NIOSH Conformity Assessment 

Letter to Manufacturers

NIOSH CA 2018-1010 

Revised August 2020 

Interim guidance regarding applications for NIOSH Approval of Filtering 

Facepiece Respirators in accordance with the Food and Drug Administration 

(FDA) Final Order published May 17, 2018, and FDA/NIOSH MOU 225-18-006, 

dated November 2017 (included as a reference in this notice)

Revision Supersedes the November 2018 version
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SUMMARY

Beginning August 24, 2020, the National Institute for Occupational Safety and Health (NIOSH) will 

accept applications to implement the coordinated regulatory process to exempt a subset of single-use 

disposable N95 filtering facepiece respirators (FFRs) from Food and Drug Administration (FDA)

premarket notification requirements. The N95 FFRs and data provided by the applicant must 

demonstrate:

• all applicable NIOSH N95 FFR requirements found in 42 CFR 84

• flammability, fluid resistance (penetration by synthetic blood), and biocompatibility, previously 

reviewed by the FDA, and evaluated by NIOSH in accordance with the Memorandum of 

Understanding (MOU) between the FDA/Center for Devices & Radiological Health and the Centers 

For Disease Control & Prevention/NIOSH/National Personal Protective Technology Laboratory

when FDA Threshold Criteria is not exceeded

• flammability, fluid resistance, and biocompatibility data provided to NIOSH must be generated by a 

laboratory meeting FDA’s Good Laboratory Practices requirement (21 CFR Part 58)

• no significant deviation from respirator designs previously cleared by the FDA under product code 

MSH, such as the addition of exhalation valves, novel head suspensions, sterility claims,

antimicrobial treatments, drug delivery systems, or nano scale technologies

• consideration of FDA recommendations for labeling medical products to inform users that the 

product is not made with natural rubber latex. 

Any device approved under this guidance will be labeled with the respiratory protection of “N95”, 

referred to as a Surgical N95, and will also be documented as meeting the FDA specified flammability, 

fluid resistance, and biocompatibility requirements and can be used in healthcare settings. Monthly 

Subject: Interim guidance regarding applications for NIOSH Approval of Filtering 

Facepiece Respirators in accordance with the Food and Drug Administration Final 

Order published May 17, 2018, and FDA/NIOSH MOU 225-18-006, dated November 

2017 (included as a reference in this notice)

Revised. Supersedes the November 2018 version
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NIOSH Certified Equipment List updates will include searchable information about approved Surgical 

N95 respirators.

• Surgical N95 respirator approval labels must include caution and limitation “S” defined as: 

Special or critical User Instructions and/or specific use limitations apply. Refer to User 

Instructions before donning. 

• The User Instructions and packaging must state the following under the “S – Special or Critical 

User Instructions” heading: This respirator has been approved as a NIOSH N95 filtering 

facepiece respirator, for use in healthcare settings, as a Surgical N95 Respirator conforming to 

recognized standards for biocompatibility, flammability, and fluid resistance. 

• The approval label is no longer required to have the caution and limitation “P” – NIOSH does 

not evaluate respirators for use as surgical masks.

• The abbreviated label (what is printed on every FFR) will include additional wording to inform 

users: “Surgical N95 Respirator”. See the example below. 

Four specific situations are noted:

• No immediate action under this guidance is required for an existing device that has previously 

obtained NIOSH approval and FDA 510(k) clearance (i.e., Surgical N95 FFRs). The existing 

approval will remain effective as long as the approval holder continues to 1) pay the annual 

NIOSH maintenance fee, 2) register and list your company with the FDA, and 3) meet NIOSH 

and FDA post market requirements. The approval holder will be expected to revise the User 

Instructions and packaging to include caution and limitation “S” and remove “P”, as defined 

above, the next time that the approval is submitted for an extension of approval. And in some 

cases, the approval holder must update the abbreviated label to align with this guidance. 

FFR Company Name

Model/Part Number

Surgical N95 

Respirator

TC-84A-0000

NIOSH

Lot #
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• If a manufacturer of an existing NIOSH-approved N95 FFR respirator has not previously sought 

FDA 510(k) clearance and now seeks to label a device with the additional protections 

(flammability, fluid resistance, and biocompatibility), the manufacturer must follow this 

guidance to achieve a NEW NIOSH approval for the Surgical N95 respirator. The approval 

holder is encouraged to issue a new model/part number for the Surgical N95. 

• If a manufacturer of an existing NIOSH-approved N95 FFR respirator has not previously sought 

FDA 510(k) clearance and does not seek to label this device with the additional protections 

(flammability, fluid resistance, and biocompatibility), the existing NIOSH approval will remain 

effective.

