Three of Four N95s Don’t Meet Fit Capabilities

Contributed by BSM Staff

WEST BRIDGEWATER, MA -- A recent comparison study of some of the most popular commercial N95 disposable respirators shows many of them struggle to seal well against the wearer's face and therefore may not protect as well as they claim.

The study was conducted using the relatively new ASTM F3407-20 Respirator Fit Capability (RFC) Standard to evaluate respirator product designs on overall fit capabilities.

The study pointed out the dangers of wearing a disposable N95 respirator without ensuring that it fits and seals well around your face. Seventy-five percent of the N95s tested did not meet the fit capability standard. As a result, they did not provide the 95 percent filtration protection they were designed for.

Global advanced materials manufacturer Shawmut Corporation recently presented the comparison study of popular commercial N95 filtering facepiece respirators at the 2022 International Society for Respiratory Protection Conference (ISRP2022). Held once every two years, the ISRP conference serves as a global forum for the exchange of knowledge related to the science, technology, regulation, development, and practice of respiratory protection.

The purpose of Shawmut's comparison study was multi-fold, with an emphasis on assessing the ability of the ASTM F3407 Respirator Fit Capability (RFC) Standard to compare the fit capability performance of a range of several popular commercial NIOSH-approved disposable N95 filtering facepiece respirators (FFRs) of various designs – molded cup, flat-fold, trifold and duckbill.

A focus was also placed on understanding how FFR design and construction factors may impact overall fit performance, as well as assessing the relative performance of other popular FFR designs in the market at the time of the study (such as KN95s) compared to N95 FFR designs.

"The ASTM RFC Standard will enable respirator manufacturers to develop better designed models that fit the worker population. Respirators passing the RFC Standard test method are expected to have better fitting characteristics for a wider range of face sizes," said James Wyner, CEO of Shawmut. "Achieving high filtration is relatively easy; achieving a good seal in a mask that has high filtration is a challenge," Wyner added. "That's why evaluating how well a respirator fits a wide range of people, in accordance with the ASTM F3407 standard, is so valuable."

To learn more about Shawmut's N95 respirator, go to