The problem, though, is that buying masks online is almost (almost) as fraught as online dating. With counterfeit products, misleading marketing, and a real lack of any government oversight, it’s a retail quagmire. I should know, I purchased what I thought were KF94 masks online two weeks ago. What showed up was not that.
To keep yourself from making my $64 mistake, learn the basics on how masks are classified, how online retailers work, and what to look for before you hit “add to cart.”
Decoding N95, KN95, and KF94
Masks are rated by how well they’re supposed to filter out particles. For example, N95s should filter out 95 percent of all particles around .3 microns in size, says Eugenia O’Kelly, a Ph.D. candidate and principal investigator of the Respirator Protection Engineering Task Force at Cambridge University. KF94s, therefore, promise to filter out 94 percent of particles around .3 microns. And, in theory, then, KN95s should filter out 95 percent of particles too, but, quality control has been a real problem (more on that below).
Should we all have N95 masks?
The short answer is yes. Unfortunately, a year into this pandemic, N95s—especially those made by 3M—are still hard to get. Those are the gold-standard in the U.S., says Aaron Collins. A mechanical engineer by day, Collins’ master’s degree research focused on aerosols. He’s been testing masks in this bathroom and posting YouTube videos about their efficacy since this summer. Because there’s so little info available about many of the masks Americans have been purchasing (or making) during the pandemic, Collins’ videos have garnered a loyal following.
In school, Collins remembers learning about the SARS and MERS outbreaks of the early 2000s. “At the time, we learned, if this happens again, we need to have really good masks; you know, an N95 for everyone,” he says. “And as a student, you’re like, yeah right, that would never happen, modern technology will prevent [an out-of-control pandemic] from happening,” he adds.
It happened. And it’s clear we won’t have N95s for everyone anytime soon—so it’s time to look at other options.
How do KN95 and KF94 masks compare?
When N95s vanished from store shelves last March, many Americans ordered KN95s. KN95 is a Chinese particulate standard. The problem, however, has been quality control. Collins tested several KN95s that registered in the low 80s for filtration efficiency—far less than the 95 percent efficiency advertised.
The South Korean standard KF94 masks, on the other hand, performed better in testing than Collins expected—typically greater than 98 percent filtration efficiency. Because South Korea had a number of SARS cases back in the early 2000s, the South Korean government “came up with a standard of like, how would you put masks on the general population in the case of a pandemic,” Collins explains. The KF94, a mask that was cheap to produce but could reliably filter out 94 percent of particles, was born.
The difference between the KN95 and the KF94 is that the South Korean government’s Ministry of Food and Drug Safety rigorously tests and oversees the manufacture and distribution of KF94 masks. “The KF94 [certification] standard is really close to our N95 standard,” he says. While the 3M N95 is the gold standard for health care workers in the US several KF94 masks Collins tested performed better than N95 masks from brands other than 3M. (Click here for a spreadsheet of his results.)
We are only now getting our hands on KF94s because the South Korean government has closely tracked its supplies of the masks, ensuring it doesn’t run out, says Collins. With production ramped up in South Korea, the government is finally allowing exports.
How to shop for KF94s
As KF94s become popular in the US, there’s a strong likelihood counterfeit copies will crop up. “It costs less than forty-five cents to make [a counterfeit], maybe as low as twenty cents. And you can sell them for $2.50 in the US. If you’re a fake mask manufacturer, you’re just going to make money off this,” Collins says.
A few visual cues can help. Collins says every KF94 he’s tested has had KF94 printed on the packaging. It should also have the red, white, and blue seal of the Korean government or the text 식약처 허가, which means Ministry of Food and Drug Safety approved. If the packaging is in English, similarly, look for the words “certified by the Ministry of Food and Drug Safety, South Korea.
The South Korean government keeps a database of all approved KF94 manufacturers. That would make it easy for US customers to look up whether the brand they’re about to buy is legit. Unfortunately, the site is in Korean and doesn’t mesh with Google Translate… Popular Mechanics