FDA Webinar

Moderator: Irene Aihie

07-07-20/12:00 pm ET

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FDA Webinar Series - Respirators for Health

Care Personnel Use during COVID-19 Pandemic

Moderator: Irene Aihie

July 07, 2020

12:00 pm ET

Coordinator: Welcome and thank you all for standing by at this time all participants will be in 

a listen-only mode until the question and answer portion at the end of today's 

presentation. At that time if you would like to ask a question, you may press star 

one on your phone. 

As a reminder, if you have not logged into WebEx please do so you can view 

today's presentation. Today's conference is being recorded. If you have any 

objections, you may disconnect at this time. I would now like to turn the call 

over to Irene Aihie Thank you, you may begin.

Irene Aihie: Thank you. Hello, and welcome to today's FDA webinar. I'm Irene Aihie of the 

CDRH Office of Communications and Education. Welcome to the third CDRH 

webinar in our webinar series on the topic of decontaminating respirators for 

health care personnel during the COVID-19-time damage.

Today we would be joined by experts from FDA Center for Devices and 

Radiological Health and colleagues on the Occupational Safety and Health 

Administration and the Centers for Disease Control. During this webinar, FDA 
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will speak in detail about decontamination systems for respirators, including 

specific methods for decontamination, evidence of potential effectiveness, and 

best practices and common challenges in emergency use authorization request 

submission. 

Following the presentation, we will open the line for your questions related to 

the information provided during the presentations. Colleagues from both CDC 

and OSHA will join us to assist with the Q&A. Now I give you Dr. Binita Ashar 

from FDA Center for Devices and Radiological Health.

Dr. Binita Ashar: Thank you very much, Irene. Hello, everyone, and welcome to today's third 

session in our bi-weekly webinar series on personal protective equipment. My 

name is Binita Ashar, and I'll be moderating today's webinar where we're 

continuing our discussion on respirators for use by healthcare personnel during 

the COVID-19 pandemic response. 

In the first webinar launching this series, FDA, CDC/NIOSH, and OSHA 

provided a broad overview of respirators used in health care that would serve as 

the foundation upon which we would then devote subsequent sessions for a 

deeper dive.

The respirators we've been focusing on are the N95 respirators, which are 

disposable facepiece filtering facepiece respirators that cover a user's airways 

or nose and mouth and offer protection from particulate material and an N95 

filtration efficiency level.

In our second session two weeks ago, we discussed the various EUA 

emergency use authorizations that have been issued for the respirators and 

illustrated the ongoing issues related to addressing the supply-related concerns 

with the necessity for ensuring that respirators for our healthcare workforce are 
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indeed providing adequate respiratory protection.

In today's third session of our webinar series, our topic is decontaminating 

respirators for healthcare personnel use during the COVID-19 pandemic. 

Decontamination systems are devices intended to decontaminate certain 

medical devices, such as compatible respirators so that they can be reused by 

healthcare personnel. 

A decontaminated respirator should only be used when there are insufficient 

supplies of newly approved cleared or authorized respirators. Today, the FDA 

has authorized nine decontamination systems for high-level tier-one 

decontamination. Each of these systems is unique and their assessment 

complex. 

To discuss the various considerations, best practices and common challenges in 

emergency use authorizations for decontamination systems for respirators for 

healthcare personnel use, we have with us today, Captain Elizabeth 

Claverie-Williams, Assistant Director for the reprocessing and personal 

protection team. Dr. Clarence Murray III, team leader, sterility devices team, 

and Dr. John Weeks Scientific reviewer. Captain Claverie and Dr. Murray are 

from FDA’s Center for Devices and Radiological Health, Office of product 

evaluation and quality. and Dr. Weeks is from FDA’s Center for Devices and 

Radiological Health Office of Science and Engineering Laboratory. 

Captain Claverie will begin the presentation and hand it over to Dr. Weeks and 

Dr. Murray. When they conclude they will hand the session back to me and we 

will open the line for questions. With that, I'd like to ask Dr. - Captain Claverie 

to begin today's presentation.

Capt. Elizabeth Claverie-Williams: Good afternoon everyone, and welcome to this presentation 
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on decontaminating respirators the healthcare personnel use during COVID-19 

pandemics. Next slide, please. During the COVID-19 pandemic, the reuse of 

N95 respirators has become a critical strategy to mitigate shortages against 

devices.

We want to ensure that our health care personnel have access to respirators that 

effectively filter particulates and have been adequately decontaminated to 

prevent the undue risk of exposure, and that the benefits of using these devices 

outweighs the risks.

Once we begin receiving EUA requests for respirator decontamination, we 

worked to provide guidance to ensure there are clear, consistent 

recommendations to facilitate the development of this novel approach for 

respirator reuse. 

This guidance was developed to communicate a recommended framework to 

our stakeholders who are developing microbicidal processes intended to make 

respirators safe for subsequent uses. Let us now discuss the methods for 

decontamination and bioburden reduction of N95 respirators. 

We understand that there are many different microbicidal processes, such as 

vaporized hydrogen peroxide, and steam beingexplored for this purpose.. 

Different microbicidal processes may have different utility depending on the 

modalities, use environment, context of use, and the intended outcome of the 

process. Despite this variability, the guidance presents a set of considerations 

that are generally applicable to most decontamination and bioburden reduction 

processes.

