You’ve heard of N95 and KN95 masks – but have you heard of the KF94, and what’s the difference between the three?
There are very high quality masks on the market with different letters and numbers. Understandably, this can be confusing. However, to decipher their differences and how each one works, you need to understand what the different letters and numbers represent.
“The number on all of these refers to the filtering efficiency, hence the percentage of articles that stop it from coming through,” said Dr. John Volckens, a professor of mechanical engineering at Colorado State University, said.
A KN95 filters 95 percent of particles, and an N95 as well. A KF94 filters 94 percent of particles. The difference between the letters is the certification of the government.
“The N in N95 stands for NIOSH [The National Institute for Occupational Safety and Health]”And that’s the American standard, and that’s a professional standard,” Volckens said. KN95 is a Chinese standard that is close to the American standard and KF94 is a Korean standard. “
“N” is also a NIOSH rating for non-oil resistant masks.
KF literally stands for ‘Korean filter’. A study published in 2020 showed that KF94 masks are comparable to the N95 to block SARS-CoV-2 particles, and more effective than a surgical mask. However, the study was fairly limited, as only seven patients with SARS-CoV-2 infection participated.
“It seems that KF94s are cheaper available than the N95, cheaper [generally under $2 each] and easier to use for many people, ‘said Sonali Advani, an assistant professor of medicine at Duke University. NPR. “KF94 is actually intended for public use. In Korea, they are regularly worn by ordinary citizens to filter out dust or pollution.”
Volckens explained that N95 masks have only been certified by one laboratory that is part of the Centers for Disease Control & Prevention (CDC), and that is partly why the demand cannot currently be met.
“They are very strict about who makes them an N95, and therefore you do not see much of it on the market anymore, because they were all bought,” Volckens said. “The problem with KN95 and KN94s is that there are a lot of fraudsters on the market, and we do not know what you are buying.”
When it comes to N95 masks, each mask has a stamp that says it is NIOSH certified with a certification number that you can look up online. Volckens added there are also masks with ASTM [American Society for Testing and Materials] standards that are “almost equivalent” to N95 masks – such as the FFP2, which stands for the “filter of face piece two-level” mask.
In some parts of Europe, such as Germany, federal and state governments recommend that FFP2 masks be used in shops and on public transportation. According to NPR, Austria makes similar recommendations. In France, the High Council for Public Health has announced that it is also recommending that people wear surgical masks in public – instead of dust masks.
In the US, the CDC recommends recommending dust masks to the general public, as long as it has at least two layers.
Volckens said when buying a dust mask, you need to look at three key features: fit, filtration and respiration.
“Filtration ability of the fabric, you want an extremely effective filter, you want a fit – and that’s a personal thing, but you want the mask to fit all over your face, and then breathing, you need to be able to to breathe normally through the mask, “Volckens said.” If it’s uncomfortable to breathe through, you are not going to wear it, and it can be unsafe. “
Of course, it is difficult to know the fit of a mask until it is purchased. Volckens said people should buy masks from a supplier that has been filter tested. As for the mask fit, it can be reconciled with double masking.
“Therefore, you can double a mask because you can buy a mask that does not fit well, but then use something else to keep that mask closer to your face,” Volckens said. “This is what we’re talking about, that double masking is effective for fit.”