NIOSH Respirator Testing & Filtration Material Testing

Get certified accurate results in as little as 3 business days.

4C Air is Trusted by Leading Organizations & Educational Institutes

As a member of the World Health Organization DeMaND Team, 4C Air aids in research and mask testing. Our work has been used and cited by the CDC for national mask guidance.  Learn more about our testing services below 

Mask Testing Services Offered

4C Air is a testing lab with extensive experience performing NIOSH tests that comply with NIOSH testing standards and US 42 CFR 84 filter assessments. 

For organizations looking to obtain NIOSH pre-submission (precertification) for N95, N99, N100, P95, P99, P100, R95, R99, R100 and all classes of non-valved respirators. Our results have been successfully used for NIOSH pre-submission. 

Results can be provided as quick as 3-7 business days. 


TEB-APR-STP-0059 : N95 Filtration Efficiency Testing

This procedure establishes the means for ensuring that particulate filtration efficiency of N95 series filters used for non powered respirators.  This test is for initial submission approval, extension of approval, of for Certified Product Audits to meet the minimum requirements per 42 CFR, Part 84, Subpart K, 84.181.   

Full STP documentation can be downloaded here: PDF

TEB-APR-STP-0003 : Exhalation Resistance Testing

This procedure is used to ensure exhalation resistance meets minimum requirements per 42 CFR Subpart I, 84.122, Subpart K, 84.180, Subpart L, 84.203, Subpart KK 84.1149 and 84.156(a)(1, 2).

Full STP Documentation can downloaded here: PDF 

TEB-APR-STP-0007 : Inhalation Resistance Test

This procedure is used to ensure inhalation resistance meets minimum requirements per 42 CFR Subpart I, 84.122, Subpart K, 84.180, Subpart L, 84.203, Subpart KK 84.1149 and 84.156(a)(1, 2).

Full STP Documentation can downloaded here: PDF

NIOSH Pre-submission testing faqs

Why is NIOSH pre-submission testing needed?

Before receiving NIOSH certification, manufacturers must abide by NIOSH CA 2021-1034 which requires regular NIOSH lab testing during the initial application, for quality assurance after certification is received, and/or for contracted agreements.

What is required for testing?

We require a minimum of 3 samples per brand for testing. Samples will NOT be preconditioned at 4C Air (85 ± 5% RH and 38 ± 2.5°C for 25 hours). It is the customer’s responsibility to precondition the samples if necessary. Ea, consequatur.

NIOSH Standard Application Procedure - PDF Download

You can download a PDF of the complete Standard Application Procedure for the Approval of Air-Purifying Filtering Facepiece Respirators Under 42 CFR Part 84


Precertification Respirator Testing - NIOSH

N95 Respirator Samples for Testing NIOSH precertification

NPPTL Tests - Face Masks & Respirators

For organizations looking to verify international non-NIOSH masks and respirators, we can provide a certified results in a quick and timely manner.

ASTM F3502-21 Certification

4C Air can offer  ASTM F3502-21 certified testing reports to meet certification standards.  Learn more about ASTM F3502-21 standards and testing below.

NIOSH Air Filtration Rating - How We Test

Tests will be conducted with a TSI 8130A “Automated Filter Tester”, using NaCl as the aerosol (0.26 um mass mean diameter, 0.075 um count median diameter). For mask samples, 4C Air can perform a loading test to determine the minimum efficiency, if necessary. Mask samples will be tested using 85 L/min flow rate and samples will be preconditioned prior to testing. 

Testing for oil-based aerosols can be requested, please contact us for more information

Testing is compliant with the standard testing procedures (STPs) set by NIOSH

Resources for Face Masks and Respirators

Below is a list of helpful resources for face masks and respirators from trusted sources such as the CDC and World Health Organization.

NIOSH Certification for Respirators

What is NIOSH?

NIOSH Certification stands for National Institute for Occupational Safety and Health certification. NIOSH is a part of the US Centers for Disease Control and Prevention (CDC), within the Department of Health and Human Services. The Agency focuses on worker safety and health and in the creation of safe and healthy workplaces.

What is NIOSH certification?

NIOSH provides certification for respirators as per 42 CFR part 84 regulations. The National Personal Protective Technology Laboratory (NPPTL), a division within NIOSH, is entitled to work in the field of Personal Protective Equipment (PPE). The NPPTL tests the respirator samples to evaluate their performance to see if they meet filtration standards.

How to get NIOSH certified?

