How to distinguish the category of masks

- Mar 25, 2020-

According to the standard classification, the N marked on the mask represents the American standard, FFP is the European standard, and KN is the Chinese standard.

FFP European standard masks are certified by the European Standards Council respiratory protective gear. The standard is to divide the granular protective filter material into two types: solid particle protection and liquid particle protection. They are tested and classified with NaCL (sodium chloride) and DOP (paraffin oil) aerosols. The function is to adsorb harmful aerosols, including dust, fume, mist droplets, poisonous gases and poisonous vapors, through the filter material, blocking them from being inhaled by humans. Qualified solid particle protection filter materials are divided into three levels of P1 (FFP1), P2 (FFP2), and P3 (FFP3) according to the tested particle transmission rate. The minimum filtering effect of FFP1 is 80%, and the minimum filtering effect of FFP2 is 94%. , FFP3 minimum filtering effect ≥97%.

The American standard masks are graded by the National Institute of Occupational Safety and Health (NIOSH) for the filter material and filtration efficiency of the masks. This standard has the highest recognition in the world.

There are three types of filter materials according to the middle layer of the mask:

N is Not resistant to oil, which can protect non-oily suspended particles. For example, the oil fume produced by cooking is oily particulate matter, and the droplets produced by people speaking or coughing are not oily. Generally, non-oily particles refer to coal dust, cement dust, acid mist, microorganisms, and the like. In the haze pollution currently raging, suspended particles are mostly non-oily. The oily particles refer to oil fume, oil mist and asphalt fume.

R is Resistant to oil, which can protect non-oily and oily suspended particles, but when used for oily particles, the use time should not exceed 8 hours.

 P is the oil proof, which can protect non-oily and oily suspended particles. Compared with the R series, the P series is used for a relatively long time, according to the labels of different manufacturers.

KN is a Chinese standard, and its detection method is the same as that of the United States. According to China ’s GB2626-2006 standard, masks are classified into KN and KP categories. KN means that the mask is suitable for filtering non-oily particles, and KP means that the mask is suitable for filtering oil And non-oily particles. The number after the letter represents the protection level of the mask. The larger the number, the higher the protection level.

How should the protection level be converted between three different standard masks? Obviously, the FFP of the European Union can filter non-oily and oily particles at the same time, while the US and China's N and KN can only effectively filter non-oily particles. Therefore, their protective effect formula is roughly: FFP3> FFP2 = N95 = KN95> KN90.