We have intentionally differentiated between what we consider “disinfection”

and “bioburden reduction” in order to clearly communicate different degrees of 
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potential microbicidal effectiveness. The initial evidence of potential 

effectiveness comes from the demonstration of the microbial inactivation.

Later in our presentation, my colleagues will provide more details about our 

tiered approach for these systems and how we have differentiated between 

respirator decontamination and bioburden reduction. At a high level, all 

pre-EUA requests for respirator decontamination or bioburden reduction

systems must provide some evidence of potential effectiveness at achieving a 

controlled, repeatable microbicidal endpoint.

Depending onthe intended microbicidal endpoint and the target Tier, this

evidence may include microbicidal effectiveness testing performed by the 

sponsor directly, or it may include valid scientific evidence from other sources, 

such as scientific literature. 

Finally, we will discuss observations, common challenges, and 

recommendations for the emergency use authorization. During this webinar, we 

will provide recommendations for stakeholders considering submitting an EUA 

request for a decontamination or bioburden reduction system for respirators or 

surgical masks. 

We will also provide some observations regarding common challenges we are 

seeing for theseEUA submissions. These recommendations and observations 

were used to write the aforementioned guidance document, which we will now 

discuss in more detail.

As a respectful reminder, decontaminated respirators should only be used 

when there is an insufficient supply of new approved cleared or authorized 

respirators. Next slide, please.
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FDA recently issued this Immediately in Effect Guidance. Recommendations 

for sponsors requesting EUAs for decontamination and bioburden reduction 

systems, for surgical masks and respirators during the Coronavirus disease 

(COVID-19) public health emergency.

Our guidance gives recommendations for submissions of an evidence-based 

approach to decontamination and bioburden reduction systems. This guidance 

document outlines our evidence-based approach for reviewing the 

decontamination bioburden reduction EUA request.

It outlines recommendations for how a sponsor of an EUA, may use valid 

scientific evidence to demonstrate the safety and potential effectiveness of their 

proposed system, as well as how to address known and potential benefits and 

risks related to the emergency use of their system. 

Now, I will discuss an overview of the Tiers.. Excuse me. Section 4B of this 

guidance document provides an overview of our Tiered approach for decontamination and 

bioburden reduction systems. We will go into more detail later, butat a high level, we are 

considering three Tiers of microbicidal processes for use with respirators and surgical masksunder 

an EUA. Tier one has the most stringent criteria of the three tiers and includes decontamination of 

surgical masks and respirators for single or multi-user reuse. Tier two includes decontamination of 

surgical masks and respirators for single user reuse only.

And Tier three is for bioburden reduction of these devices for single-user reuse 

only, and only as a supplement to existing CDC reuse recommendations. Each 

tier addresses a different microbicidal endpoint as we will discuss shortly. 

Finally, I will discuss the recommended content of pre-EUA submissions and 
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EUA requests. The guidance also provides recommendations for the content of

pre-EUA submissions, and EUA requests aligned with our evidence- based 

approach for assessing the safety, possible effectiveness, and benefit-risk 

analysis of these systems. In addition to the demonstration of microbial 

effectiveness, you will need to provide evidence that cycle conditions do not 

affect the respirator.

In other words, please include evidence to ensure that the decontamination or 

bioburden reduction system is not damaging the respirator or surgical mask in a 

way that reduces the device's performance to an acceptable level. For example, 

after the maximum number of decontamination or bioburden reduction cycles, 

a respirator should be able to maintain its function as demonstrated by the fit, 

filtration and breathability of the device.

The microbicidal process should be compatible with the materials of the 

respirators, including the strap, and should not degrade the device. For 

example, we are aware that respirators containing cellulose are not materially 

compatible with microbicidal processes that use hydrogen peroxide. 

We ask that EUA sponsors identify any respirator or mask materials known to 

be incompatible with your proposed process. We also ask that all EUA sponsors 

clearly specify the maximum number of process cycles that can be applied to a 

respirator or mask using their proposed system. It is our expectation that the 

maximum number of cycles is supported by valid scientific evidence that 

demonstrates the maintenance of the PPE performance characteristics after the 

maximum number of cycles.

EUA sponsors should provide a clear mechanism for tracking the number of 

cycles that have been applied to each piece of PPE. Finally, we considered the 

residuals, labeling, and mitigations to reduce risk. When reviewing these EUA 
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requests, we also evaluate the safety of the PPE user and any personnel that may 

be operating the microbicidal process.

We encourage sponsors to include mitigation measures like engineering 

controls, process controls, and labeling to reduce the risk of 

cross-contamination between respirators, or between people and contaminated 

respirators. We encourage regular monitoring of disinfection or bioburden 

reduction personnel for signs of COVID-19 or other respiratory infections.

And lastly, for the disinfection of bioburden reduction methods that are 

intended for single-use reuse, we expect sponsors to do everything reasonably 

possible to reduce contact between pieces of contaminated PPEs and to reduce

respirator contact with anyone other than the specific user. Single-user reuse 

systems should also include a mechanism for ensuring that each piece of PPE is 

returned to its original owner.

All of the recommended content for the pre-EUA submissions and EUA 

requests is focused on ensuring that the FDA review personnel have the 

scientific evidence and risk mitigation information needed in order to perform a 

complete review of the EUA. Now, my colleague, Dr. Jon Weeks, will go into 

more detail regarding how we developed our evidence-based approach to 

reviewing these submissions. Jon.

