Are you using NIOSH approved N95 respirators? - Worksite Medical
Get Your Quote!

The National Institute for Occupational Safety and Health (NIOSH) has issued two new fact sheets on filtering facepiece respirators.

One gives criteria for assessing if an N95 filter is approved by the agency and the other provides procedures for fit testing and testing filtration efficiency. 

Respirators approved by NIOSH are proven to be effective and will work as expected, as long as they are properly maintained, worn and used correctly, fitted properly, and replaced based on manufacturer recommendations. 

According to the agency, “NIOSH only approves respirators that pass its strict quality assurance and performance requirements.”

Tests utilize the worst-case scenario, using particles that are best able to make it through a filter. A proper N95 mask must block at least 95 percent of those particles in order to be considered effective. 


How to tell if you’re using NIOSH approved respirators


The simplest way to tell if your N95 mask is NIOSH approved is by searching for it on the NIOSH Certified Equipment List (CEL).

Niosh approved respirator safety refresher

Download the respirator refresher safety training guide here.

All approved respirators have a testing and certification approval number that is printed on the mask.

Respirators can be labeled “N95,” and still not be approved by NIOSH. These masks cannot be relied on to provide the same level of respiratory protection.

The slightest modifications to even approved respirators void their certification. 


FFR Fit Testing by Employers 


NIOSH certification guarantees filtration efficiency, but not protection.

If a mask does not properly fit, it does not provide optimal protection. Respirators should form a tight seal to the face, otherwise, particles can leak into the breathing area. That’s why you need to conduct respirator fit tests at least once per year, or when conditions change.

Related: Respirator Fit Testing is Required Every Year

Qualitative or quantitative fit testing may be used.

Qualitative fit pass/fail tests determine respirator function by testing to see if a user can taste a test agent. These tests are performed by having a user wear a respirator and test enclosure. Then, a test agent is sprayed inside the enclosure to see if its presence can be detected by the user. If the user detects taste, then the respirator fails. 

Qualitative fit tests rely on an instrument to numerically measure any inward leakage of a respirator. These tests help to determine proper fit by giving a “fit factor” to a respirator and its user. This is expressed as the ratio of the concentration of a substance in ambient air to the concentration inside the respirator when worn. 


Get On-Site Fit Testing for N95s & More 


Need on-site respirator fit testing for your team? It’s never been easier!

Worksite Medical brings respirator fit testing to you with our convenient, compliant mobile medical units.

We perform qualitative and quantitative fit testing for all of an employer’s facepiece respirator needs. Additionally, you can get audiometric exams, OSHA & NFPA physicals, drug & alcohol testing, and any lab work you need to keep your workplace safe and compliant.

Schedule now or get your risk-free quote today by completing the form below, or by calling us at 1-844-OCCUMED! You can also email us at



About Worksite Medical

In most cases, OSHA requires medical surveillance testing, and at no cost to employees.

Worksite Medical makes that program easier with mobile medical testing.

We conduct on-site respirator fit tests, as well as audiometric exams, pulmonary function tests and heavy metal lab work, right on your job site. We also keep accurate, easy-to-access medical records for your convenience. You’ll keep your employees at work, and stay ahead of OSHA inspections.

With Worksite Medical, a mobile medical testing unit — we can bring all the resources of a lab to you. Our certified lab technicians can perform both qualitative and quantitative respirator tests to ensure a perfect fit.

Protect your team and your workplace now with Worksite Medical. Not sure what you need? Try our medical testing wizard here.


Request a Quote or Schedule Your Testing