• If a manufacturer of a NEW N95 FFR seeks NIOSH approval for a Surgical N95, the manufacturer 

must follow this guidance. 

NEW NIOSH APPLICANTS:

If an applicant has never previously submitted any type of respiratory protective device for NIOSH 

approval, the applicant must first apply to NIOSH for a three-character Manufacturer’s Code by 

completing the Prospective Approval Holder Form and returning it to the NIOSH NPPTL Records Room. 

Applicants can obtain this form by contacting the NIOSH NPPTL Records Room at 

recordsroom@cdc.gov. After obtaining the Manufacturer’s Code, the manufacturer seeking approval 

for a Surgical N95 must follow this guidance. 

NEW APPLICANTS AND EXISTING NIOSH APPROVAL HOLDERS APPLYING for SURGICAL N95 

APPROVAL:

The applicant will use the NIOSH Standard Application Procedure (SAP) to complete the Standard 

Application Form. When completing the reason for application section (C.9), the applicant will indicate

they are using the consolidated process and seeking approval within the terms of the FDA Final 

Order (83 FR 22846) and the MOU. 

• The approval label provided as part of the NIOSH Surgical N95 application must include the 

caution and limitation “S” defined as: Special or critical User Instructions and/or specific use 

limitations apply. Refer to User Instructions before donning. The User Instructions and 

packaging (including all private label packaging) must state the following: This respirator has 

been approved as a NIOSH N95 filtering facepiece respirator, for use in healthcare settings, as 

a Surgical N95 Respirator conforming to recognized standards for biocompatibility, 

flammability, and fluid resistance. 
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• The abbreviated label (what is printed on every FFR) will include additional wording to inform

users: “Surgical N95 Respirator”. See the example below.

Applicants are required to provide documentation to NIOSH to indicate conformance to the FDA 

thresholds for flammability, fluid resistance, and biocompatibility, as described in the MOU. All data 

must be received in electronic formats as indicated in the NIOSH SAP. While NIOSH completes testing 

of hardware in accordance with 42 CFR 84 Subpart K, NIOSH is not conducting testing to verify the 

flammability, fluid resistance, or biocompatibility performance of the respirator as part of the 

consolidated Surgical N95 approval process. 

During the NIOSH document review process, NIOSH will review flammability, fluid resistance, and

biocompatibility test data and results provided by the applicant and in accordance with the Threshold 

Evaluation Criteria defined in the MOU. 

In accordance with the MOU, Surgical N95 Approval Holders are required to comply with the general 

controls required under the Federal Food, Drug, and Cosmetic Act (see section 513(a)(1) of the FD&C 

Act) and implementing regulations, including annual registration and listing obligations, quality system 

regulations, post market requirements, and other requirements as established by the FD&C Act and 

implementing regulations (e.g., requirements set forth in 21 CFR Parts 803 and 820) and applicable 

special controls under 21 CFR 878.4040. Nothing in this document changes or affects applicable FDA 

regulatory requirements or authority.

Manufacturers making claims exceeding the threshold evaluation criteria defined in the MOU must 

consider the timelines as described in the MOU. (MOU Appendix, Section 2). 

Note: Tuberculosis protection claims in accordance with CDC Guidance are allowed. 

FFR Company Name

Model/Part Number 

Surgical N95 

Respirator

TC-84A-0000 

NIOSH 

Lot #
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The NIOSH Surgical N95 Approval Holder must use NIOSH application procedures and notify NIOSH of 

any changes made to the NIOSH-Approved Surgical N95. Additional testing and data may be required 

before changes are approved by NIOSH. 

REFERENCES:

FDA Final Order

FDA Postmarket Requirements (Devices)

Approval of Respiratory Protective Devices, 42 C.F.R, Part 84

MOU 225-18-006 (also included below)
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Reference: MEMORANDUM OF UNDERSTANDING (MOU) 225-18-006), November 2017

BETWEEN THEFOOD&DRUGADMINISTRATION/CENTERFORDEVICES&RADIOLOGICAL HEALTH ANDTHE

CENTERSFORDISEASECONTROL&PREVENTION/NATIONALINSTITUTEFOR OCCUPATIONAL SAFETY & 

HEALTH/NATIONAL PERSONAL PROTECTIVE TECHNOLOGY LABORATORY

I. Purpose:

This Memorandum of Understanding (MOU) between the Food and Drug Administration (FDA), acting 

through its Center for Devices and Radiological Health (CDRH), and the Centers for Disease Control and 