Dr. Jon Weeks: Thank you, Captain Claverie. Good afternoon. I'm Dr. Jon Weeks and I will be 

discussing information on evidence-based approaches and our tiered approach 

for decontamination and bioburden reduction and specific modalities we have 

received submissions regarding the decontamination or bioburden reduction of 

N95 respirators and surgical masks. Next slide, please.

From sterilization and disinfection, we have a general understanding of the 
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resistance of microorganisms to various commonly used chemicals like 

vaporize hydrogen peroxide and ozone as well as heat. It is generally observed 

that spores and Mycobacterium are the most resistant sitting various modalities.

Non-envelope viruses and vegetative bacteria exhibit intermediate resistance, 

and enveloped viruses, such as SARS-CoV-2, commonly known as 

Coronavirus are more susceptible.

Based on this hierarchy we’ve established a tiered approach discussed on the 

next slide. For modalities that do not follow this hierarchy of resistance, we 

recommend contacting FDA at the address on the screen to discuss appropriate 

organisms to use for validation testing. Next slide, please.

The tiers were designed to create a margin of safety and provide confidence that 

microorganisms, including SARS-CoV-2, would be inactivated. We, therefore, 

recommend that demonstration of activation of only enveloped viruses or 

SARS-CoV-2 alone does not provide a sufficient margin of safety for 

decontamination, or bioburden reduction systems. 

Our recommended for non-enveloped viruses, vegetative bacteria, 

mycobacteria, and spores allow for confidence that SARS-CoV-2 and possibly 

other pathogenic microorganisms are inactivated.

While SARS-CoV-2 is utmost importance, healthcare personnel are commonly 

exposed to other opportunistic pathogens, which may cause additional 

infections in the wave of COVID-19. Additionally, demonstration of the only 

inactivation that SARS-CoV-2 may not provide a sufficient margin of safety as

we do not have clear information on the infectious dose or know what level of 

exposure to the pathogen is safe for reuse.
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Demonstration of inactivation of more resistant microorganisms provides a 

margin of safety to help prevent the spread of SARS-CoV-2 and possibly other 

pathogenic microorganisms. For modalities that do not follow the classical 

hierarchy of resistance, we recommend that microorganisms that are resistant to 

the chemical agent or radiation are used for the testing to build in a margin of 

safety. 

For all systems, we may ask for a justification for organisms to be used for 

validation to demonstrate that those selected are appropriate for the testing 

performed. We understand that the ability to get time in a microbiology testing 

laboratory or the supplies for testing are limited in the current situation. To 

ensure that the testing will address our concerns, we recommend discussing it 

with us before conducting your testing. 

We welcome interactions and are willing to review protocols to ensure that the 

testing will contain adequate conditions to address the microbial effectiveness. 

The table on the screen provides information on the three tiers, including the 

intended use of the respirator, and the microbiological acceptance criteria. 

Note that for tier one, which is for single or multiple users, Sponsors should 

provide evidence to demonstrate inactivation of greater than or equal to six logs 

of the most resistant spores, or Mycobacterium species. For tier two, which is 

only for single users, sponsors to demonstrate the ability to inactivate greater 

than or equal to six logs of three non-enveloped viruses or two gram-positive 

and two Gram-negative vegetative bacteria.

For tier three, which is only for single users, and only for supplementing 

existing CDC recommendations for reuse. Sponsors should provide evidence to 

demonstrate inactivation of greater than or equal to three logs, a non-enveloped

virus or two gram-positive and two gram-negative vegetative bacteria or 
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provide other evidence that demonstrates the specified critical parameters, 

which is a similar level of inactivation of microorganisms. 

Ideally, we recommend the use of new FDA cleared or authorized and NIOSH 

approved respirators, but we understand that this is not always possible. In 

situations where a new respirator cannot be used, we recommend that 

decontaminated respirator be used. The best option would be a Tier 1

decontaminated respirator at these decontamination methods has demonstrated 

the greatest reduction of some of the most resisting microorganism to modality.

We understand that not all facilities have access to tier one decontamination 

systems and recognize there is a need for additional alternatives. Tier two 

decontamination systems will have demonstrated the ability to inactivate 

moderately resistant organism, and we feel render the respirator state for a 

single user. 

To further reduce the risk for tier two and tier three, we will recommend explicit 

labeling and precautions to prevent cross-contamination of the respirators. 

While tier three will not have demonstrated the same level of microbial 

inactivation, i.e. six logs versus three log reduction, we believe that when these 

systems are used in conjunction with existing CDC recommendations for reuse, 

it will be safe for a single user. 

An example of the existing CDC recommendations for reuse would include 

placing respirators into a paper bag or other breathable bag for five days 

between users of the respirator, please refer to the CDC plus page for additional 

recommendations. Next slide, please.

Sponsors have submitted pre-emergency use authorization factors claiming the 

respirators can be decontaminated or bioburden reduced by many modalities. 
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These are the included vaporized hydrogen peroxide, moist and dry heat, 

low-temperature steam, ethylene oxide, vaporized peracetic acid, chlorine 

dioxide, UVC irradiation, supercritical carbon dioxide, bleach wipes and 

ozone. We have or are in the process of reviewing the data presented reports 

these claims.

