Masks are classified into KN and KP according to the ef […]
Masks are classified into KN and KP according to the efficiency level of the filter element. KN is suitable for preventing non-oily particulate matter, such as various types of dust, smoke and microorganisms. KP is suitable for preventing non-oily and oily particulate matter. Typical oily particulate matter such as oil fume, oil mist, asphalt smoke, particulate matter contained in diesel exhaust and coke oven smoke, etc.
Is divided into 3 levels according to its filtering effect: 95%, 99%, 99.97% (ie, referred to as 95, 99, 100). Common oil-proof particulate masks are divided into three grades: KP100, KP95 and KP90. Dust masks are divided into three levels: KN100, KN95, and KN90. In the case of KN95 masks with sodium chloride particulate matter detection, the filtration efficiency should be greater than or equal to 95%.
N95 mask is one of 9 kinds of particulate protective masks certified by NIOSH (National Institute of Occupational Safety and Health). "N" means not resistant to oil. "95" means that when exposed to special test particles with specified concentration and particle size distribution, the filtering efficiency of the mask material should be ≥95%.
In fact, the quality of the filtering effect of the mask is mainly determined by the filter material in the mask. The filter material commonly used in masks is melt-blown cloth, and the main raw material is ultrafine fibers formed from polypropylene. This material is characterized by good air filtration, low resistance, high efficiency and high dust holding capacity.
Generally speaking, the higher the protective performance of the mask, the greater the impact on the comfort performance. When people wear masks to inhale, the masks have a certain resistance to the flow of air. When the inhalation resistance is too large, some people will feel dizzy, chest tightness and other uncomfortable conditions. Therefore, the basic principles of wearing masks are scientific and reasonable wearing, standard use, and effective protection.
Choose the right mask variety
Medical protective masks should be the first choice for medical workers, and ordinary degreased gauze masks should be the first choice for ordinary citizens in daily life. On special occasions, such as visiting a doctor and visiting a patient, it is best for ordinary citizens to choose medical masks.
Choose a qualified mask
When choosing a mask, it depends on whether there is a trade name on the package, whether there is information about the manufacturer or supplier, whether there is a mask certificate or instructions for use. Disposable masks must also have a one-time mark, and the method of sterilization must be marked for reusable medical protective masks. In general, ordinary gauze masks must indicate whether they are ordinary or disinfected. The materials used in the masks should be free of odors and harmless to the human body, especially the parts of the human face that are in contact with the face should be non-irritating and allergenic.
Choose a mask and do n’t forget to check the appearance
This is a problem that we tend to ignore when we choose a mask. First of all, we must check whether the packaging of the mask is complete and whether it is damaged. There should be no holes or stains on the surface of the mask. Medical protective masks should not have an exhalation valve. For close-fitting arch masks, the horizontal diameter is not less than 14cm and the longitudinal diameter is not less than 14cm; the medical protective rectangular mask is not less than 17cm in length and the width is not less than 17cm; the ordinary degreased gauze mask is not less than 17cm in length and 13cm in width The number should not be less than 12 floors. Another thing to remind everyone is that if you choose a medical mask, you must remember to have a nose clip, which is made of bendable plastic material and has a length of not less than 8.5cm.
According to the characteristics of the new coronavirus, the masks used by medical staff can be directly put into the special medical waste yellow garbage bags. The masks used by ordinary people can be sterilized with alcohol spray, then individually sealed in plastic bags or other objects, and then discarded in closed trash cans. It should be noted that you must not touch the masks used by others to avoid cross-infection, and do not discard the used masks in your bags or pockets at will, as this is easily contaminated.