Prevention (CDC), acting through its National Institute for Occupational Safety and Health (NIOSH), 

National Personal Protective Technology Laboratory (NPPTL) (herein referred to as “the Agencies”), 

provides a framework for coordination and collaboration between the Agencies relating to their 

regulation of Surgical N95 Respirators and N95 Filtering Facepiece Respirators (FFRs)1 used in 

healthcare settings (herein collectively referred to as “N95s”).1

A coordinated process will help to ensure that the various regulatory activities of each agency related 

to N95s are streamlined and harmonized when possible. The intent of this MOU is to help reduce 

conflicting and duplicative premarket processes for these devices so that stakeholders can easily and 

seamlessly discern what steps must be taken to satisfy the applicable regulatory requirements. 

Specifically, this MOU (1) describes the mechanisms by which specific information pertaining to N95s 

may be exchanged between the two Agencies and (2) provides a framework for efficient and 

coordinated regulatory oversight of N95s intended for use in healthcare settings. 

II. Definitions:

Definitions of specific terms used in this MOU are provided in this section. Also, please note that the 

respirators described in this section and throughout this MOU are designed to be used in the context 

of a comprehensive respiratory protection program as required by the Occupational Safety and Health 

Administration (OSHA) in 29 CFR 1910.134. 

Applicant: An individual, partnership, company, corporation, association, or other organization that 

designs, manufactures, assembles, or controls the assembly of a respirator and who seeks to obtain a 

certificate of approval [from NIOSH] for such respirator.2

Device: An instrument, apparatus, implement, machine, contrivance, implant, in vitro reagent, or 

other similar or related article, including any component, part, or accessory, which is:
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1. recognized in the official National Formulary, or the United States Pharmacopeia, or any

supplement to them,

2. intended for use in the diagnosis of disease or other conditions, or in the cure, mitigation,

treatment, or prevention of disease, in man or other animals, or

3. intended to affect the structure or any function of the body of man or other animals, and

4. which does not achieve its primary intended purposes through chemical action within or on

the body of man or other animals and which is not dependent upon being metabolized for the

achievement of its primary intended purposes. The term does not include software functions

excluded pursuant to section 520(o) of the Federal Food, Drug, and Cosmetic Act (FD&C Act)

(21 U.S.C. 360j(o)).3

Hazardous Atmosphere: Any atmosphere containing a toxic or disease producing gas, vapor, dust, 

fume, mist, or pesticide, either immediately or not immediately dangerous to life or health; or any 

oxygen-deficient atmosphere.4

Healthcare Personnel (HCP): All persons, paid and unpaid, working in healthcare settings who have 

the potential for exposure to patients and/or to infectious materials, including body substances, 

contaminated medical supplies and equipment, contaminated environmental surfaces, or 

contaminated air. HCP include, but are not limited to, physicians, nurses, nursing assistants, therapists, 

technicians, emergency medical service personnel, dental personnel, pharmacists, laboratory 

personnel, autopsy personnel, students and trainees, contractual personnel, home healthcare 

personnel, and persons not directly involved in patient care (e.g., clerical, dietary, house-keeping, 

laundry, security, maintenance, billing, chaplains, and volunteers) but potentially exposed to infectious 

agents that can be transmitted to and from HCP and patients.5

Healthcare Settings: Healthcare settings include, but are not limited to, acute-care hospitals; longterm care facilities, such as nursing homes and skilled nursing facilities; physicians' offices; urgent-care 

centers, outpatient clinics; and home healthcare. Examples of settings that are not included in this 

definition are schools and worksites. However, elements of this MOU may be applicable to specific 

sites within non-healthcare settings where care is routinely delivered (e.g., a medical clinic embedded 

within a workplace or school)).

Labeler: A “labeler” is any person who causes a label to be applied to a device, or who causes the label 

of a device to be replaced or modified, with the intent that the device will be commercially distributed 

without any subsequent replacement or modification of the label, except that the addition of the name 
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of, and contact information for, a person who distributes the device, without making any other 

changes to the label, is not a modification for the purposes of determining whether a person is a 

labeler7. 

Labeling: As defined in section 201(m) of the FD&C Act.

N95 Filtering Facepiece Respirator (FFR): Single-use, disposable half-mask respiratory protective 

device (RPD) that covers the user’s airway (nose and mouth) and offers protection from particulate 

materials at an N95 filtration efficiency level per 42 CFR 84.181. Such an N95 FFR used in a healthcare 

setting is a class II device, regulated by FDA under 21 CFR 878.4040 (FDA product code MSH). 

