PPE CASE

Personal Protective Equipment Conformity Assessment Studies and Evaluations

Filtration Efficiency Performance of Non-NIOSH-Approved 

International Respiratory Protective Devices: Phase Two

National Institute for Occupational Safety and Health (NIOSH) 

National Personal Protective Technology Laboratory (NPPTL) 

This report summarizes the filtration performance results from the assessments that took place as a 

result of an Emergency Use Authorization (EUA) issued by the United States Food and Drug 

Administration (FDA)1 and discusses important considerations when 

purchasing non-NIOSH-approved international respiratory protective 

devices temporarily authorized for occupational use in the United States. 

In order to supplement the national inventory of N95 filtering facepiece 

respirators (FFRs) and increase the supply of available respirators, the 

National Institute for Occupational Safety and Health (NIOSH), part of the 

Centers for Disease Control and Prevention (CDC), suggested several

strategies to optimize the supply of N95 respirators (CDC 2020). These

guidelines include strategies for crisis capacity—those used when there is 

a shortage of NIOSH-approved respirators. Included within this set of 

strategies is the provision for the use of non-NIOSH-approved 

international respiratory protective devices that were manufactured 

under foreign standards but that incorporate performance requirements 

similar to NIOSH-approved N95 FFRs.

2

Consistent with these guidelines, in March 2020, FDA issued an EUA permitting the use of specified 

international respirators from seven countries (FDA 2020). The United States Occupational Safety and 

1 The initial EUA issued by FDA was in effect from March 24, of 2020, through May 6, 2020. A revised EUA was issued by 

FDA on May 7, 2020, reducing the number of personal respiratory devices included as approved under the EUA (FDA 2020). 2 NIOSH-approved N95 FFRs filter out at least 95% of particulate matter. The strategy to supplement the supply of NIOSHapproved N95 FFRs by temporarily allowing for the emergency use of FFRs manufactured under foreign standards includes 

an expectation of similar filtration efficiency. 

NIOSH evaluations show 

that 26% of non-NIOSHapproved international 

respiratory protective 

devices have inconsistent 

filtration performance and 

60% of assessments found

filtration efficiencies less 

than 95%. The NIOSHapproved N95 filtering 

facepiece respirator 

standard is 95%.
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Health Administration (OSHA) issued provisions to permit FFRs approved in these select countries to be 

temporarily used in the workplace (OSHA 2020). 

While these international respiratory protective devices included in FDA’s EUA and OSHA’s 

enforcement guidelines have similar performance requirements compared with NIOSH-approved 

devices, NIOSH does not oversee the initial production, regulate sustained manufacturer quality 

control for these products, monitor post-market quality, or have knowledge about the product’s 

handling and exposures after leaving the manufacturer’s control. Due to the potential to have these 

non-NIOSH-approved international respiratory protective devices used by workers in the United 

States, NIOSH designed a process to assess the particulate filtration performance. The goal of the

assessment was to provide consumers of personal respiratory protection devices and other interested 

parties a point-of-use quantitative assessment of the devices temporarily authorized for use.

As reported in the Phase One PPE CASE report (NPPTL Report Number P2020-0112), NIOSH completed 

105 assessments of non-NIOSH-approved international respiratory protective devices from the start of 

the FDA EUA April 10, 2020 through May 6, 2020. This PPE CASE report (Phase Two) provides the 

results of 251 NIOSH assessments of non-NIOSH-approved international respiratory protective devices 

conducted from May 7 through August 17, 2020.

How NIOSH Assessed Non-NIOSH-Approved International 

Respiratory Protective Devices

• To address concerns regarding non-NIOSH-approved international respiratory protective 

devices, NIOSH developed a protocol to quickly evaluate the filtration efficiency performance of 

these devices. To allow for a smaller sample size and quicker turn-around time, the samples 

were tested using a modified version of NIOSH Standard Test Procedure TEB-APR-STP-0059.

• NIOSH received requests via formal process to evaluate non-NIOSH-approved international 

respiratory protective devices included on the FDA’s EUA. Qualifying requests included those 

received from federal, state, and local government agencies; healthcare providers; employers 

in non-healthcare industries; public safety and first responder organizations; and universities. 