For many of these modalities, the classical hierarchy of resistance of 

microorganisms applies. However, there are some modalities that these do not 

apply to. As noted in the guidance for these modalities, we recommend that 

sponsors contact FDA to discuss what organisms and testing to be conducted to 

demonstrate the device will meet one of the three tiers of decontamination or 

bioburden reduction.

Based on our review EUA and pre-EUA submissions for decontamination and 

bioburden reduction systems, we've observed some common pitfalls and have 

some recommendations. Please remember to include details on how the

validation testing was conducted and differences in conditions between various 

sites or reported literature, if you are leveraging published data. We’ve

particularly observed that issue or challenge in the VHP submissions. 

For parasitic acid, ozone, chlorine dioxide, supercritical carbon dioxide, and 

any modality that is likely to have residuals, please include a risk assessment 

indicating how the residual are acceptable as well as the risk assessment 

demonstrating the person conducting the decontamination did not risk of 

exposure to the chemical sterilant.

For UVC irradiation, please demonstrate the shadowing and penetration into 

the internal fibers of the respirator do not pose a risk that the decontamination 

system will be unable to provide adequate microbial inactivation. 
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Please also remember to adequately demonstrate that the respirators are not 

damaged by the decontamination cycle. I will now turn it over to Dr. Clarence 

Murray to discuss evidence of potential effectiveness.

Dr. Clarence Murray III: Thank you Dr. Weeks for your description of the various types of 

specific methods for decontaminating and bioburden reduction of N95 

respirators. Good afternoon. My name is Dr. Clarence Murray III and I would 

like to thank you all again for attending this webinar. 

At this time, I would like to focus our attention on the second bullet point which 

is entitled Evidence of potential effectiveness. In this bullet, I would like to 

identify and briefly describe and discuss each of the critical pieces of evidence 

that is needed to determine the effectiveness of a method used to decontaminate 

or to reduce the bioburden.

In addition, I will discuss the evidence needed to demonstrate that the N95 

respirator has been decontaminated. Now, I am going to walk you through the 

sections of the pre-EUA submission and highlight a few points to consider. In 

the section focus on the proposed intended use, in the discussion of the request, 

there should be a clear discussion of the specific modality and where the 

decontamination or bioburden reduction system will be used to decontaminate 

or reduce bioburden on the N95 respirators.

In your section described in the description of the technology. This section 

should describe the mode of action of the technology, in addition, describe any 

unique features of the technology and the chemistry and the physics of the 

decontamination or bioburden reduction system. Finally, this section should 

describe the most resistant organisms to the system. 

In the section labeled description of the process control, including the critical 
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cycle parameter, this section should describe the baseline control of the process 

parameter and critical parameter which includes time, temperature, pressure, 

humidity, dose, and concentration.

In addictions, this section should also describe the process parameters and the 

critical parameters used to decontaminate or reduce the bioburden on N95 

respirators. 

In the section focused on validation of decontamination or bioburden reduction, 

(Tiered Approach) The guidance document entitled Recommendations for a 

sponsor requesting EUA for decontamination and bioburden reduction system, 

for surgical masks and respirator during the Coronavirus disease COVID-19 

public health emergency provide guidance on microbiological testing for tier 

one, tier two and tier three approach. 

Also, the validation evidence should provide a description of the N95 

respirators' load and configuration in the system. And clarify whether the N95 

respirator is being inoculated with the challenge organism or process challenge 

devices is being constructed with their biological indicator in N95 respirator.

Finally, this section should include validation evidence describing how the 

system's critical parameters will be monitored by the health care personnel. 

In the section focus on material and respirator compatibility, this section should 

include either testing evidence or literature evidence that demonstrates the 

material used in the construction of the N95 respirator is compatible with a 

specific method.

In the section focused on process residues. This section should address whether 

the residues that are produced through the decontaminating or bioburden 
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reducing modalities are at safe level. Also the occupational resources from the 

process should be evaluated so that the risk of the process residues is assessed 

and toxicologically understood.

In the section focused on the number of decontamination slash bioburden 

cycles that specific N95 respirator can withstand and still demonstrate: this 

section should describe the filtration efficiency performance using 42 CFR Part 

84 and or the NIOSH modified testing methodology. 

For breathability, the section should be based on 42 CFR Part 84.180. For fit 

testing, you should look at OSHA's regulations 29 CFR 19.134. Appendix A. 

And also there should be an evaluation of the strap integrity for the claimed

number of decontamination cycles.

The section focused on the chain of custody and safeguards to prevent 

inadvertent exposure. This section should clearly describe the methodology 

used to ensure that there is no cross-contamination in the decontaminating or 

the bioburden reduction system. 

In addition, you should describe how cross-contamination with the N95 

respirators are mitigated among the healthcare personnel, health care facilities, 

and decontamination facilities. 

In the section that is focused on labeling, this section should focus on the 

information that need to be shared through fact sheet, instruction to healthcare 

personnel, instruction to healthcare facilities, and the decontamination 

facilities. For examples of labeling for authorized EUAs, you can review our 

website for EUAs that have been authorized.

We also want to remind you that the technical data, is just one part of the 
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evidence that is needed in the request. And now let's discuss the additional

evidence that is needed in your pre-EUA. 

