PONE-D-20-18656

Subject validation of reusable N95 stop-gap filtering face-piece respirators in COVID-19 pandemic

PLOS ONE

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Academic Editor

PLOS ONE

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Partly

Reviewer #2: Yes

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2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: Yes

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3. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

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4. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

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5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: • A lot of COVID-19 containing droplets have been reported to be in 1-5um as well. The described tests do not address this potential infection range, so the authors should either comment on whether the tests that they chose would by default be successful in stopping the larger droplets as well, or perform a round of tests looking these larger droplets.

• Can the authors comment further on whether overweight/obese users would be able to benefit from the silicone mask in similar efficacy, since that is also a large demographic of potential users and the cohort used in this study skewed significantly towards the more uncommon underweight/normal range.

• The numerical values between the N95 and the SSM are vastly different. I felt that there needs to be further specific elaboration on why the values are so disparate and clearer explanation on what let to these results.

• While a valid alternative to commercial N95s, the authors need to be careful when claiming this is a straightforward or simple N95 alternative to produce. To manufacture the SSM, it requires a relatively well outfitted manufacturing facility and know-how that is not always common outside of large cities/institutions (silicon moulding, injection moulding, 3D design, etc) and the supplies that were used are also scarce or unavailable to the general public. There needs to be further elaboration on how this potential roadblock to production at scale can be overcome. Either by simplifying the design and using alternative materials, or by directly enlisting industry partners that have the capacity and ability to produce the SSM.

Reviewer #2: The paper presents on the validation approach for reusable respirators that can be used at hospitals and front line workers to access the reliability, reusability of N95 masks with replaceable filters. The paper is timely and should be published as is.

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Reviewer #1: No

Reviewer #2: No

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Subject validation of reusable N95 stop-gap filtering facepiece respirators in COVID-19 pandemic

PONE-D-20-18656R1

Dear Dr. Ng,

We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication.

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Kind regards,

Vahid Serpooshan, PhD

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: All comments have been addressed

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2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

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3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

**********

4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

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5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

**********

6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: I would caution the authors about assuming that more facial tissue (re. obese and overweight users) would create a better in all, or even most cases. Depending on the unique user, a one-size-fits-all mask approach which seems to be the chosen approach for translation here might not cover a sufficient range of the general population's facial features. As adding 3D facial mapping for each user is unfeasible for a stop-gap design, will add to production steps and time, and raise the already high price per unit of the proposed design here, I would suggest that several sizes of masks be designed in the production stage with industry collaborators, and a small section be added in the manuscript commenting on that.

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7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

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Reviewer #1: No