N95s: Includes N95 Filtering Facepiece Respirator (FFR) used in healthcare settings and Surgical N95 

Respirator. 

NIOSH Approval: Approval means a certificate or formal document issued by NIOSH stating that an 

individual respirator or combination of respirators has met the minimum requirements of 42 CFR Part 

84 and that the applicant is authorized to use and attach an approval label to any respirator, respirator 

container, or instruction card for any respirator manufactured or assembled in conformance with the 

plans and specifications upon which the approval was based, as evidence of such approval. 

Particulate Material: Solid or liquid particles found in the air. These particles may include dust, dirt, 

soot, smoke, and drops of liquid, and airborne particles transmitted to and from HCP and patients. 

Respiratory Protective Device (RPD): Any device designed to protect the user’s respiratory tract 

against the inhalation of a hazardous atmosphere.8 

Surgical N95 Respirator: Single-use, disposable respiratory protective device (RPD) used in a 

healthcare setting that is worn by HCP during procedures to protect both the patient and HCP from the 

transfer of microorganisms, body fluids, and particulate material at an N95 filtration efficiency level per 

42 CFR 84.181. A surgical N95 respirator is a class II device, regulated by FDA under 21 CFR 878.4040 

(FDA product code MSH).9

III. Background

FDA and NIOSH are sister Agencies within the Department of Health and Human Services (HHS). Both 

Agencies’ missions include protecting the public health. Both Agencies are authorized to regulate 

certain RPDs but have different statutory authorities and responsibilities.

The distinctions between NIOSH and FDA regulation of N95s may create confusion among 
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stakeholders. The collaboration outlined below, which is intended to streamline regulatory oversight 

of N95s used in healthcare settings, is expected to help ensure the availability of safe and effective 

products, particularly during times of increased demand.

The Agencies may update this MOU to include other RPDs utilized within the healthcare setting at a 

future date. However, note that any updates to the MOU will not automatically revise the conditions 

or limitations of exemption from 510(k).

We note that the MOU is drafted on the assumption that FDA has issued a notice in the Federal 

Register exempting certain N95s from 510(k) review (subject to applicable conditions and limitations of 

exemption, such as 21 CFR 878.9 and 21 CFR 878.4040(b)(1)). Generally, 21 CFR 878.4040(b)(1) 

exempts those N95s that (1) are determined not to exceed the threshold evaluation criteria and (2) 

have met the approval criteria and have NIOSH approval under its regulation. If such a notice is not 

finalized this MOU would not become effective (see section IX) or may need to be amended before 

becoming effective.

IV. Statutory Authorities

a. FDA:

The FD&C Act grants FDA authority to regulate devices, as defined in section 201(h) of the FD&C Act 

(21 U.S.C. 321(h)). FDA classifies devices into one of three regulatory classes – class I, II, or III – based 

on the level of control necessary to ensure the safety and effectiveness of the device. Class I devices 

are subject to the fewest regulatory controls and class III devices are subject to the most regulatory 

controls.

Generally, class II devices must receive premarket clearance from FDA under section 510(k) of the 

FD&C Act (21 U.S.C. 360(k)) before they can be legally marketed.10 FDA provides premarket clearance 

for devices that are "substantially equivalent"—as the term is defined in section 513(i)(1)(A) of the 

FD&C Act (21 U.S.C. 360c(i)(1)(A))—to a predicate device. In certain circumstances, FDA can exempt 

class II devices from these 510(k) requirements (see section 510(m) of the FD&C Act (21 U.S.C. 

360(m))). 

N95s are regulated by the FDA as class II devices under 21 CFR 878.4040 (FDA product code MSH). As 

of the effective date of this MOU (see section IX), N95s are exempt from 510(k) requirements (subject 

to applicable conditions and limitations to the exemption, such as those in 21 CFR 878.9 and 21 CFR 

878.4040(b)(1)). Generally, 21 CFR 878.4040(b)(1) exempts N95s if (1) they are determined not to 

exceed the threshold evaluation criteria and (2) have met the approval criteria and have NIOSH 

approval.
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b. NIOSH:

NIOSH is responsible for approval of RPDs intended for occupational use. The authority is granted to 

NIOSH in accordance with standards established in 42 CFR Part 84. NIOSH also addresses quality 

assurance requirements for the manufacturing of respiratory protective equipment.

Enforcement agencies, such as OSHA, require employers to provide NIOSH-approved respirators. In 

addition, private sector certification scheme owners such as the National Fire Protection Association 

use the NIOSH approval as the basis for their certification.