The first additional evidence, is the regulatory status and history. The section 

describes the decontamination or bioburden reduction system regulatory

history. This can include the system's history with the FDA and other foreign 

countries and the clear slash approved intended use.

We understand that some devices are being reconfigured and providing a

510(k) number will suffice this concern. And for novel systems, we recommend 

that you provide as much information as possible. The second additional 

evidence that I will mention is the unmet public health need question.

This section provides a discussion focused on the public health need of 

decontamination for the bioburden reduction system and the unmet need or 

needs the potential emergency you use authorizations would address. This 

discussion also should identify any approved alternative decontamination, or 

bioburden system and those systems availability and adequacy for the proposed 

use. 

The next additional evidence I would like to discuss is the risk and benefit 

assessment. This section discusses the risks and benefits associated with the 

decontamination or bioburden system that includes a discussion of the risks and 

benefits of decontaminating or bioburden reduction of N95 respirators. 

And finally, the last piece of evidence that I would like to discuss is the 

estimation of the number of decontamination or bioburden reduction system. 

The projection regarding the quantity of the decontamination or bioburden 

reduction system that will be available on hand and the surge capability of the 

manufacturing site to be provided. 
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In closing the evidence of potential effectiveness is a combination of addressing 

the unmet public health need question and understanding the landscape of the 

medical device shortage in combination with the validation data, 

microbiological data, control of the process and its critical parameters. 

respirator functions, understanding the risk of process residue, occupational 

exposure, the risks and benefits in the decontamination or bioburden reduction,

potential of cross-contamination, labeling, chain of custody and safeguards to 

prevent inadvertent exposure and human factors to determine the effectiveness 

of the evidence in a pre-EUA request submission. Now I will turn the 

presentation to Dr. Weeks to talk about the common challenges and 

observations and recommendations.

Dr. Jon Weeks: Thank you, Dr. Murray. I would like to finish off the presentation with some 

challenges and recommendations to address these challenges. This information 

is the principal for all sponsors of the decontamination and bioburden reduction 

system. One common challenge is understanding the microbiology of your 

decontamination or bioburden reduction system. 

Understanding the hierarchy of resistance and micro microbiology is important 

so the testing is performed using the correct organisms to the modality and here 

being demonstrated. To be used to establish the appropriate margin of safety for 

the cheer being demonstrated.

Another common challenge is the demonstration that testing is performed using 

worst-case conditions. Worst-case conditions can be thought of through 

multiple avenues, including worse case locations on the respirator, shorter or 

longer exposure times, higher or lower concentrations, soils used during the 

testing, and load configuration during the validation testing. 
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For this, we recommend sponsors provide a description or the protocol used for 

validation and demonstrate that you can decontaminate respirators. This should 

include information on how respirators are inoculated, soils used for suspension

of the microorganisms, and a description of how the chamber was filled to 

create a worst-case validation of the microbial inactivation. 

While we understand that visibly soiled respirators will be excluded from 

decontamination or bioburden reduction, by wearing a respirator they will be 

exposed to many soils, such as sebum, saliva, mucus, and possibly SPF lotions

that will likely transfer to the respirator through use. 

All of these items should be considered like conducting your validation testing, 

and when providing this information to the FDA for review. I would like to 

reiterate that we understand that the ability to get time in microbiology testing 

laboratories and supplies for testing are limited in the current situation. 

To ensure that the testing will address our concerns, we recommend discussing 

with us before conducting your testing. We welcome interactions and are 

willing to review protocols to ensure that the protection will contain adequate 

conditions to address the microbial effects.

Validation testing is designed to test the limits of the decontamination cycle. 

The worst-case conditions used in the validation testing will be used to design 

the critical process parameters required for production conditions or the critical 

process parameters required to achieve the intended level of microbial 

inactivation. 

If the validation testing is conducted in a small-scale chamber, we will need 

information on how the process has been scaled to a production size and how 

has determined that the critical process parameters are equivalent. 
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Monitoring of the cycle can be another challenge we have experienced when 

working with sponsors. Monitoring can be achieved through biological 

indicators, chemical indicators or integrators, temperature probes, relative 

humidity monitors, and UV dosimeters to name a few. We recommend that you 

provide a mechanism for the cycle to be monitored, and ideally recorded so that 

there is a clear indication for the person performing the decontamination cycle 

to know the cycle have been successfully conducted. Providing a clear 

description of the mechanisms in place to achieve this is also important for 

FDA to understand that the sponsor has a clear understanding of the process. 

For sponsors that are leveraging data from other sources, we commonly 

experienced the sponsors will not provide a correlation between the critical 

process parameters used in the referenced information to the critical process 

parameters of their system. This is important whether the leverage data is used 

for demonstrating microbial inactivation or functionality of the respirators. We 

recommend that when leveraging data you should provide a comparison 

between the critical process parameters and a justification as to how these 

parameters will not affect what is being leveraged. 

For example, if you are leveraging data regarding microbial activation, we 

recommend that you demonstrate your system will provide the same conditions 

described. Additionally, if you're leveraging data for filtration efficiency, or 

other aspects, demonstrating the correlation between the parameters in the 

study and the critical process parameters will be important to confirm the 

conditions are equivalent and will not cause additional damage to the respirator. 