Requests received directly from a manufacturer, distributor, importer, or supplier were outside 

of the scope of this evaluation process. Requests also had to include all specified information 

on the request form, including, for example, the manufacturer name, the model number, and 

the performance standard under which the device was manufactured.

• Through the packaging and labeling, NIOSH recorded the standard to which the samples 

provided claimed conformance. 

• The sampling protocol used to provide the devices to NIOSH was at the discretion of the 

outside user group making the request, however NIOSH required each requestor to submit a 

minimum of 10 devices per model for evaluation. 
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Findings

Sample Characteristics

• NIOSH completed 251 assessments of non-NIOSH-approved international respiratory protective 

devices following FDA’s May 7, 2020, revision of its March 24, 2020, EUA.

o Information regarding the manufacturer, model, and performance standard came from 

the packaging and the labels included with or on the assessed device. 

o Some samples received did not indicate the international performance standard to 

which the product conformed. In those cases, NIOSH classified the performance 

standard as “Unknown.”

o Assessments were completed on international respiratory protection devices that were 

largely distinct in terms of the sample of personal respiratory devices assessed; there

were 170 distinct manufacturers and 177 distinct models. 

• NIOSH completed assessments at the request of federal government agencies (47%), employers 

in non-healthcare industries (27%), state governments (12%), healthcare providers (9%), local 

governments (3%), individuals and organizations not classified (1%), and public safety and first 

responder organizations (1%).

• Of these assessments, approximately 95% of the respiratory devices used an ear loop design to 

secure the mask to the wearer’s face; the others used a head strap design (5%).

Overall Results

• For each of the 251 requests, NIOSH evaluated the filtration efficiency for each individual unit

and recorded the maximum and the minimum filtration efficiency observed and then 

determined whether 1) all individual units within the assessment tested above 95% efficiency; 

2) all individual units within the assessment tested below 95% efficiency; or 3) there was a 

mixture of units, with some testing above 95% and some testing below 95%. 

o In 104 of the assessments (approximately 41%), all individual units tested above 95% 

particulate filtration efficiency. In 82 of the assessments (approximately 33%), all 

individual units tested below 95%. In the remaining 65 assessments (26%), there was a 

mix of units that tested above and below 95%. See Figure 1. 
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Figure 1: Overall Filtration Efficiency Results

Results by International Standard

• Table 1 presents filtration results by international standard. It shows the numbers and relative 

percentages of assessments that were categorized as all units above 95%, all units below 95%, 

and a mix of units above and below 95% by international standard.

o Highest Performing Filtration Efficiency International Respirators Assessed. All units 

from 9 of 10 assessments (90%) conducted on devices that claimed conformance with 

GB19083-2010 (an international standard originating from China) tested above 95%. All 

units from one of the two assessments (50.0%) conducted on devices that claimed 

conformance with KMOEL-2017-64 (an international standard originating from Korea)

tested above 95%. 

o Lowest Performing Filtration Efficiency International Respirators Assessed. All units 

from the 1 of 1 assessment (100%) conducted on devices that claimed conformance 

with GB/T 32610-2016 (an international standard originating from China) tested below 

95%. All units from 7 of 17 assessments (78%) that claimed conformance with EN149-

2001 (an international standard originating from Europe) tested below 95%. All units 

from 22 of 39 assessments (56%) that claimed to conform with both EN149-2001 and 

GB2626-2006 (international standards originating in Europe and China, respectively) 

tested below 95%. 
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Table 1: Summary Filtration Results by International Standard Claimed

Standard NIOSH/NPPTL Assessment Results Number of 

Assessments 

Approximate 

Percentage

of 

Assessments 

for Each 

Standard

Europe EN149-2001 All above 95% 6 35%

All below 95% 7 41%

Some above and some below 95% 4 24%

Europe/China EN149-2001 & 

GB2626-2006

All above 95% 9 23%

All below 95% 22 56%

Some above and some below 95% 8 21%

China GB/T 32610-2016 All above 95% 0 0%

All below 95% 1 100%

Some above and some below 95% 0 0%

China GB19083-2010 All above 95% 9 90%

All below 95% 0 0%

Some above and some below 95% 1 10%

China GB2626-2006 All above 95% 77 44%

All below 95% 50 29%

Some above and some below 95% 48 27%

Korea KMOEL-2017-64 All above 95% 1 50%

All below 95% 0 0%

Some above and some below 95% 1 50%

Unknown All above 95% 2 29%

All below 95% 2 29%

Some above and some below 95% 3 42%

Variability Within Individual Assessments

• When facing respiratory hazards in the workplace, end users must be able to trust that 

individual respirator units, which are labeled and packaged identically, provide a consistent 

level of performance. (See 42 CFR Part 84 for explanation of quality requirements NIOSHapproved respirators, where a consistent unit-to-unit filtration efficiency is required.)