V. Scope:

This MOU applies to N95s used in healthcare settings, which protect both the patient and HCP from 

the transfer of microorganisms, body fluids, and particulate material.11

Future iterations of this MOU may extend this scope to other RPDs utilized in a healthcare setting 

based on concurrence between the Agencies. However, note that any updates to the MOU will not 

revise the conditions or limitations to the exemption for 510(k) as identified in the Federal Register 

Notice.

VI. Roles and Responsibilities:

Under this MOU, the Agencies agree to the following roles and responsibilities:

• The Agencies agree to share relevant information pertaining to N95s with each other, while

ensuring that the exchange of such information complies with applicable law (see section VII).

• The Agencies agree that N95s that are intended to be worn in healthcare settings to protect

against the transfer of microorganisms, body fluids, and particulate material are devices under

the FD&C Act and subject to regulatory oversight by FDA. Currently, N95s are class II devices.

• The Agencies agree to the following framework for NIOSH and FDA review of N95s that are

intended to be used in healthcare settings (details on this framework, including the Agencies’

mutually agreed upon threshold evaluation and NIOSH approval criteria, are included in the

Appendix):

o NIOSH first will evaluate whether applicants’ devices exceed the threshold evaluation

criteria and make a recommendation.
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o For devices that do not exceed the threshold evaluation criteria, NIOSH will evaluate

whether applicants’ devices meet the approval criteria. NIOSH will update its Respirator

Approval Program to reflect the approval criteria. Devices that subsequently meet the

approval criteria will be approved by NIOSH. As noted above, such NIOSH-approved

devices are exempt from FDA’s 510(k) requirements subject to applicable conditions

and limitations to the exemption.

o For devices that exceed the threshold evaluation criteria and/or exceed the conditions

and limitations of the exemption, FDA will review 510(k)s submitted to the Agency. In

its review, FDA will consider information provided to FDA from NIOSH regarding

whether applicants’ devices meet the approval criteria. This will allow FDA to focus on

other relevant aspects of the device in its substantial equivalence review.

• The Agencies agree that while NIOSH makes a recommendation regarding whether an applicant’s

device exceeds the threshold evaluation criteria, this recommendation does not change any

requirements of a device manufacturer under the FD&C Act. This includes general controls under the

FD&C Act and the requirement for manufacturers to assess whether their device exceeds the

conditions and limitations of exemption as identified in 21 CFR878.9 and 21 CFR 878.4040(b)(1).

• The Agencies agree that NIOSH may hire certified third party test laboratories to conduct performance

testing and may leverage the performance evaluation of those laboratories in its approval.

• The Agencies agree to update, as appropriate, the threshold evaluation and approval

criteria. Appropriate procedures, which follow notice and comment, will be followed for any updates

that affect the 510(k) exemption.

• The Agencies agree to utilize their existing post market and surveillance authorities:

o N95s will continue to be subject to post market and other requirements as established

by the FD&C Act and implementing regulations (e.g., requirements set forth in 21 CFR

Parts 803 and 820).

o NIOSH will utilize post market and surveillance authorities set forth in 42 CFR Part 84.

• The Agencies agree that this MOU does not affect registration and listing obligations under section 510

of the FD&C Act (21 U.S.C. 360).
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• The Agencies will ensure that their databases identifying registered establishments and any associated

N95s are reconciled on a pre-determined schedule to ensure that consistent information is being

conveyed to the user community.

• N95 labelers will continue to be subject to FDA’s requirements for Unique Device Identification.12

• The Agencies have defined approval criteria based on standards for effective performance, reliability,

and quality of N95s.

• The Agencies agree to identify and assign staff and other resources (e.g., laboratories) as needed to

complete N95 assessment.

VII. Information Sharing:

1. FDA and CDC recognize and agree that information exchanged under this MOU that contains any of

the following types of information must be protected from unauthorized use and disclosure: (1)

confidential commercial information, such as the information that would be protected from public

disclosure pursuant to Exemption 4 of the Freedom of Information Act (FOIA); (2) personal privacy

information, such as the information that would be protected from public disclosure pursuant to

Exemption 6 or 7(C) of the FOIA; or (3) information that is otherwise protected from public disclosure

by Federal statutes and their implementing regulations (e.g., Trade Secrets Act (18 U.S.C. 1905)), the

Privacy Act (5 U.S.C. 552a), other FOIA exemptions not mentioned above (5 U.S.C. 552(b)), the FD&C

Act (21 U.S.C. 301 et seq.), the Health Insurance Portability and Accountability Act (HIPAA), Pub. L. 104-

191), Section 319L(e) of the PHS Act (42 U.S.C. 247d-7e(e)), and disclosure restrictions subject to 41

U.S.C. 2101-2107 (Procurement Integrity Act) and 48 CFR 3.104 (Federal Acquisition Regulation).

