Kn95 respirator is based on the Chinese standard GB 2626-2006 respiratory protective equipment self suction filter type particle respirator. According to the filtration performance, the filter elements are divided into kn and KP. Kn is suitable for filtering non oil particles, and KP is suitable for filtering oil and non oil particles. According to the level of filtering efficiency and the level of filtering elements, masks can be divided into six categories: Kn90, kn95, kn100, kp90, kp95 and kp100 (among them, full masks do not include Kn90 and kp90). Kn95 respirator is a self-priming filter type anti particle respirator with filtration efficiency of over 95% for non oil particles.
N95 respirator is in accordance with appendix K of niosh-42cfr part 84 standard certification for respiratory protective equipment filter. Appendix K divides the filter into self-priming filter type anti particle respirator and air supply filter type anti particle respirator. According to the filtration performance, the filter elements of self-priming filter are divided into three categories: n, R and P. category n is suitable for filtration of non oil particles, while category R and P are suitable for filtration of oil and non oil particles. The service time limit of class P filter element is longer than that of class R filter element. The service time of class R filter element is generally 1 working day. Class P filter element can be recommended by the manufacturer according to the demand. According to the filter efficiency level and filter element level, masks can be divided into N95, n99, N100; R95, R99, R100; p95, p99, P100. N95 respirator is a self-priming filter type anti particle respirator with filtration efficiency of over 95% for non oil particles.
Therefore, Conceptually speaking, kn95 and N95 respirators are self-priming filter respirators with filtration efficiency of over 95% for non oil particles.
Key assessment index difference between kn95 and N95
There are many similarities between kn95 and N95 in terms of assessment indexes, such as filtration efficiency, respiratory resistance, air tightness of exhalation valve, vision, headband, component requirements, information provided by the manufacturer, packaging, etc. Kn95’s assessment indexes include leakage, dead cavity, air tightness, flammability, cleaning and disinfection, etc. Note: from July 1 this year, the new standard GB 2626-2019 will be implemented. The assessment index adds the assessment of practical performance. The subjective assessment provided by the subjects can more comprehensively reflect the performance of the mask in use.
The respiratory resistance requirements of kn95 respirator in GB 2626-2006 are consistent with that of N95. However, it should be noted that GB 2626-2019 has adjusted the requirements of respiratory resistance, and specific regulations have been made for the presence or absence of respiratory valve, and the overall requirements are higher than N95. For example, the exhalation resistance of N95 with American Standard breathing valve is required to be lower than 250pa, while kn95 is required to be lower than 150pa, with a decrease of 40%. Therefore, kn95, which meets the new standard, is superior to N95 in terms of comfort.
For kn95 respirator, its headband needs to be tested in tension, while for N95 respirator, there is no specific requirement for the tension value that headband needs to meet.
Kn95 masks have specific numerical requirements for dead cavity and field of vision, but N95 does not.
In the aspect of filter efficiency test, the test conditions are the same, but in the aspect of sample pretreatment, kn95 program is more complex and more demanding than N95 program, which puts forward higher requirements for filter efficiency of respirator. The 2019 version of the new standard also adds cleaning and / or disinfection pretreatment to products that claim to be cleanable and / or sterile.
Kn95 and N95 are basically the same in the test of respiratory resistance and air tightness of expiratory valve, but kn95 needs to test the pretreated sample as well as the untreated sample. The evaluation of these two indexes is more comprehensive and accurate.
By comparing the detection standards of kn95 and N95 respirators, it can be found that kn95 respirators and N95 respirators have the same requirements in particle filtration efficiency, respiratory resistance, air tightness of exhalation valve and other key indicators. However, kn95 respirator needs more complex and harsh pre-treatment conditions in the test process, and there are specific numerical requirements for headband tension, connecting and connecting parts, dead cavity, field of vision and other indicators, while N95 does not.
Therefore, on the whole, kn95 masks have more requirements than N95 masks and higher comprehensive requirements! On July 1 this year, the implementation of GB 2626-2019 will put forward higher requirements for kn95 masks in terms of respiratory resistance, air tightness, practical performance, cleaning and disinfection, which can better reflect the performance of masks in actual use.