Frequently Asked Questions

I am a member of the media. Who should I contact?

Please contact Ken Garcia, UF Health Communications, at 352-273-5810 or kdgarcia@ufl.edu

I want to sew. I’m in Gainesville. What should I do?

We very much appreciate your interest in volunteering. However, we have paused production of the masks directed to our UF Health facilities.

I would like to make a donation. What should I do?

Please visit our website for options to make a donation. You can also try to reach out to your local hospital to ask about possible supplies and how best to assist them, knowing that they are likely extremely busy dealing with the current crisis.

Is the sewn non-FDA-approved mask an N95 respirator?

There are very clear and important distinctions between commercially available certified N95 respirators and these masks. An N95 respirator has several key components to pass testing: 1) it is specifically constructed in multiple layers so that it has filtering capacity to 0.3 microns of particle size; 2) it must have breathability so that excess CO2 does not build up over time for the wearer; 3) it must fit tightly to the face as the wearer moves so that a complete seal is maintained at all times; and 4) it should be made of materials that are hypoallergenic and do not damage the skin.

The sewn mask is categorically not an N95 respirator. It has not undergone approval from the U.S. Food and Drug Administration. The material is thought to be superior to the common surgical mask in its ability to block aerosols and droplets, including water, bacteria and other particles. Although the Halyard H600 material has undergone rigorous testing and has been assigned a filtering (N) rating by the manufacturer, it has not, to our knowledge, been tested for use as a breathed air filter by any regulatory body. Although it is not rated as an N95 for filtering breathed air, we do subject it to the same particle filtering test we use for commercial face masks and find that with a properly fitted, snug mask, it appears to provide similar particle filtering properties as commercial masks. Again, this has not been rigorously studied by any regulatory body. We recommend that you be fit tested before using the mask for protection in the same way you would be fit tested for a commercial N95 mask. These masks should not be used to replace N95s at this time.

Where can I find details to make these masks?

We keep the most up-to-date information regarding our mask initiative on the department of anesthesiology’s website: https://anest.ufl.edu/clinical-divisions/mask-alternative/. If you have questions regarding materials, patterns or mask sterilization, please visit this site to find your answer in the FAQs, Mask DOs and DON’Ts and Mask TIPS and TRICKS.

If you are unable to find your answer in these resources, you may call our Anesthesiology COVID-19 hotline at 352-294-5078 and leave a voice message. Someone will respond to you as soon as possible.

How can I get the fabric used to make these masks?

We are using Halyard H600 fabric that is typically used to wrap surgical instrument trays in medical settings. If you are seeking this material, you can contact a local medical facility to ask about availability. We cannot dispense any Halyard fabric to the public at this time. Currently, we are well-stocked in this material. If you interested in donating the material, we suggest you contact your local community hospital to determine if they may be able to accept a donation.

Can we make these masks with other grades of the Halyard material, for instance H100, H400 or H500, or with other fabric?

We are using the H600 grade, which has a slightly higher strength than other grades. For other types of material such as Cardinal products, check the manufacturer’s specifications.

Please be aware that although the Halyard H600 material has undergone rigorous testing and has been assigned a filtering (N) rating by the manufacturer, it has not, to our knowledge, been tested for use as a breathed air filter by any regulatory body.

Is the mask made from two layers of the Halyard H600 wrap?

The Halyard H600 wrap is two fused layers when it is taken off surgical instrument trays. The masks are made by sewing two unfused layers (one blue and one white sheet) together.

If I can get hospitals to donate the fabric, do I need to sterilize it before sending it to community sewers?

In our institution, the material is sterile and has not come into contact with patients. It is being handled by health care workers who are not showing symptoms and who are wearing personal protective equipment. Some sewists are having the material delivered to them so they can cut, organize and distribute it themselves.

What kind of thread should I use?

Any thread can be used provided it is heat resistant. If you are testing materials, please ensure that you check the material’s manufacturer specifications for heat tolerance and use extreme caution.

