OSHA Changes Respirator Fit Testing Standards

According to TSI Incorporated, OSHA announced changes to its Respiratory Protection Standard. The changes affect the Ambient Aerosol Condensation Nuclei Counter (CNC) Quantitative Fit Test (QNFT) Protocols in 29CFR 1910.134, Appendix A.

These changes include modified protocols for the following respirators:

• Full-facepiece and half-mask elastomeric respirators
• Filtering facepiece respirators

The new protocols are based on three studies, published in a peer-reviewed journal, demonstrating the equivalency to the original Ambient Aerosol CNC QNFT protocol. Testing speed has been reduced to 2:20 minutes, as opposed to the 7:15 minutes before the change.

The Concern with Qualitative Fit Testing

Standard qualitative fit testing is a subjective method of fit-testing that allows for a significant margin of error. This is because it relies on the user’s senses to relay information during typical testing methods (Saccharin and Bitrex).

Though qualitative methods are still in compliance with OSHA, there are now newer and safer methods of conducting respirator fit testing.

fit tester


PortaCount and the Benefits of Quantitative Fit Testing

Quantitative fit testing is an objective method that minimizes human error. This is an assessment of the adequacy of respirator fit by numerically measuring the amount of leakage into the respirator.

This method uses a machine that measures particles, effectively removing the subjective nature of a standard qualitative fit test. Studies also show that quantitative fit testing achieves higher Simulated Workplace Protection Factors (SWPF) than qualitative methods for N95 filtering facepieces.

The PortaCount can also test a variety of half and full-face respirators from all of the major manufacturers.  The quantitative testing method is a safer approach and fit test administrators no longer have to rely on a person’s senses and self-reported feedback to determine if a mask fits.

PortaCount Fit Testing


The PortaCount has many features, including real-time fit changes that can help users select the right mask and identify the best fit more quickly. On-screen video animations help guide users while conducting the fit test.

The PortaCount software is continuously updated and maintained ensuring the most accurate results. All data is securely stored and documented. The PortaCount administrator can see exactly when a test took place, by who and when they will need to be tested again.

Overall, the PortaCount is an exceptional machine that offers nearly foolproof fit testing, eliminating the subjective nature of traditional qualitative fit-testing. It helps protect workers and maintain OSHA compliance by providing accurate, real-time fit factors.

PortaCount Fit Testing Services Available

We offer PortaCount fit testing services. Contact us today for custom pricing options.