NEWS RELEASE                                                                                     March 2020

Webinar on Coronavirus Mask Reuse

McIlvaine will hold a webinar on April 2 to discuss and debate the issues relative to N95 mask reuse. Participation will be limited to 25 people, but the session will be recorded, and all registrants will receive the recording.  Selection will be based on a first come first served basis. The session will take place at 10:AM CDT on Thursday April 2, 2020.  To register 

McIlvaine is holding one or more webinars per week on the crisis. Last week, in an 80-minute discussion, mitigation suppliers considered initiatives which would allow business to function while workers were kept safe. This discussion can be viewed at

Wearing of appropriately sterilized and functional N95 masks is a matter of life and death. Unfortunately, the shortage is already responsible for many deaths including in wealthy countries such as the U.S. In fact, the wealthiest countries with the cleanest air are at a disadvantage compared to countries such as China where masks are routinely worn due to pollution levels.

Whereas China has ramped up medical mask production from 20 million to 200 million per day N95 mask production has only increased from 200,000 to 1.8 million per day.  Worldwide production is less than 3 million.  There is a need to protect hundreds of millions of people. It is impossible to ramp up production to meet demand if each mask is only worn for one risky encounter.  On the other hand, if masks could be safely reused 50 times and world production ramped up to 6 million per day there would be sufficient numbers for 300 million people.

The need is urgent in Spain, Italy, the U.S. and many other countries. An immediate solution is necessary.  Fortunately, that solution is now available and commercial. It is simply a matter of employing it now and improving it over time.

Meeting the need

Duke University is successfully employing hydrogen peroxide vaporization to disinfect 500 masks in a 4-hour period.  They are pursuing methods to increase capacity and efficiency.  A 24-hour operation would disinfect 3000 per day.  If the need is to protect an additional 5 million health care workers in critical environments then we need 1700-5100 of such facilities depending on the number of uses per day. Many workers need three sanitized masks per day.

There are many disinfection systems employed in cleanrooms around the world. The production of an additional 1700 could be done quickly and in time to meet some of the urgent needs. It is conceivable that certain cleanroom disinfection operations could be temporarily repurposed to provide sterilization.  In fact, the Duke Hospitals are using a decontamination system in their research facility.

Choosing the best technology

The University of Nebraska Medical Center recently published their procedure for the disinfection of N95 masks using ClorDiSys’ Torch UV Disinfection System. So, there are at least two approaches which are now disinfecting masks cost effectively.

In a paper published in the journal Annals of Occupational Hygiene in 2009, researchers compared and contrasted different methods for sterilizing N95 masks, many of which destroyed the virus but were not good ideas in terms of damage to the masks or practicality of large scale use:

  • Heat in an oven for 30 minutes at 58 degrees Fahrenheit (70 degrees Celsius)
  • Use ultraviolet light for 30 minutes
  • Soak the mask in 75% ethyl alcohol, then let it dry
  • Clean the mask with liquid or vapor hydrogen peroxide
  • Clean the mask with bleach
  • Steam the mask with hot vapor from boiling water
  • Microwave the mask
  • Use extreme heat in an oven or autoclave
  • Soak in soap and water

There are many cost-effective technologies being used in biopharmaceutical cleanrooms. Two experts with decades of experience in biopharmaceutical decontamination will be joining the discussion on Thursday.

Mask design

If masks are going to be reusable, then the mask and media suppliers have the opportunity to redesign their products to maximize the performance under these new conditions.  There are two main considerations:

  • Create a mask which can be sterilized the maximum number of times without deterioration
  • Create a mask with better performance than is justified for a disposable product

Let’s assume that a mask which is more comfortable with less resistance and higher efficiency can be developed.  If it could be used 100 times it could sell for $75 and still be no more costly than a 75-cent disposable version.  The media area is important due to resistance but also cost.  A 50% increase in media could easily be justified in a reusable mask but not in a disposable one.

There are opportunities for immediate development and supply of masks using more efficient media. Using nanofibers or membranes the efficiency of the N95 can be upgraded to N100 and at the same time making the mask more comfortable with less resistance. Some reusable masks are now in production which are washable. Because they do not rely on electrostatic attraction, they can remain efficient for 20 washings. There are many other innovations which will be made possible by making masks reusable. They will be explored in this and future sessions.

The webinar is free to everyone. The program for suppliers is Coronavirus Market Intelligence

Click here for more information

If you have questions or would like to present data during the webinar contact Bob McIlvaine at 847 226 2391 or by email at This email address is being protected from spambots. You need JavaScript enabled to view it.