This concludes our presentation and I will now turn the presentation back over 

to Dr. Binita Ashar.

Dr. Binita Ashar: Thank you, Dr. Weeks. Thank you, Capt. Claverie and Dr. Murray for your 
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excellent presentations. I want to emphasize that we are committed to helping 

our frontline health care personnel by ensuring that they have access to 

adequate supplies of safe respirators for use.

While we recommend that health care personnel use FDA approved, cleared, or 

authorized respirators when possible, there remains an important role for 

respirators that have undergone decontamination or bioburden reductions. 

At this point, we have concluded the formal presentation portion of the 

webinar. I'd like to now open it up for a moderated question and answer session. 

We have several subject matter experts from across FDA, CDC, and OSHA. 

We're standing by to help address your questions. Operator may we have our 

first question, please.

Coordinator: Thank you. We would now like to open the lines for questions. If anyone does 

have a question. Please unmute your phone hit star one and record your name 

clearly when prompted. 

Again, to ask a question for today's presentation. Please hit star one and record 

your name when prompted one moment to see if they have questions. And for 

those that raise their hand in WebEx, if you could hit star one so I could 

introduce you for questions. Our first question is from (Amanda Jones), your 

line is open.

(Amanda Jones): Hi I'm just wondering what the information based on for the tier system. You 

said that you had information, but I don't think it was clear on what the 

information is based on the tiered system.

Dr. Binita Ashar: Thank you, Miss Jones. Dr. Weeks or Dr. Murray, would you be able to address

that question, please?
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Dr. John Weeks: So this is the information that we base this on is the resistance of the - hierarchy 

of resistance of microorganisms to various modalities, and chemical steroids. 

So - I believe that with this presentation, we had the hierarchy of resistance of 

microorganisms, and based on that information we determine that. what's your 

one, this would be a demonstration that you've been activated the most resistant 

organisms to the modality, and that would provide the highest - the highest 

margin of testing that this would be safe for you.

And then for tier two and tier three, we wanted to demonstrate an intermediate 

level of resistance so that was looking at something that would be enabled to 

inactivate either non-enveloped viruses or vegetative bacteria and the various 

blog reductions, we felt would provide a significant level of reduction.

(Amanda Jones): So can I just ask one more question. So it's the basic theoretical assumption that

there are no test data that supports real-world evidence, say in actual situations 

what the burden would be on the masks.

Dr. John Weeks: There is not - at this point that we are aware of a study that has determined to be 

actual bioburden on a respirator. But these have demonstrated a high degree of 

moderately or very resisting organisms. So we feel that this should be able to 

activate a high number of non-enveloped viruses, as well as for tier-one should 

help to inactivate other opportunistic pathogens that may be present.

(Amanda Jones): Thank you.

Coordinator: Thank you. Our next question is from (Darren Green). Your line is open.

(Darren Green): I've got a question (unintelligible) literature indicates that by some local alcohol 

fertilizers electrostatic charge found on non-local propylene fibers using in N95 
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which reduces the efficiency from around 95 to 70%. 

(Unintelligible) Most of them are marked with sharpies to indicate both user 

ownership and the current cycles. We're curious about what your thoughts are 

on the impact of sharpies filtration effect on the N95. One of the major 

components within a sharpie looking at it (unintelligible). Seems to be 

(unintelligible) alcohol. Thank you.

Dr. Binita Ashar: Hello, thank you for that question. (Mr. Green). This is Binita Ashar I think our 

team has considered that issue It's a challenge. First of all, we want everyone to 

always use a new respirator first and so these decontaminated respirators are 

really when there is a shortage situation. 

Then concerning the sharpies, there has to be some way to mark the number of 

rounds of decontamination. And so I think this team has discussed several 

options and so perhaps I'll turn it to Dr. Murray, to talk about some of the 

considerations that we have struggled with.

Dr. Clarence Murray III: So thank you, Dr. Ashar. I believe (Mr. Green) - Thank you for the 

question. I think what it is - an issue that we should think about when you think 

about the isopropyl alcohol issue is the amount. So the total volume that would 

be needed to adjust the filtration property. 

And so in the use of a permanent marker, what we try to do is limit the 

interaction of the permanent marker or move to other places on the respirator to 

use as a way to monitor the number of decontamination cycles that a respirator 

could go through.

So your point is well taken, and that is going to cover the mitigation strategies 

that we try to use to make sure that we could want still to count of the number of 
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decontamination cycles to make sure that in the situation when someone has to 

use a decontaminated respirators, that there is a viable way to mark the number 

of times the respirator has been exposed to decontaminating or bioburden 

reduction or modality.

Dr. Binita Ashar: And this is Binita Ashar if I can add, you know, if you mark the respirator itself, 

you'll encounter the problems that you've mentioned, if you put a tag on a 

respirator you encounter the problem of the tags being damaged during the 

decontamination cycle leaving all the tags on the floor. If you put it on the strap 

you encounter problems with Sharpie interfering with the elastic nature of the 

strap.

So, it is a challenge and which we completely acknowledge and recognize, 

however, it is important to keep track of the number of decontamination cycles 

and the ability to get the respirator back to the original user if that what is

intended. Thank you for the question.

Coordinator: Thank you next, we have (David Dark), your line is open.

