Yes, an N95 is a respirator. Its full technical name is a “filtering facepiece respirator,” and it is certified by the National Institute for Occupational Safety and Health (NIOSH), a division of the CDC. The “N95” designation is actually a registered certification trademark of the U.S. Department of Health and Human Services, meaning only respirators that pass NIOSH testing can carry the label.
What Makes It a Respirator, Not a Mask
The distinction between a respirator and a mask comes down to seal and filtration. A surgical mask is a loose-fitting device that creates a physical barrier but does not seal around your nose and mouth. Air slips in around the edges. An N95 respirator, by contrast, is designed to achieve a very close facial fit using elastic headbands and an adjustable metal nosepiece, forming a seal so that the air you breathe passes through the filter material rather than around it.
This seal is the reason N95s require fit testing in workplace settings. OSHA mandates that workers pass a fit test before using any tight-fitting respirator on the job, and that test must be repeated annually and for each respirator model worn. Fit testing comes in two forms: a qualitative version where you try to detect a taste or smell through the respirator (pass/fail), and a quantitative version that uses instruments to measure exactly how much air leaks past the seal.
What “N95” Actually Means
The name breaks down into two parts. The “N” means the filter is not resistant to oil-based particles, which matters in certain industrial environments but is irrelevant for biological hazards like viruses and bacteria. The “95” means the filter captures at least 95% of airborne particles.
What surprises most people is the particle size used in testing. NIOSH tests N95 filters against a sodium chloride aerosol with particles averaging just 0.075 micrometers in diameter, far smaller than the 0.3-micron figure often cited. The filters work through two mechanisms: mechanical filtration, where fibers physically block particles, and electrostatic attraction, where a static charge on the filter fibers pulls particles in and traps them. This combination is why N95s can capture particles much smaller than the gaps between individual fibers.
Industrial N95 vs. Surgical N95
Most N95 respirators are manufactured for construction and industrial jobs where workers encounter dust, mist, and fumes. These are regulated solely by NIOSH. A surgical N95 is a separate product that meets the same filtration standard but adds a fluid-resistant outer layer to protect against splashes and sprays. Surgical N95s carry dual regulation: NIOSH certifies the filtration, and the FDA regulates them as Class II medical devices. Both types filter identically. The surgical version simply adds a layer of protection relevant to healthcare settings where blood or other body fluids are a concern.
How N95s Compare to KN95 and KF94
Several international standards produce respirators with similar performance. KN95 respirators are the Chinese equivalent, rated to filter 95% of particles. KF94 respirators follow South Korean standards and filter 94% of particles down to 0.3 microns. The core filtration numbers are comparable, but the regulatory oversight differs significantly.
N95s undergo NIOSH inspection and certification in the United States, which includes ongoing quality checks. KN95s are regulated by the Chinese government, making it harder to verify quality when purchasing them outside China. The physical designs also differ. N95s typically use elastic headbands for a tighter seal, while KN95s and KF94s often use ear loops. KN95s tend to have a tent-like shape that creates a small pocket of air between the fabric and your face, which many people find more comfortable and less stifling, though ear loops generally produce a less secure seal than headbands.
Why the Distinction Matters
Calling an N95 a “mask” understates what it does. Cloth face coverings and surgical masks reduce the spread of respiratory droplets, mostly protecting the people around you. An N95 respirator protects the person wearing it by filtering the air coming in. When properly fitted, it blocks at least 95% of airborne particles, including fine aerosols that can carry viruses and bacteria.
If you are buying an N95 for personal protection, look for “NIOSH” and the N95 rating printed directly on the respirator. Counterfeit and mislabeled products exist, and the NIOSH marking is your confirmation that the device has been tested and certified to meet federal filtration standards. A genuine NIOSH-approved N95 is, by definition, a respirator.