Prior to applying for NIOSH certification, respirators must undergo pre-submission testing by the applicant or third party laboratory (such as 4C Air)  to ensure the respirator meets performance characteristics that comply with the NIOSH minimum 42 CFR part 84 requirements. After pre-certification, the process is as follows:

  • Request a Manufacturer’s Questionnaire from
  • Appointing Agent
  • Obtaining three (3) letter Manufacturers Code from NIOSH
  • Submitting the Standard Application Form (SAF) along with the necessary documentation, such as, performance data, pre-submission test data, proposed labeling, quality manual and inspection procedures, PQPs, drawings, user instructions, etc., along with the test samples.
  • Payment of fees

Upon receiving the application, NIOSH will go through the following evaluation stages:

  • Initial review
  • Quality assurance review
  • NPPTL testing of the respirator samples
  • Final review
  • Manufacturing site audit to evaluate if the manufacturing practices are consistent with the submitted documentation and in compliance with NIOSH requirements
  • Site Qualification and NIOSH approval

A more fully detailed list of processes can be found by clicking here.

Click here to apply for  qualified pre-certification lab testing. 

What are the NIOSH filter ratings and requirements?
  • N95 respirators filter at least 95% of airborne particles and are not resistance to oil.
  • Surgical N95 respirators filter at least 95% of airborne particles and are cleared by the FDA as a surgical mask.
  • N99 respirators filter at least 99% of airborne particles and are not resistant to oil.
  • N100 respirators filter at least 99.97% of airborne particles and are not resistant to oil.
  • R95 respirators filter at least 95% of airborne particles and are resistant to oil.
  • P95 respirators filter at least 95% of airborne particles and are strongly resistant to oil.
  • P99 respirators filter at least 99% of airborne particles and are strongly resistant to oil.
  • P100 respirators filter at least 99.97% of airborne particles and are strongly resistant to oil.

Mask and Respirator Fit Testing

Resources for Respirator Program Administrators

Selecting Respirator Devices

A CDC graphic providing a guide to selecting a respirator or mask. 

Facial Hairstyles and Filtering Facepiece Respirators

A CDC graphic detailing different facial hair uses with tight fitting respirators.

Why are N95 Fit Tests required?

CDC supplied graphic for why annual fit testing is required. 

Summary of Respiration Fit Test Requirements

CDC infographic explaining who needs to get fit tested, how to get fit tested, and the required follow up.

  • Whenever a different size, style, model or make of respirator is used.
  • When any facial changes occur that could affect fit, such as significant weight fluctuation or dental work
What are the types of Fit Testing?

There are two kinds of tests: qualitative and quantitative.

What is a Qualitative Fit Test?

A qualitative fit test (QLFT) may only be used to fit-test:

  • Negative-pressure, air-purifying respirators, as long as they’ll only be used in atmospheres where the hazard is at less than 10 times the permissible exposure limit (PEL).
  • Tight fitting facepieces used with powered and atmosphere-supplying respirators.

QLFT is pass/fail and relies on the user’s senses using one of four OSHA-accepted test agents:

  • Isoamyl acetate (banana smell); only for testing respirators with organic vapor cartridges.
  • Saccharin (sweet taste); can test respirators with a particulate filter of any class.
  • Bitrex® (bitter taste); can also test respirators with particulate filters of any class.
  • Irritant smoke (involuntary cough reflex); only for testing respirators with level 100 particulate filters.

Each QLFT method uses seven exercises performed for 1 minute each:

  • Deep breathing.
  • Normal breathing.
  • Moving head side to side.
  • Moving head up and down.
  • Bending over (or jogging in place if fit test unit doesn’t permit bending at the waist).
  • Normal breathing again.
  • Talking.

More information about qualitative fit testing can be found here.

What is Quantitative Fit Testing?

A quantitative fit test (QNFT) can be used to fit-test any tight-fitting respirator. It involves using an instrument to measure leakage around the face seal and produces a numerical result called a “fit factor.” There are three OSHA-accepted QNFT test protocols:

  • Generated aerosol uses a non-hazardous aerosol such as corn oil generated in a test chamber.
  • Condensation nuclei counter (CNC) uses ambient aerosol and doesn’t require a test chamber.
  • Controlled negative pressure (CNP) uses a test that creates a vacuum by temporarily cutting off air. (There is also a fourth method, which is an abbreviated version of this one.)

QNFTs use the same seven exercises as QLFTs, plus an additional “grimace” test where the subject smiles or frowns for 15 seconds.

A fit factor of at least 100 is required for half-mask respirators and a minimum fit factor of 500 for a full facepiece negative-pressure respirator. 

More about quantitative fit testing can be found here.