The origin of KN95 and N95
KN95 masks are based on the Chinese standard GB 2626-2006 "Self-priming filter type anti-particulate respirator for respiratory protective equipment". The filter elements are divided into KN and KP according to the filtering performance. KN is suitable for filtering non-oily particles, and KP is suitable for filtering oily and Non-oily particles. According to the level of filtration efficiency and the level of filter elements, masks can be divided into six categories: KN90, KN95, KN100, KP90, KP95, and KP100 (the full face mask does not contain KN90 and KP90). KN95 mask is a self-priming filter anti-particle respirator with a filtration efficiency of more than 95% for non-oily particles.
The N95 mask is based on the United States Code of Federal Regulations NIOSH-42CFR Part84 "Respiratory Protective Equipment Standard Certification" Appendix K-filter type anti-particle filter. Appendix K divides the filter into self-priming filter type anti-particulate respirator and air supply filter type anti-particulate respirator. Self-priming filter anti-particle filter filter elements are divided into three categories according to filtering performance: N, R, and P. N category is suitable for filtering non-oily particles, and R and P categories are suitable for filtering oily and non-oily particles. The use time limit of P type filter element is longer than that of R type. The use time of R type filter element is generally 1 working day. P type can be recommended by the manufacturer according to the demand. According to the level of filtration efficiency and the level of filter elements, masks can be divided into N95, N99, N100; R95, R99, R100; P95, P99, P100. N95 mask is a self-priming filter anti-particle respirator with a filtration efficiency of more than 95% for non-oily particles.#p##e#
Therefore, conceptually, both KN95 and N95 masks are self-priming filter anti-particle respirators with a filtration efficiency of more than 95% for non-oily particles. Since the concept is the same, are the assessment indicators of the two masks the same?
KN95 and N95 key assessment indicators difference
At present, the testing basis for KN95 masks in my country is GB 2626-2006, which is somewhat different from the N95 assessment indicators.
It can be seen from Table 1: KN95 and N95 have many similarities in the assessment indicators, such as filtration efficiency, breathing resistance, air tightness of the exhalation valve, field of view, headband, component requirements, information provided by the manufacturer, packaging, etc. . The assessment indicators of KN95 increase leakage, dead space, air tightness, flammability, cleaning and disinfection, etc. Note: From July 1st this year, the new standard GB 2626-2019 will be implemented. The assessment indicators have increased the assessment of practical performance. Subjective evaluation provided by the subjects can more fully reflect the performance of the mask during use.
Analysis of key technical indicators requirements
It can be seen from Table 2 that there is a certain difference between the requirements of KN95 and N95 mask indicators. On the whole, KN95 has higher requirements.
①The breathing resistance requirements of KN95 masks in GB 2626-2006 are consistent with those of N95. But it should be noted: GB 2626-2019 has adjusted the requirements of breathing resistance, and made specific regulations for whether there is a breathing valve, and the overall requirement is higher than N95. For example, the N95 exhalation resistance with breathing valve in the American standard requires less than 250Pa, while the KN95 requires less than 150Pa, a 40% decrease. Therefore, KN95, which meets the new standard, is superior to N95 in terms of comfort.#p##e#
②KN95 masks require a tensile test on the headband, while N95 masks have no specific requirements for the tensile strength of the headband.
③KN95 mask has specific numerical requirements for dead space and visual field, while N95 does not.
KN95 and N95 key assessment index test method difference
1. Filtration efficiency:
It can be seen from Table 3 and Table 4 that in terms of filtration efficiency test, the test conditions are the same, but in terms of sample pretreatment, KN95 has more complicated procedures and more demanding conditions than N95, and it proposes a higher filtration efficiency for masks. Requirements. The 2019 version of the new standard also adds cleaning and/or disinfection pretreatment to products that claim to be washable and/or disinfected.
2. Breathing resistance and air tightness of exhalation valve:
It can be seen from Table 5 that KN95 and N95 are basically the same in the testing of the two indexes of breathing resistance and exhalation valve air tightness test, but KN95 tests samples after pretreatment in addition to unprocessed samples. The evaluation of these two indicators of masks is more comprehensive and accurate.
By comparing the corresponding test standards of KN95 and N95 masks, it can be found that KN95 masks and N95 masks have the same requirements on key indicators such as particle filtration efficiency, breathing resistance, and air tightness of the exhalation valve. However, the pretreatment conditions that the KN95 mask needs to go through in the test process are more complicated and harsh, and there are specific numerical requirements for indicators such as headband tension, connection and connection parts, dead space, and visual field, while N95 does not.
Therefore, on the whole, KN95 masks require more requirements than N95 masks, and the overall requirements are higher! On July 1 this year, GB 2626-2019 will be implemented, which will improve the breathing resistance, air tightness, practical performance, and cleaning of KN95 masks. Higher requirements are put forward in terms of disinfection and disinfection, which can better reflect the performance of the mask during actual use. Therefore, whether it is a new standard or an old standard, as long as the KN 95 mask battle N95 mask meets the standard requirements, it is proper! ( Source: 12360 Customs Hotline)