PPE CASE

Personal Protective Equipment Conformity Assessment Studies and Evaluations

Filtration Efficiency Performance of Non-NIOSH-Approved 

International Respiratory Protective Devices: Phase One

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 the initial 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 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 the 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 the FDA was in effect from March 24, of 2020 to May 6, 2020. A revised EUA was issued by the 

FDA on May 7, 2020 reducing the number of personal respiratory devices included (FDA 2020). 

2 NIOSH approved N95 FFRs filter out at least 95% of particulate matter. The strategy to supplement 

the supply of NIOSH-approved 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 many non-NIOSHapproved international 

respiratory protective 

devices have inconsistent 

filtration performance and 

most assessments resulted 

in filtration efficiencies less 

than 95% 
Health Administration (OSHA) issued provisions to permit FFRs approved in these select foreign 

countries to be temporarily used in the workplace (OSHA 2020). 

While these international respiratory protective devices included in the 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 respirators 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 and other interested parties a point-of-use quantitative assessment of 

the devices temporarily authorized for use.

How NIOSH Assessed Non-NIOSH-Approved International 

Respiratory Protective Devices

• To address concerns regarding N95 alternative respirators, 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 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, model number, and the performance 

standard under which it 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. 
Findings

Sample Characteristics

• As of May 6, 2020, NIOSH completed 105 assessments of non-NIOSH approved international 

respiratory protective devices. 

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

the packaging and the labels included with or on the assessed international respiratory 

protection device. 

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

which the product conformed. In these 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 87 distinct manufacturers and 102 distinct models. 

• NIOSH completed assessments at the request of state governments (29%), healthcare providers 

(24%), employers in non-healthcare industries (21%), public safety and first responder 

organizations (11%), individuals and organizations not classified (6%), federal government 

agencies (5%), universities (3%), and local governments (2%).

• Of these assessments, approximately 91% (95 of 105) 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.

Overall Results

• For each of the 105 requests, NIOSH evaluated the filtration efficiency for each of the individual 

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

determined whether: 1) all units within the assessment tested above 95% efficiency; 2) all units 

tested within the assessment tested below 95% efficiency; or 3) if there were a mixture of 

units—some testing above 95% and some testing below 95%. 

o In 35 of the assessments (33%), all individual units tested above 95% particulate 

filtration efficiency. In 42 of the assessments (40%), all individual units tested below 

95%. In the remaining 28 assessments (27%), there was a mix of units that tested above 

and below 95%. See Figure 1. 
Figure 1: Overall Filtration Efficiency Results

Results by International Standard

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

percent 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 5 of the 6 assessments (83%) conducted on devices that claimed conformance with 

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

units from the single assessment (100.0%) 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 single assessment (100.0%) conducted on devices that claimed conformance 

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

95%. All units from 18 of 22 assessments (82%) that claimed to conform with both 

EN149-2001 and GB2626-2006 (international standards originating in Europe and China, 

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

Standard Assessment Results Number of 

Assessments

Approximate 

Percent of 

Assessments 

for each 

Standard

Brazil ABNT/NBR 13698:2011 All above 95% 0 0%

All below 95% 0 0%

Some above and Some below 95% 1 100%

Europe EN149-2001 All above 95% 5 42%

All below 95% 5 42%

Some above and Some below 95% 2 16%

Europe/China EN149-2001 & 

GB2626-2006 All above 95% 0 0%

All below 95% 18 82%

Some above and Some below 95% 4 18%

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% 5 83%

All below 95% 0 0%

Some above and Some below 95% 1 17%

China GB2626-2006 All above 95% 22 37%

All below 95% 17 29%

Some above and Some below 95% 20 34%

Korea KMOEL-2017-64 All above 95% 1 100%

All below 95% 0 0%

Some above and Some below 95% 0 0%

UNKNOWN All above 95% 2 67%

All below 95% 1 33%

Some above and Some below 95% 0 0%

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 42CFR84 for explanation of quality requirements NIOSH-approved 

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 this 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 discussed previously, each individual assessment tested at least 10 different units that were

submitted with the same label and packaging. There were 105 assessments conducted.

• 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.

• 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 105 assessments suggested that:

o 24 (23%) had greater than a 15% range in filtration efficiencies;

o 33 (31%) had between a 5% and 15% range in filtration efficiencies;

o 28 (27%) had between a 1% and 5% range in filtration efficiencies;

o 20 (19%) had between a 0% and 1% range in filtration efficiencies.

• Table 2 reports the greatest and least ranges observed among assessments based on the

reported international standard.

o Across the 105 assessments, the minimum range in filtration results was 0.09%

corresponding to a sample of 10 units that claimed to conform with KMOEL-2017-64:

the maximum filtration observed being 99.94% and the minimum being 99.85%.

o Across the 105 assessments, the greatest range in filtration results was 77.50%

corresponding to a sample of 10 units that claimed to conform with GB2626-2006: the

maximum filtration observed being 91.10% and the minimum being 13.60%. 

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

International Standard Claimed

Standard Lowest Range in Filtration 

Performance (%)

Highest Range in Filtration 

Performance (%)

Number of Assessments

Brazil ABNT/NBR 13698:2011 6.34 6.34 1

Europe EN149-2001 0.40 26.86 12

Europe/China EN149-2001 & 

GB2626-2006 2.05 39.89 22

China GB/T 32610-2016 9.10 9.10 1

China GB19083-2010 0.71 4.97 6

China GB2626-2006 0.09 77.50 59

Korea KMOEL-2017-64 0.09 0.09 1

UNKNOWN 0.16 55.90 3

Overall 0.09 77.50 105

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. 
CASE Conclusion 

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

most of the models assessed. Further, in 40% of the assessments, all units tested below 95%. 

Based in-part on these results, on May 7, 2020, the FDA removed 57 respirators from their 

International EUA list (FDA 2020). The FDA also instituted new sampling and evaluation procedures 

designed to increase the statistical power and the ability for each assessment to uncover distinct 

pockets of filtration performance within consistently labeled respiratory protection devices. 

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 NIOSH international assessment results webpage only provide 

an indication of filtration efficiency and confirm neither that the product performs equivalent with a 

NIOSH-approved N95 nor that it conforms with the standard requirements claimed by the 

manufacturer.

What the User/Purchaser Can Do when Purchasing Non-NIOSHApproved International Respiratory Protective Devices 

• Healthcare organizations should review the FDA EUAs prior to purchasing any Non-NIOSHapproved respirator.

• Review the NIOSH Respirator Assessment Results webpage prior to purchasing respirators that 

claim to meet the standards identified in Table 1.

• Refer to the following guidance to evaluate respirators from other countries to determine if 

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.
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: first phase by 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 P2020-0112.