(David Dark): Thank you very much I appreciate the opportunity you did not specifically 

mention heat as a modality in detail although you did mention generally at the 

beginning of the presentation either wet heat or dry heat has used effectively 

excluded in modality or what are the comments would you have to make 

additions as decontamination.

Dr. Binita Ashar: Perhaps. Captain Clarverie, would you be able to address this question.

Capt. Elizabeth Claverie-Williams: Hi, my apologies for asking could you please repeat the 

question?
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(David Dark): Certainly, although heat as a decontamination modality was mentioned 

generally with the - being part of the presentation it was not specifically called 

out the way some of the other modalities were either wet heat or dry heat. Can 

you comment specifically on heat as a decontamination modality? Is it 

acceptable? There are no residuals. So, are there any specific concerns the FDA 

has about using heat as a decontamination modality?

Capt. Elizabeth Claverie-Williams: Thank you very much. That's a very good question. And let 

me start very general in very general terms and answer when I did my portion of 

the presentation, I only mentioned as you said, I mentioned vaporize hydroxide 

and steam among others.

We have authorized modalities as well as moist heat and vaporized hydrogen 

peroxide. We've authorized a combination of vaporized hydrogen peroxide and 

ozone. We are examining many modalities, including dry heat and we are not 

opposed to dry heat at all. 

It's just that we're still in our review process as relates to dry heat. I'm going to 

ask my colleague, Dr. Murray, if he has anything in addition to add to what I've 

just said in response to the question and Thank you, sir, for the questions.

Dr. Clarence Murray III: Thank you Capt. Claverie, I think you summed it up, I think the 

point of the few pages wasn't to necessarily highlight or to put a spotlight on 

anything or to leave any modalities out. What we would say that everything is 

under - it has an opportunity to be under review If the pre-EUA or EUA were 

submitted to the agency.

(David Dark): Great. Thank you very much. Understand that thank you.

Coordinator: Thank you. Next, we have (Samir Bamberg) your line is open. Hi, this. Can you 
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unmute your phone?

(Samir Bamberg): Can you hear me now?

Coordinator: Yes, we can hear.

(Samir Bamberg): Okay. A two-part question. The first deal with the residuals in the respirators, 

given the expertise of CDRHs labs as your group considered putting in place a 

standard protocol for measuring the residuals over time in the respirators.

That’s part one. 

And the second part. Here in Boston, there appears the hydrogen peroxide was 

interacting with the materials getting off. Now odors. Therefore, the residuals 

are affecting the re-users and how you are (unintelligible)?

Dr. Binita Ashar: Thank you for the question. Yes, residuals are an important consideration and a 

concern to us. To address the question of how we're looking at residuals and 

potential options moving forward. Dr. Weeks are you able to comment?

Dr. John Weeks: Yes, I can start, and then I'll also pass that over to Dr. Murray. So, we are 

concerned about residuals and we do think that the residuals should be tested 

and assessed. We have seen that this has been conducted through various 

methods. 

This has been done through extraction as well as the use of monitors. And this 

point in time, I don't know that the agency is working towards developing a 

standardized method. Dr. Murray might be able to provide some more 

information about it.

Dr. Clarence Murray III: So thank you, Dr. Weeks So, to address the question of residual, we, 
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as an agency work very closely with the international standards organizations. 

And so in there we are, members, of the working group that deals with the ISO 

10993-12 where we look at methodologies and sample preparation things like 

that. 

And so, with that, we have many of our colleagues in the center that work on 

that and so, and then also in that you have many different sponsors who will be 

part of that and so, what we try to do is make sure people are using the latest and 

greatest techniques that are out there and ...

(Samir Bamberg): Could you be specific (unintelligible) the first 109993 are on biocompatibility. 

So could you be specific as to the protocols you're using?

Dr. Clarence Murray III: So here is what I would say we need the sponsors to tell us how they 

are performing their exhaustive extraction in some cases, or what types of 

systems one would use to evaluate the number of residues that would be coming 

off of modalities that will have process residue.

You know, the case of hydrogen peroxide is always interesting, because there's 

been a lot of discussion about the biocompatibility and cytotoxicity endpoint 

results.

And so like I said, before we made it to be the sponsors' responsibilities and 

make sure they have exhausted extraction so that they could mitigate in the 

process residues and then we asked them about exposure information they have

over time. Let's talk about it.

Dr. Binita Ashar: And if I can add. This is Binita Ashar. These are significant concerns you are on 

your separate because of the risk of residuals being inhaled and being on having 

toxicity associated with that. 
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And so we were in partnership with our CDC, NAIC and OSHA colleagues 

when the question of residuals arises, and so as Dr. Murray was saying it is, you 

know, modality-specific. The testing provided is the testing that we're given 

and we're assessing that, but it is with a significant amount of scrutiny. I don't 

know if our OSHA colleague (Andy Levinson) has anything more to add?

(Andy Levinson): No, we don’t. We review also on a case by case basis as the data comes in. You 

know, we of course have accepted FDA methods. OSHA is open to considering 

other methods that employers outside of healthcare settings and employers 

provide. But again, it is case by case, what's the objective data that the employer 

has provided?

(Samir Bamberg): Right. And then the subsection (unintelligible) carbon dioxide mentioned that

was used during anthrax, h1n1 (unintelligible). It's been cleared both by the 

EPA and the FDA. But we have yet to see anything coming from your group 

with respect to the state of carbon dioxide.

