the listener’s eyes glazing over! Of course, PPE can include gloves, suits, hearing protection, face shields, hard hats, steel toed boots, and more, but this paper concerns face masks for respiratory protection. 

Face Masks and COVID-19 Primer 

The face masks used to protect people from breathing in SARS-CoV-2 (the novel corona virus which causes the disease COVID-19) have included surgical masks, N-95 masks, handkerchiefs, face shields, neck gaiters, and more. None of these actually filter out the virus (which is approximately 0.1 micron in diameter), but rather, they filter out respiratory droplets that are expelled when people exhale, talk, sing, laugh, cough, sneeze, etcetera.

Of the masks above, N-95s offer the best protection. To explain, the N stands for non-oil proof, so they do not work in an oily environment – anywhere there is oil in the air, typically as a mist. Next, the 95 means that they filter out 95% of particles 0.3 micron in diameter. Dioctyl phthalate is the chemical used to test the respirators. If they pass the test, the manufacturers can deem them N-95 respirators after meeting other certification requirements of NIOSH (the National Institute of Occupational Safety & Health, which is a part of the CDC, the Center for Disease Control, ( Once they meet the certification requirements, they can display N-95 labels. 

How to Wear the N-95  Face Mask

The N-95 face mask has two straps, a lower, and an upper strap. Firstly, put it on the lower strap by putting it over the head and then lowering it so it rides along the back of the neck. Secondly, put the upper strap over the head and rest it on the crown in the back.  Thirdly, seal the face piece snugly over the nose, down the face, around the mouth, and beneath the chin. Finally, bend the part that goes over the nose so it fits closely over the bridge and down the sides. By following these steps, the N-95 will be sealed to the face so no air comes through cracks, which means the mask filters the air inhaled and exhaled. Which brings up a point that exhalation valves do not filter exhaled air. People can inhale the germs, so exhalation valves are not recommended.

What if you Can’t Get an N-95 Face Mask for COVID-19 Protection? 

If you cannot get an N-95 face mask for COVID-19 protection, use a surgical mask. If one is not available, use a cloth filtering mask. The other types of masks are on down the list. 

How often Can I Wear the Face Mask? 

The face mask is not designed to be worn over and over. Throw it away after each use or disinfect it if possible. As with everything else, consult the manufacturer. 

Tell Me More about Inhalation Exposure from the COVID-19 Virus

Inhalation exposure from the COVID-19 virus is the topic of our next paper. We will discuss airborne exposure of the virus itself and exposure to respiratory droplets. Stay tuned! Environmental Safety Consultants

So there is a discussion of face masks and protection from the SARS-CoV-2 which causes the disease COVID-19. If you need any assistance, ESC ( is here. We have a board Certified Industrial Hygienist (CIH) on staff and have been providing respiratory protection services to our clients for thirty years. ESC has the credentials and experience to help you with your respiratory protection needs. We are just a telephone call (800-226-1735) or an e mail away ( Contact us today!