2. Both parties will establish safeguards to ensure that any nonpublic information shared under this

MOU is protected from unauthorized disclosure or use. Those safeguards should include the marking

of any confidential materials as “confidential” prior to disclosure to the other party or the use of

encryption technologies when appropriate. Information consisting of confidential commercial

information or trade secrets may be shared pursuant to the procedures set forth in the Memorandum

of Understanding Between FDA and CDC, which describes information sharing procedures between

FDA and CDC (FDA MOU No. 225-24-0017, available at

http://www.fda.gov/aboutfda/partnershipscollaborations/memorandaofunderstandingmous/domesti

cmous/ucm402130.htm).

3. Each agency agrees to promptly notify the other of any actual or suspected unauthorized disclosure

of information shared under this MOU.
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4. If records provided by either party under this agreement are the subject of a FOIA request submitted

to the party that received the records, that party will refer the FOIA request and relevant records to

the party that provided the records for processing. If the FOIA request seeks both parties’ records or if

the request is for records created by one party that incorporates information provided by the other

party, in accordance with the HHS FOIA regulations at 45 CFR pt. 5, the party receiving the FOIA

request will forward all such requests to the respective FOIA offices for disposition.

VIII. Fees:

This MOU does not affect fees assessed by NIOSH and FDA in alignment with their current fee 

structure. N95s that are exempt from 510(k) requirements are not subject to the medical device user 

fees associated with submission of a 510(k) (i.e., fees under section 738(a)(2)(A)(viii) of the FD&C Act 

(21 U.S.C. 379j(a)(2)(A)(viii))). 

IX. Relevant Dates:

• This MOU shall be effective upon FDA’s publishing an order in the Federal Register that sets forth a

final determination that N95s are exempt from 510(k) requirements (subject to applicable conditions

and limitations to the exemption, as identified in 21 CFR 878.9 and 21 CFR 878.4040(b)(1)). Generally,

21 CFR 878.4040(b)(1) exempts N95s if they (1) are determined not to exceed the threshold evaluation

criteria and (2) have met the approval criteria and have NIOSH approval under its regulation.

• The MOU will continue to be in effect until canceled in writing by either of the Agencies with adequate

notice no less than 180 calendar days.

X. Miscellaneous:

Conflicts that arise relating to the MOU after the MOU is in effect will be resolved by CDRH and NIOSH 

NPPTL Points of Contact (see section XI). If conflicts cannot be resolved at this level, then the 

signatory authorities for this MOU will resolve the conflicts either by coming to informal agreement or 

by amending the MOU. 

• This MOU may be amended in writing at any time by mutual agreement of the parties.

• This MOU will be reviewed annually by the Points of Contact to determine if any mutually agreed upon

changes or amendments should be made to the MOU. Any such changes or amendments will be

formally incorporated in the MOU after adequate procedures for amending the 510(k) exemption have

been followed.
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XI. Points of Contact:

Director, National Personal Protective Technology Laboratory (NPPTL)

National Institute for Occupational Safety and Health

Centers for Disease Control and Prevention

Pittsburgh, PA

Director, Emergency Preparedness/Operations and Medical Countermeasures

Center for Devices and Radiological Health

Food and Drug Administration

Silver Spring, MD

Appendix: NIOSH and FDA Review Processes for N95s 

Section 1. Review Process:

1. Review Processes for N95s: NIOSH and FDA review processes for N95s consist of the following steps

(also see Figure 1):

 Applicant submission to NIOSH. Submission must include design documentation, performance

(pre-test) data, and information on an applicant’s quality assurance program per 42 CFR Part

84.

 Threshold Evaluation Review by NIOSH. During the threshold evaluation review, NIOSH utilizes

the criteria that the Agencies have agreed upon (see Appendix Section 2 for specific

criteria). NIOSH plans to perform this review, and make a recommendation to FDA regarding

whether a device exceeds the threshold evaluation criteria, within 10 working days of receipt of

the applicant’s submission. FDA will make a final determination as to whether a device exceeds

the threshold evaluation criteria and communicate that determination to NIOSH within 10

working days.

