뉴엠코리아

The KF(Korea Filter) rating system, certified by the Ministry of Food and Drug Safety,
is a product that has been tested by the Ministry and is divided into four KF grades (80, 94, 99, AD).

There is a slight difference from the grade approved by the Occupational Safety and Health Agency, and it is more stringent than the US National Institute of Occupational Safety and Health(NIOSH).

Korea Food and Drug Administration mask rating standard table

	standard			application example
	dust collection efficiency	inhalation resistance of the face	leakage rate
KF80 grade	80% or more (sodium chloride test)	6.2mmH20 or less	25% or less	for preventing yellow dust
KF94 grade	94% or more (sodium chloride and paraffin oil test)	7.2mmH20 or less	11% or less	for prevention of epidemics
KF99 grade	99% or more (sodium chloride and paraffin oil test)	10.3mmH20 or less	5% or less	-

* Dust collection efficiency: The rate at which the mask filters dust when the wearer inhales
* Inhalation resistance of the face: Resistance inside the mask when the wearer inhales
* Leakage rate: the rate of air leakage through the gap between the mask and the face

1. Measurement of dust collection efficiency

Measurement of dust collection efficiency is carried out in two types of tests: “sodium chloride” and “paraffin oil”(six times each)
-With 6 products(3 are intact, and the remaining 3 are used after being left in a designated environment for about 24 hours.)
-Maintain the specified level of sodium chloride aerosol (or paraffin oil) concentration in the test space.
-Put the facial part of the sample into the automatic filter inspection equipment and pass sodium chloride aerosol (or paraffin oil) through the face at a flow rate of 95L per minute.
-The concentration before and after passing through the face is measured, and the measured value is the average value obtained within about 30 seconds.

2. Leak rate measurement

Leakage rate measurement is a result of 30 tests(3 times x 10 females or males).
-Five out of ten products are used as they are, and the remaining five are used after being left in a designated environment for about 24 hours.
-Maintain the specified concentration of sodium chloride aerosol in the test space.

When the above environment is created, measure with the following exercise.
-Walk for 2 minutes without moving your head or talking (treadmill at 6km per hour)
-Move your head from side to side 15 times for about 2 minutes, as if examining the wall of the tunnel.
-Move your head up and down 15 times for about 2 minutes, as if examining the roof and floor.
-Speak Korean sentences aloud for 2 minutes.
-After each exercise, the average concentration of sodium chloride aerosol inside the mask is substituted into the formula below to measure the leak rate: at least 80% of the measured must meet the reference value.

Mask performance for passing test standards
-KF80: 80% or more of the dust is blocked when the particle size is about 0.6μm / Suitable for preventing fine dust and dust
-KF94: When dust particle size is about 0.4μm, 94% or more of the dust is blocked / Suitable for preventing fine dust and dust + epidemics
-KF99: 99% or more of the dust is blocked when the particle size is about 0.4μm / Suitable for prevention of fine dust and yellow dust + prevention of dust