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Respirator Pre-Submission Tests – NIOSH

Respirators intended for submission to NIOSH may require NaCl, DOP, valve leak, and inhalation/exhalation tests to verify that the respirator meets the minimum performance requirements. These tests can be performed by the manufacturer or a third-party laboratory and must follow NIOSH Standard Testing Procedures (STPs) and use appropriate instrumentation. Nelson Labs offers these pre-submission testing services.

The Sodium Chloride Aerosol Challenge (NaCl) uses a widely accepted method for evaluating particle penetration and airflow resistance properties of a variety of filtration materials. Other materials, such as breathing system filters, face masks, etc. are tested to determine filtration efficiency for marketing purposes.

The Dioctyl Phthalate (DOP) test is used to evaluate particle penetration and airflow resistance properties for a variety of filtration materials, including HEPA filters, NIOSH respirators, and filter media.

Testing is performed in compliance with 42 CFR Part 84 and NIOSH Procedure No. RC-APR-STP-0057, 0058 and 0059 is necessary prior to submission for NIOSH certification of respirators. Nelson Labs has extensive experience testing filters and other filtration devices.

Applicable Standards

  • NIOSH 95
  • 42 CFR Part 84
  • NIOSH Procedure No. TEB-APR-STP-0057-0058-0059


Download our respirator testing requirements PDF to assist you in determining which test is required for your location.

Testing Locations

Study Outline

Sodium Chloride Aerosol Challenge

The Sodium Chloride Aerosol Challenge test is able to determine filtration efficiency measurements up to 99.999%. In this procedure, the TSI® CERTITEST® Model 8130 Automated Filter Tester reservoir is filled with a 2% NaCl solution.* The sample is placed into the filter holder. Cone or molded masks and respirators are mounted to a test fixture and sealed into a cylinder filter holder to ensure that the mask is properly sealed.

Samples are subjected to aerosolized NaCl. The concentration of NaCl is measured before and after impact with the sample. The amount of NaCl that passes through the sample is used to calculate the filtration efficiency of the sample.

Respirators for NIOSH pre-submission are required to be preconditioned at 85 ± 5% RH and 38 ± 2.5°C for 25 hours prior to assessing the filtration efficiency.

There are three categories for NIOSH-certified, nonpowered, air-purifying, particulate-filter respirators: N (Not resistant to oil), R (Resistant to oil), and P (oil Proof).

*Only N-series filters are evaluated using a NaCl aerosol, which is slightly degrading to filter medium. Test articles intended to be resistant to oil (R-series) or oil proof (P-series) must be evaluated using an oil-based aerosol.

Test articles submitted for testing according to NIOSH requirements will be tested according to 42 CFR Part 84 “Approval of Respiratory Protective Devices.”

Dioctyl Phthalate (DOP) Challenge

The DOP aerosol test is a widely accepted method for evaluating particle penetration and air flow resistance properties of a variety of filtration materials (e.g., breathing system filters, NIOSH respirators and face masks). The procedure employs an aerosol of DOP using a TSI® CERTITEST® Model 8130 Automated Filter Tester.

Test articles are challenged with particles of the most penetrating particle size range, 0.3 µm.
Filtration efficiency measurements can be determined up to 99.999%. Samples can be tested at flow rates up to 90 liters per minute (LPM). The filtration requirement for HEPA filters is 99.97% at 0.3 µm using the DOP test.

Inhalation, Exhalation, and Valve Leak Tests

In addition to NaCl and DOP tests, mask manufacturers may be required to demonstrate inhalation, exhalation, and valve leak tests in conformance with 42 CFR Part 84 and NIOSH procedures.

If you have additional questions about Respirator Pre-submission Tests – NIOSH testing, or would like to consult with the experts at Nelson Labs, just send us a request or call us at +1 (801) 290-7500.