What kind of wire should I use?

It is important to use 16-gauge craft wire. Aluminum is too soft. If you need to use 20-gauge wire, cut two pieces and make a loop on all ends.

What kind of material should I use for the straps?

We are working out various configurations for the strap material. Several types of materials can be used. We will be sterilizing masks that return from the community by autoclave, so our materials must stand up to these extremely high temperatures or oven temperatures of 165°F for 30 minutes. If you are testing materials, please ensure that you check the material’s manufacturer specifications for heat tolerance and use extreme caution.

How are you sterilizing the masks?

Once the masks are sewn by our teams in the community, they will be sterilized by autoclave before they are distributed to health care workers. After an individual completes fit testing and has used the mask, the mask will undergo UV light sterilization. These masks can be single use based on your hospital’s supply.

What is the duration of use?

The length of time for use varies. Typically, N95 is single-use only. Due to the current conditions, we are choosing to reuse these home-built masks. We will use the masks several times with UV light sterilization prior to discarding them. Typically, one use is 24 hours before sterilization. At this time, Stanford and the University of Tennessee Research Foundation have come to a consensus that commercial N95 masks can be used under autoclave 20 times and under UV light 10 times in the current pandemic.

How is your institution using these masks?

UF Health providers will continue to wear FDA-approved N95 masks when specific safety measures require their use related to a particular patient, a particular procedure or a particular health care provider interface with patients. FDA-approved masks in supply will be used in these circumstances. The non-FDA-approved sewn masks will be given to providers, with eye protection, for use in accordance with the following circumstances and conditions for asymptomatic/non-patient-under-investigation (PUI) care: 1) when performing non-aerosol-generating procedures at any location; 2) in Emergency Department non-respiratory path situations if an N95 mask is unavailable; or 3) when treating Trauma Center patients if an N95 mask is unavailable. In addition, UF Health providers may wear the masks in UF Health facilities or on our health campuses when they are not interfacing with patients. UF Health masks are not currently authorized for use by our health care providers in any other circumstances or in other locations.

The masks are reusable but must be sterilized after 24 hours of use. They cannot be regarded as frontline primary COVID-19 protection.

How can we use these masks in a hospital setting?

The key to using these masks for benefit in a hospital setting is to remember that they do not replace and are not equivalent to N95 respirators. The non-FDA-approved masks have been personally N95 fit tested by more than 20 volunteers. In the people who tested it, the mask passed the sweet or bitter taste test akin to what is used for N95 respirators. However, that does not certify it as an N95 respirator.

If you construct these masks or receive them according to our design, they should be fit tested to your face. If it passes fit testing, please use it but do so with the caveat that these are not commercially produced, third party-certified respirators.

These are community-produced filtration masks created to be extenders of our supply with some increased protection over a standard surgical mask. They cannot be regarded as frontline primary COVID-19 protection.

How are you ensuring that the masks meet quality standards?

Our health care providers will use a home-built mask only if it has been fit tested to verify that when they tie it, there is no inward leak. We are carefully vetting and instructing the people who are sewing these masks. It is important that the masks meet certain quality control criteria given their use in a medical setting.

Should I make this mask at home?

At UF Health, we are using these masks for our health care providers in certain situations. If you are making a mask at home for home use, you can sterilize it by placing it in an oven at 165°F for 30 minutes. Other options may be available. New voluntary guidelines issued Friday, April 3, by the Centers for Disease Control and Prevention, or CDC, advise people to wear cloth or fabric face coverings over their nose and mouth in public settings such as grocery stores and pharmacies, both to protect themselves and others. The CDC said these recommended coverings are not surgical masks or N95 respirators, which are in short supply and need to be reserved for health care workers. The level of protection that N95 respirators provide is generally not necessary for the general public.​ The CDC continues to stress the importance of maintaining 6 feet of social distancing.​

Can the masks be laundered or bleached?

