NIOSH approved means a respirator has been independently tested and certified by the National Institute for Occupational Safety and Health, a federal agency within the CDC. It is the only U.S. government certification that guarantees a respirator meets minimum filtration and breathing-resistance standards. The approval applies to the physical device itself, not to a brand or company, and every certified respirator carries a unique approval number you can verify online.
What the Approval Covers
Under federal regulation 42 CFR Part 84, NIOSH defines approval as a formal certificate stating that a specific respirator model has met every minimum requirement in the regulation. The manufacturer receives authorization to attach an approval label to that respirator, its packaging, and its instruction card, but only for units built to the exact same design and specifications that were originally tested.
NIOSH doesn’t just approve N95 masks. The Certified Equipment List includes several classes of respiratory protection: powered air-purifying respirators (PAPRs), self-contained breathing apparatus (SCBAs) used by firefighters, chemical cartridge respirators for industrial settings, and various filtering facepiece respirators. Each class has its own approval code. N95s and similar filtering facepieces fall under the 84A code, while other device types carry codes like 13F, 14G, or 23C.
How the Nine Filter Classes Work
NIOSH sorts filtering respirators into nine classes based on two variables: how well the filter captures particles and whether it resists oil-based aerosols. Three efficiency levels (95%, 99%, and 99.97%) are paired with three oil-resistance categories:
- N series (Not oil resistant): N95, N99, N100. Suitable for environments without oil-based particles.
- R series (Resistant to oil): R95, R99, R100. Offers some protection against oil aerosols but has a limited service life in those conditions.
- P series (oil Proof): P95, P99, P100. Designed for prolonged use around oil-based particles.
The number refers to the minimum percentage of airborne particles the filter must capture during testing. A “100” rating actually means 99.97% filtration, not a perfect 100%. An N95, the most commonly discussed type, filters at least 95% of non-oil airborne particles, including both large droplets and very small aerosols.
What Happens During Testing
NIOSH tests respirators under deliberately harsh conditions to ensure real-world reliability. For N-series filters, the lab aerosolizes a sodium chloride solution and pushes those particles through the filter at a flow rate of 85 liters per minute, simulating heavy breathing during physical labor. The test particles are tiny, with a median diameter of about 0.075 micrometers, and they’re electrically neutralized so they won’t cling to the filter through static charge alone. This “worst-case scenario” approach means that if a respirator passes, its filter media will perform at least as well under normal conditions.
Filtration is only part of the evaluation. NIOSH also measures breathing resistance (how hard you have to work to pull air through the filter), examines the respirator’s construction, and reviews the manufacturer’s labeling and user instructions for accuracy.
The Approval Process for Manufacturers
Getting NIOSH approval is not quick or simple. A manufacturer must first request a Potential Applicant Questionnaire from NIOSH. If those responses are satisfactory, NIOSH assigns a three-letter manufacturer code. From there, the company submits a formal application with detailed documentation, test samples, and fees.
NIOSH then tests the product in its own laboratories against the standards for that respirator class. Separately, the agency evaluates the manufacturer’s quality management system to confirm it can consistently produce respirators that match the tested design. This includes an on-site visit (called a site qualification) to every facility involved in manufacturing. Inspectors verify that quality documents, defect classification systems, and sampling plans are all in place and functioning correctly. Only after both the lab testing and the quality review pass does NIOSH issue the approval certificate.
The oversight doesn’t end there. NIOSH conducts post-market evaluations, periodically testing products already on store shelves and performing ongoing audits of approved manufacturers to confirm they’re still meeting the original qualification standards.
NIOSH Approved vs. FDA Cleared
This distinction matters, especially for N95s. A standard NIOSH-approved N95 respirator is designed to protect the wearer from inhaling hazardous particles. It fits tightly to the face, requires formal fit testing, and filters at least 95% of airborne particles when properly sealed.
A surgical N95 carries both NIOSH approval and FDA clearance. The NIOSH approval certifies its filtration performance. The FDA clearance adds a requirement for fluid resistance, meaning the mask can block splashes of blood or other bodily fluids. Surgical N95s protect both the wearer (from inhaling particles) and the patient (from the wearer’s respiratory emissions).
A standard surgical mask, by contrast, is only FDA cleared. It is loose-fitting, does not require fit testing, and does not provide a reliable seal against small airborne particles. It is not considered respiratory protection under NIOSH standards. If you see a product labeled as a surgical mask with a NIOSH approval claim, that’s a red flag.
How to Verify a NIOSH Approval
Every NIOSH-approved respirator has a testing and certification (TC) approval number printed on the device or its packaging, formatted like TC 84A-XXXX. You can look this number up on the NIOSH Certified Equipment List (CEL), a free searchable database on the CDC website. Enter the approval code followed by a dash and four digits. If the search returns no results, the number is not valid, and the product is not NIOSH approved.
Beyond the approval number, genuine NIOSH-approved respirators display the NIOSH name or logo and the filter class (such as N95 or P100) on the respirator itself. The approval label also appears on or inside the packaging.
Spotting Counterfeit Respirators
Counterfeit respirators became a significant problem during periods of high demand. NIOSH recommends watching for several warning signs when buying from third-party marketplaces or unfamiliar websites. Listings that emphasize being “legitimate” and “genuine” are often neither. Prices that seem too good to be true, sellers advertising “unlimited stock” during shortages, and sellers who primarily sell trending items rather than consistent product lines are all red flags.
On the product itself, look for bad grammar, typos, or signs of altered images on packaging. Counterfeit sellers sometimes operate cookie-cutter websites where they mix up brand names and logos, leave pages partially undone with placeholder text, or use misspelled domain names designed to look like legitimate retailers. Free email accounts as the primary business contact and broken website links are additional warning signs.
The most reliable check remains the Certified Equipment List. If the TC number on the respirator doesn’t match a valid entry in the database, the product should not be trusted regardless of how convincing the packaging looks.