 Review for N95s that Do Not Exceed the Threshold Evaluation Criteria.

o NIOSH Approval Review. NIOSH will strive to complete its approval review of these

devices within 90 calendar days of receiving the submission. NIOSH determines

whether the N95 receives approval based on pass/fail criteria for performance testing

and the assessment of the other components of the submission (see Appendix Section 3

for specific criteria). NIOSH will notify FDA of its decision to approve (or not approve)

the N95.
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o FDA Consult. Throughout the threshold evaluation and approval reviews, NIOSH may

request a consult from FDA regarding general questions as well as for assistance in

determining whether the threshold evaluation and/or approval criteria are met. FDA

plans to respond to consult requests from NIOSH as soon as possible, and within 10

working days of receipt when they relate to the approval review, to enable NIOSH to

meet its 90-calendar-day review goal.

 Review for N95s that Exceed the Threshold Evaluation Criteria.

o FDA 510(k) Review. For such devices, in accordance with section VII of this MOU on

information sharing, FDA plans to notify NIOSH of all 510(k)s submitted within 10

working days of receipt of the 510(k). Within 30 calendar days of receipt, FDA will also

notify NIOSH as to whether the 510(k) warrants the review of clinical data FDA will strive

to complete its 510(k) review within 60 calendar days of receiving the

submission. NIOSH continues its approval review and in its 510(k) review, FDA will

consider information provided to FDA from NIOSH regarding whether the device meets

the Agencies’ mutually agreed upon approval criteria (see Appendix Section 3 for

specific criteria), which will allow FDA to focus on other relevant aspects of the device in

its substantial equivalence review. Examples of other relevant aspects of device

performance may include but are not limited to bacterial/viral filtration efficiency,

additional biocompatibility evaluations such as gas pathway safety assessments,

toxicology, etc.
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NIOSH Approval Review. NIOSH will perform its approval review of these N95s using the mutually 

agreed upon approval criteria (see Appendix Section 3 for specific criteria) and share information from 

this review with FDA such that it can be considered in FDA’s 510(k) review.

Figure 1. N95 Review Processes Flowchart

* NIOSH makes a recommendation regarding whether an applicant’s device exceeds the

threshold evaluation criteria, this recommendation does not change any requirements of a device

manufacturer under the FD&C Act. This includes general controls under the FD&C Act and the

requirement for manufacturers to assess whether their device exceeds the conditions and

limitations of exemption as identified in 21 CFR 878.4040(b)(1) and 878.9.

**Refer to Appendix Section 2 for threshold evaluation criteria
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Section 2. Threshold Evaluation Criteria:

2. Threshold Evaluation Criteria: An N95 EXCEEDS the threshold evaluation criteria (and thus would

likely not be exempt from 510(k) requirements even if subsequently approved by NIOSH), if:

 The N95 is intended for any of the following intended uses or it is labeled or otherwise

represented (e.g., the instructions for use) for:

o Specific disease and/or infection prevention (including, but not limited to, protection against

Methicillin-resistant Staphylococcus aureus (MRSA), Haemophilus influenzae, or H1N1)

o Viral or bacterial filtration performance (e.g., filters 95% of bacteria)

o Antimicrobial (antiviral/antibacterial) function

o Hypoallergenicity (e.g., for users with sensitive skin)

o Filtration of surgical smoke or plumes

OR

 The N95 contains technologies including, but not limited to:

o Antimicrobial coatings

o Coatings intended to modify the performance of the product that are not related to the

product’s respiratory protection characteristics

o Drug delivery systems

o Products that contain nanoscale technologies such as particles, fibers, wires, tubes, selfassembly products on a nanoscale (e.g., an antimicrobial coating)

o The combination of an N95 with another FDA-regulated product.
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Section 3. NIOSH Approval Criteria:

5. Approval Criteria: NIOSH will assess the performance of the N95 with respect to differential

pressure, particulate filtration efficiency (PFE), exhalation valve leakage, biocompatibility,

flammability, and fluid resistance. The evaluation of flammability, fluid resistance, and

biocompatibility on the final finished N95 will be new assessments for NIOSH; they have

historically been a part of FDA’s premarket evaluation only.

The mutually agreed upon approval criteria are described in greater detail below. An N95

intended to be used in healthcare settings will be evaluated for the following approval criteria:

 Differential pressure: NIOSH requirement as indicated in 42 CFR 84.180. The N95s must be

evaluated using the appropriate NIOSH standard test procedures (STPs) and meet the evaluation

criteria specified in 84.180.

 Particulate filtration efficiency: NIOSH requirement as indicated in 42 CFR 84.181. The N95s must

be evaluated using the appropriate NIOSH STPs and meet the evaluation criteria specified in

84.181.