No, this will degrade the Halyard H600 fabric. For sterilization, you may place the mask in a 165°F oven for 30 minutes​.

 Have you tested the carbon dioxide build-up in the mask?

The volume in this mask is no different from other masks, therefore carbon dioxide build-up for an adult wearer should not be an issue.

Are you aware of any chemicals that may have been used in the production of the Halyard H600 wrap that could potentially harm people wearing the masks?

The spunbond meltblown spunbond, or SMS, material is ubiquitous in the medical gowns worn by most, if not all, health care providers, and also is present in N95 masks. We are not aware of any carcinogenic concerns in the masks we have sewn.

I have suggestions about the design. Who should I contact?

Please contact out hotline at 352-294-5078 or email COVID19Research@anest.ufl.edu and someone will respond to you as soon as possible.

Have you started distributing the masks yet?

We are in the early phase of distributing the masks within the UF Health system to some of our health care providers.

Can I buy a pre-made mask? Are you distributing them beyond the UF Health system to other systems in need?

Currently, we are distributing these masks to our health care providers first given the need for personal protective equipment for frontline workers.

My hospital does not want to create these masks because they are not approved by the Centers for Disease Control and Prevention. What is your recommendation for this?

Given the current shortage of personal protective equipment, our sewn masks are intended only to be extenders of our supply, with some increased protection over a standard surgical mask. At our institution, UF Health providers will continue to wear N95 masks approved by the U.S. Food and Drug Administration that are in supply when specific safety measures require their use related to a particular patient, a particular procedure or a particular health care provider interface with patients.

What tests have you done and what testing is ongoing? Do you have data to share?  

The masks have been personally fit tested by more than 20 volunteers. In these tests, akin to fit tests used for N95 respirators, the mask passed the sweet or bitter taste test, i.e., it prevented the taste from reaching the wearer. However, no regulatory agency has certified it as an N95 respirator and we have no additional data.

What autoclave settings (temperature, duration) have you used and how did you place the masks in the autoclave? Is it dangerous to autoclave the masks more than once or, for home use, to place them in the oven more than once?

The autoclave setting is 272°F. After 4 minutes for sterilization and 30 minutes to dry, the masks remain in the autoclave for an additional 15 minutes. The masks then undergo a 30-minute cooling period. We place the masks in a large metal surgical instrument sterilization tray.

The masks can be placed in the autoclave and home oven at 165°F for 30 minutes more than once. We have not done testing after sterilization.

What type of UV light should be used and for how long?

We are currently using Tru-D UV Light for 30 minutes.

Can multiple layers of the Halyard material be used? Is the blue layer different from the white layer?

The blue and white layers have the same properties. In our instructional videos and PDFs, we selected the blue side as the outer side for ease of following instructions. You can use multiple layers but please ensure that the mask is breathable.

Did both prototypes perform similarly on fit testing?

Yes, Prototype 1 with a third strap and Prototype 2 performed similarly.

Can the Halyard material be used as a filter on a fabric mask? Can the material be used as a disposable top layer to extend the use of N95s?

We cannot evaluate uses that we have not tested ourselves. We made cotton masks with pockets to test placing an insert of the material and found they do not provide a tight fit. Thus, we do not know how much that will improve the performance of the mask overall, if at all.

I made these masks and want to donate them to your institution. Are you accepting donations?

UF Health is currently well stocked, both with N95 masks and other general mask options. We suggest you contact other local health care facilities to determine if they may be able to accept a donation.

Can these masks be modified for smaller faces or when there is a difficult fit?

Yes. We have made many changes to the design for those with smaller faces or those who have difficulty with the fit. If you need a smaller mask, print out our pattern for the cone and cut the outer dashed line where the stiches would go. Use that as a new pattern and move the side darts about one-quarter of an inch.

How does the patent pending relate to how the masks can be used in other institutions?

UF Health’s mask initiative is an open-source design in which we have made the instructions freely available for others to use. We do not require the use of logos or credits on masks made using this design.