Some KF94 masks. Pictured masks are the classic "boat style" KF94. Note that masklab (pictured) is not a certified KF94, but is "KF style." Left to right: masklab, masklab, BOTN large black, masklab, BOTN large black, Bluna Face Fit, LG Airwasher, masklab.
Several individuals wearing KF94 masks while meeting South Korean presidential candidate  Hong Joon-pyo on September 19, 2021. Photo CC-BY-SA 고려.

KF94 is a South Korean general-public mask standard. Most KF94 masks feature a boat-style design and attach to the face using ear loops. The "KF" stands for "Korea Filter." KF94 masks are certified to have at least a 94% particle filtration efficacy and a mean total inward leakage of less than 11% across test subjects.

KF94s are made in two form factors: the classic "boat style" (sometimes called "3D") design and a bifold (sometimes called "2D") design. All certified KF94 masks are made in South Korea.

KF94 masks are certified by the South Korean Ministry of Food and Drug Safety in a manner similar to how the US-based NIOSH certifies N95 respirators. KF94 are not exactly equivalent to US N95; a different Korean standard, "1st class" (KMOEL-2017-64) is more like the NIOSH N95 standard. K94 is a general-public mask standard, not designed for industrial or occupational use like NIOSH N95. For instance, there are KF94 masks available for children, but in the US there are no official NIOSH-certified N95s for children, as NIOSH is for occupational safety (the "O").

In addition to KF94, in Korea there are also "KF80" masks, which meet a less rigorous filtration standard.

The 3M Aura is a N95 respirator with a boat-style design akin to the popular boat-style KF94.

More on KF94 masks

KF94 style masks worn by WNBA championship winning team-members at the White House. Official White House photo by Adam Schultz, US government work in public domain, August 23, 2021.
In addition to the iconic boat style (sometimes called "3D") KF94 design, there is also a bifold ("2D") KF94 design.

Technical details of K94 standard

The technical details of the KF94 standard can be found on the South Korean Ministry of Food and Drug Safety website (in Korean). An English-language summary document prepared by the South Korean MFDS is available.

K94 masks have a particle filtration efficiency of at least 94% using a sodium chloride and paraffin oil aerosol and a mean total inward leakage of less than 11% across a panel of test subjects. While the standard only calls for a PFE of 94%, independent tests of many KF94 masks show they almost always have a higher PFE, often in the 98+% range.

See also