 Exhalation valve leakage: NIOSH requirement as indicated in 42 CFR 84.182. The N95s must be

evaluated using the appropriate NIOSH STPs and meet the evaluation criteria specified in 84.182.

 Biocompatibility (new): Appropriate analysis and testing (such as that outlined in the ISO-10993-1

standard, “Biological Evaluation of Medical Devices Part 1: Evaluation and Testing within a Risk

Management Process.”)13 must demonstrate the biocompatibility of N95s. Tests selected must be

appropriate for duration and level of contact with the device (e.g., limited contact devices

including skin). N95s will be tested on a pass/fail basis with respect to cytotoxicity, sensitization,

and irritation. In general, N95s are made of melt blown/spun bound polypropylene layers. NIOSH

will consult with FDA regarding any materials that have not been used in N95s previously. For

example, the use of different materials may result in the need to include additional

biocompatibility evaluations such as gas pathway safety assessments of any leachates coming

from the final finished N95.

 Flammability (new): Flammability is met if any of the standards and test methods identified

below is utilized in the evaluation of flammability by class, and the material is determined to be

National Fire Protection Association (NFPA) class I or II. N95s comprised of NFPA class I and class

II flammability materials are recommended. Devices with a NFPA class 3 rating should have a

flammability warning. Devices with a NFPA class 4 rating will be considered to have failed this

criterion because such devices are not appropriate for use in the operating room.
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o CPSC CS-191-53 Flammability Test Method (16 CFR Part 1610)

o Standard for Flammability of Clothing Textiles NFPA Standard 702-1980

o Standard for Classification of Flammability of Wearing Apparel UL 2154

 Fluid resistance (new): Fluid resistance is met if the N95 passes the test method below, or

comparable test method, at any specific velocity as identified in the labeling. N95s are tested on a

pass/fail basis at specified velocities.

o ASTM F 1862: Standard Test Method for Resistance of Surgical Mask to Penetration by

Synthetic Blood

Approved and Accepted

CDC/NIOSH

Maryann D’Alessandro, Ph. D 

Director

National Personal Protective Technology Laboratory

November 2017 

Approved and Accepted

FDA

Jeffrey Shuren, M.D., J. D 

Director

Center for Devices and Radiological Health

November 2017

1. NIOSH has regulatory authority over several categories of FFRs. This MOU is only focused on one of

these categories, the N95 FFR used in healthcare settings.

2. This is the same as the definition of “applicant” in 42 CFR 84.2.

3. This is the same as the definition of “device” in section 201(h) of the FD&C Act (21 U.S.C. 321(h)).

4. This is the same as the definition of “hazardous atmosphere” in 42 CFR 84.2.

5. This definition is the same as the 2008 Department of Health and Human Services (HHS) definition of

HCP, which was adopted by CDC in its guidance on Prevention Strategies for Seasonal Influenza in

Healthcare Settings

(see http://www.cdc.gov/flu/professionals/infectioncontrol/healthcaresettings.htm).

6. This is the same definition as that adopted by CDC in its guidance on Prevention Strategies for

Seasonal Influenza in Healthcare Settings

(see http://www.cdc.gov/flu/professionals/infectioncontrol/healthcaresettings.htm).

7. Note this is an FDA definition. See 21 CFR 801.3.[0]
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8. This is very similar to the definition of “respirator” in 42 CFR 84.2.

9. This definition does not include other respirators, including those regulated under 21 CFR 878.4040

(FDA product code ONT) and those regulated under 21 CFR 880.6260 (FDA product codes NZJ and

ORW).

10. Devices legally in commercial distribution before May 28, 1976 are “grandfathered” and do not

require 510(k) clearance unless the device has been significantly modified or there has been a change

in intended use. At the time of the publication of this MOU, neither FDA nor NIOSH is aware of any

marketed N95s that were in distribution before May 28, 1976.

11. See 21 CFR 878.4040 (FDA product code MSH).

12. Information on Unique Device Identification, including applicable requirements and compliance

dates, is located at the following web address:

http://www.fda.gov/MedicalDevices/DeviceRegulationandGuidance/UniqueDeviceIdentification/.

13. Note that FDA has recognized this complete standard with a few exceptions. See FDA’s Recognized

Consensus Standards database for a list of exceptions, available at:

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfStandards/search.cfm.

 Revision (R) Date

Reason for 

Revision

1.0 14 August 2020

NIOSH revised this notice to remove references to “N95-F” 

filtering facepiece respirators. On June 29,2020 FDA and NIOSH 

agreed to use existing terminology “Surgical N95” to define 

these FFRs approved before and after the 2018 MOU.