Any bona fide N95 has been certified to filter at least 95% of particles.
N95s with valves were produced for industrial settings that focused on keeping dust from getting in the mask rather than stopping pathogens from getting out, Eby said.
As such, N95 masks without a valve are seen as the best choice in a pandemic.
"We're selling a lot more without a vent for that reason," he said.
What is a KN95?
An N95 is certified by the U.S. government to be as effective as advertised. A KN95 is certified by Chinese government standards to filter 95% of particles.
The CDC warns that "about 60% of the KN95 respirators in the United States are counterfeit" and don't meet U.S. safety guidelines.
How to spot a counterfeit?
Counterfeit N95 and KN95 sales flourished while respirators were in short supply and largely diverted to health care workers in 2020.
The risks are lower when buying from mainstream retail outlets, but the CDC says to watch for a lack of markings on the respirator or headband and the use of ear loops instead of dual headbands.©2022 StarTribune. Visit at startribune.com. Distributed by Tribune Content Agency, LLC.