• In this context, an assessment of filtration efficiency variation through an analysis of the range 

within individual assessments is important because the range indicates the level of filtration 

performance consistency that can be expected from one unit to the next when the units are 

labeled and packaged consistently.

• As noted previously, each individual assessment tested at least 10 different units submitted 

with the same label and packaging. There were 251 assessments conducted. 
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• For each individual assessment, NIOSH calculated the range in the filtration efficiencies of the 

units by subtracting the lowest observed filtration efficiency from the highest observed 

filtration efficiency. This range provides an indication of how consistent the unit-to-unit 

filtration properties were within each individual assessment.

o For example, in a single assessment, if the highest filtration recorded was 95% and the 

lowest was 30%, the range would equal 65% (95 minus 30). With a range such as this,

the end user could not have confidence in the consistency of the level of protection. 

• Approximate quartiles within the 251 assessments suggested that

o 67 (27%) had a greater than 15% range in filtration efficiencies

o 54 (21%) had a 5%–15% range in filtration efficiencies

o 77 (31%) had a 1%–5% range in filtration efficiencies

o 53 (21%) had a 0%–1% range in filtration efficiencies

• Table 2 reports the highest and lowest ranges observed among assessments based on the 

reported international standard. 

o Across the 251 assessments, the lowest range in filtration results was 0.06%,

corresponding to a sample of 30 units from a non-NIOSH-approved respirator that 

claimed conformance with China standard GB2626-2006; the maximum filtration 

observed was 100% and the minimum was 99.94%. 

o Across the 251 assessments, the highest range in filtration results was 86.75%,

corresponding to a sample of 10 units that claimed to conform with both EN149-2001 

and GB2626-2006, standards originating from Europe and China respectively; the 

maximum filtration observed was 92.05% and the minimum was 5.30%. 

Table 2: Highest and Lowest Range in Filtration Efficiency Performance Within Assessments by 

International Standard Claimed

Standard Lowest Range in Filtration 

Efficiency (%)

Highest Range in Filtration 

Efficiency (%) Number of Assessments

Europe EN149-2001 0.18 78.00 17

Europe/China EN149-2001 & 

GB2626-2006 0.13 86.75 39

China GB/T 32610-2016 30.80 30.80 1

China GB19083-2010 0.26 5.46 10

China GB2626-2006 0.06 71.50 175

Korea KMOEL-2017-64 0.09 6.93 2

Unknown 0.40 67.42 7

Overall 0.06 86.75 251

NOTE: The values reported in the table reflect the range of filtration efficiency observed within each assessment. Lower 

values represent lower filtration efficiency variability while higher values represent higher filtration efficiency variability. 
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Conclusion 

The results of these assessments suggest that there was considerable range in filtration efficiency for 

most of the models assessed. Further, in 33% of the assessments, all units tested below 95%. 

During Phase One of NIOSH’s international assessments, NIOSH primarily assessed international 

respiratory devices that were included in FDA’s March 27, 2020 EUA. Based in part on these results 

(reported in NPPTL Report Number P2020-0112), on May 7, 2020, FDA removed 57 respirators from its

International EUA list (FDA 2020). Approximately half (47%) of NIOSH assessments completed during 

Phase Two were performed at the request of federal agencies continually investigating the efficiency of 

incoming non-NIOSH-approved international respiratory protective devices and the possibility of 

continually revising the FDA EUA. 

While filtration efficiency shows how well the filter media performs, users must ensure a proper fit is 

achieved. This assessment procedure provides useful information about the filtration efficiency of 

respiratory protection devices that may be used by workers in national emergency situations; however, 

it is not equivalent to the standard test procedure used to evaluate NIOSH-approved N95 respirators. 