Dr. Binita Ashar: Thank you for that observation. I think as Dr. Murray mentioned, we're open to 

evaluating all methods of decontamination and so we're not able to talk about 

the status of a particular application or the status of a particular modality even 

beyond the authorizations that have already been issued.

(Samir Bamberg): Thank you.

Coordinator: Thank you. And our last question comes from Dr. (Peter Crannis). Your line is 

open.

Dr. (Peter Crannis): Thank you for taking my call. So I'm in Maryland and (unintelligible) 

benefits from various decontamination systems. And I think FDA does support 
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some research by I think it was ARA in Florida a couple of years ago they 

looked at, I think hydrogen peroxide and also UVC radiation and sort of stress 

the idea about, you know, costs of the systems as well as whether or not there 

were points of service, whether they involve, you know, logistics risks and 

moving, you know, contaminated mass from outside of the units or their use.

And just as a general question now we're sort of faced in our hospital we're 

using a one size fits all masks. They're not - these are given to staff that was 

never properly set it or they're given, say, say regular masking, they'll say 

they've been fitted for a small mask. 

And then they're not performing feel test. So my question is, would it logically 

I'm kind of thinking I'd rather have a fitted mask that I knew fit my face and go 

through tier two or tier three contamination system UDC or something else 

- whatever, than be given an unfitted, unfield-tested mask. Does that make 

sense?

Binita Ashar: Yes. I think it does. I mean we all struggle with what's better; using a new mask, 

using one that's been decontaminated or using one that's new but doesn't fit 

well. You know, I'm going to ask my NIOSH colleague, Jeff Peterson, to see if 

he has any initial thoughts, particularly around fit testing.

Jeff Peterson: This is Jeff Peterson. So, you know, the requirement for individual fit testing 

follows OSHA though, you know, I'll give my perspective and then point to 

Andy if he has anything. But, you know, certainly, I think to maintain the 

approval of a NIOSH approved device, one of the requirements is that are 

identified (unintelligible) limitations of use is the label indicates that they must 

be moved in accordance with, you know, the appropriate regulations and that 

certainly does point to the OSHA regulations.
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So, you know, you can't assume that a respirator is going to be effective and do 

a proper selection unless you understand the hazards and understand the 

amount of reduction that's needed. And the only way going forward on an 

individual level, to insure that that level of protection is going to be maintained 

is by doing an individual fit test. 

So the importance of the fit test is crucial no matter what (unintelligible) and 

what a decontaminated or a new device or whatever. So, you know, there are 

indications that one size fits all, one size fits most shouldn't be taken as a 

(unintelligible) about doing fit testing. So (Andy), do you have anything to add?

Andy Levinson: Yes, Jeff. Thanks. So I think Jeff is spot on. The fit testing is vitally important 

because without the fit testing you don't know whether or not it's going to fit 

you and you don't know if it will provide the expected level of protection. 

We are aware there are some shortages and limitations in fit test supplies and 

OSHA and NIOSH have actually put out guidance on how to make your own fit 

test solutions, which is completely acceptable within the OSHA standards.

I think at a minimum there is certainly no reason why the users couldn't figure 

out or couldn't be trained how to do a user field check to figure out if they have 

at least have the grossest levels of leakage and the ones that are absolutely, you 

know, the worst failures. 

Now in terms of the overall selection and decision process, what OSHA is 

going to do when we come into a workplace, is we're going to look at the whole 

process that the employer used and to what extent they tried to comply with the 

standard to the extent possible.

So before we even get into the decontamination and reuse of respirators, we 
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would be looking at number one, is the employer trying to comply with the 

standard by buying adequate amounts of filtering facepiece respirators if that's 

their preferred method? We have heard stories about employers who were not 

even trying to provide new respirators at each usage and are going immediately 

to decontamination. And we need to face cost of that as a significant concern.

I would say also there are respirators that are designed to be decontaminated 

and reused, so we would look at whether or not the employer has considered an

elastomeric generic respirators or PAPRs, powered and purifying respirators. 

And then I think after you've exhausted all of those other things, when you're 

falling back to a decision about where you're making - whether you're going for 

different tiers of decontamination, I think that becomes a judgment call based 

on the site-specific facts and what the employer has tried to do and what options 

they have available to them.

So it gets into a little bit more detail, but I think the important overall piece is 

employers must try to comply with the standard to the maximum extent that 

they can, before we would allow any decontamination reuse, extended use or 

crisis standards that are potentially allowable under the OSHA standards.

Binita Ashar: Great. Thank you so much, Andy. And before I turn it back over to Irene, as this 

now ends the question and answer session of this program, I really wanted to 

thank all of our subject matter experts for their participation and all of you for 

your excellent questions. And moreover, for all of the work that you're doing to 

address this COVID-19 public health emergency. Thank you. Irene?

Irene Aihie: Thank you. This is Irene Aihie. We appreciate your participation and thoughtful 

questions. Today's presentation and transcript will be made on the CDRH Learn 

Web page at www.FDA.gov/training/CDRHLearn by Wednesday, July 15th. If 
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you have additional questions about today's presentation, please use the contact 

information provided at the end of the slide presentation. As always, we 

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Coordinator: Thank you for participating in today's conference. You may now disconnect.

END