Therefore, the values reported on the international assessment results – not NIOSH-approved

webpage only provide an indication of filtration efficiency and confirm neither that the product 

performs equivalently to a NIOSH-approved N95 nor that it conforms with the standard requirements 

claimed by the manufacturer.

International Respiratory Protective Device Assessment: Phases

One and Two Summary and Comparison

As noted in the Phase One PPE CASE report (NPPTL Report Number P2020-0112), NIOSH completed 

105 assessments of non-NIOSH-approved international respiratory protective devices between the 

start of the FDA EUA and May 6, 2020. The current PPE CASE report (Phase Two) summarized 251 

NIOSH assessments conducted from May 7, 2020, through August 17, 2020.

Figure 2 shows a side-by-side comparison of the results between Phase One and Two. Table 3 

summarizes the number of assessments that fell into each filtration efficiency category.
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Figure 2: Side-by-Side Summary and Comparison of Phase One and Phase Two Results

Table 3: Phase One and Phase Two Comparison and Summary

Phase One Phase Two Comparison Phases One and 

Two Combined

All units tested were above 95% 33% (35) 41% (104) 8% Increase 39% (139)

All units tested were below 95% 40% (42) 33% (82) 7% Decrease 35% (124)

Some units above and some below 95% 27% (28) 26% (65) 1% Decrease 26% (93)

Total number of assessments 105 251 356

As shown in Figure 2 and Table 3, an 8% increase was observed for the category of assessments in 

which each unit tested above 95% filtration efficiency. There was also a 7% decrease for the category 

of assessments in which each unit tested below 95% filtration efficiency. These changes may have 

resulted, in part, from the awareness raised by the NIOSH assessments in Phase One and the 

transparent and timely information-sharing of assessment results between FDA and NIOSH. 

Table 3 also shows the results of the assessments when Phase One and Two are combined (Number of 

Assessments = 356). In total, in 39% of the assessments (n=139) all units tested above 95% filtration 

efficiency, in 35% of the assessments (n=124) all units tested below 95% filtration efficiency, and in 

26% of the assessments (n=93) some units tested above and some tested below 95% filtration 

efficiency. These summary statistics suggest that the level and consistency of filtration efficiency of the 

international respiratory protection devices assessed remain concerning. 
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What the User/Purchaser Can Do When Purchasing Non-NIOSHApproved International Respiratory Protective Devices 

• Healthcare organizations should review the FDA EUAs before purchasing any non-NIOSHapproved international respiratory protective devices.

• Purchasers should review the NIOSH Respirator Assessment Results webpage before purchasing 

respirators that claim to meet the standards identified in Table 1.

• Purchasers should refer to the following guidance to evaluate respirators from other countries 

to determine whether they are counterfeit or provide substandard protection: Factors to 

Consider When Planning to Purchase Respirators from Another Country, Including KN95 

Respirators from China and Understanding the Use of Imported Non-NIOSH-Approved 

Respirators.
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Get More Information 

For more information related to personal protective equipment, visit the NIOSH website.

Find NIOSH products and get answers to workplace safety and health questions: 

1-800-CDC-INFO (1-800-232-4636) | TTY: 1-888-232-6348 

CDC/NIOSH INFO: cdc.gov/info | cdc.gov/niosh/npptl

Monthly NIOSH eNews: cdc.gov/niosh/eNews

Disclaimer 

Mention of any company or product does not constitute endorsement by the National Institute for Occupational Safety and 

Health (NIOSH). In addition, citations to websites external to NIOSH do not constitute NIOSH endorsement of the 

sponsoring organizations or their programs or products. Furthermore, NIOSH is not responsible for the content of these 

websites. All web addresses referenced in this document were accessible as of the publication date. 

Suggested Citation

NIOSH [2020] PPE CASE: Filtration efficiency performance of non-NIOSH-approved international respiratory protective 

devices: phase two. Andrews A, Powers J, Cichowicz J, Coffey C, Fries ML, Yorio PL, D’Alessandro M. Pittsburgh, PA: U.S. 

Department of Health and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational 

Safety and Health, NPPTL Report Number P2020-0113.