How to choose and buy masks in the period of new coronavirus pneumonia
during this time the hottest commodity is not pork, but rather masks. Although there are dozens of disposable masks at home, but not for medical use, not to mention the N95. From the day before the start thinking about N95 masks bought from the Internet, but all is not available. Although yesterday grabbed four no-name masks with breathing valve from Taobao, but a 49.9 (normal price is around 3), there is no quality assurance, I was finally back.
I am currently in once in a while Taobao, Jingdong, Suning point of view there is no N95 masks, but about two days, all is not available. Do not know when you can buy!
The most recent outbreak of pneumonia novel coronavirus infection affected the normal life of most people, for the average person can do is go outside action, and take appropriate precautions in a number of precautionary measures, especially important one is " wear a mask, "the major said today at a mask brand, model, can be worn long, what to wear and how to buy!
Choose what brand of masks
Popular speaking, 3M, Honeywell International big-name, according to "brand list" data show that in 2019 China ranked the top three market masks are: 3M, Pitta, OhSunny, Honeywell ranked seventh. But they currently supply Wuhan and other epidemic-hit areas, may also be able to buy inventory.
Select what type of masks
N95 masks at least under the current situation can only be effective against viruses, medical grade N95 masks, in addition to isolated droplets, need to have some antibacterial effect.
N95 masks Yes NIOSH one kind of nine kinds of anti-particulate respirator (National Institute for Occupational Safety and Health Institute) certified in. "N" meaning it is not suitable for oily particles (fumes cooking produced is oily particles, while people speak or cough droplets are not oil produced); "95" means, in predetermined NIOSH standard testing conditions, the filter efficiency of 95?rN95 masks the most important feature is the ability to prevent droplet infection by the patient body fluids or blood spatter caused. Droplet size is a diameter of 1 to 5 micrometers. US Occupational Safety and Health Administration (OSHA) regulations for medical institutions, exposed to the tuberculosis bacteria medical personnel must wear at least N95 standard mask.
Compared medical surgical masks, N95 masks sealed better. N95 masks in the selection, to choose N95 respiratory masks without valves.
If the level of the N95 masks can not buy, buy N90 can, as long as not in the affected areas.
KN95 and KN90 who is good
The gb2626-2006 standard, non-oily Test (NaCl) particles having a diameter of 0.075 0.020m, KN95 filterability 95?KN90 filterability 90?viral droplets having a diameter of 1-5m
In summary, KN95 and KN90 have a protective effect against the virus droplets, KN95 better than KN90, choose.
How medical and surgical masks N/KN90 selection
Mask filter non-oily particles is not more difficult the smaller the particle filter, but a smile concave curve, the lowest point (the most difficult to filter) is 0.3 microns, of less than 0.3 micrometer (virus) or greater than 0.3 microns (bacteria/droplets) particle filtration efficiency of higher than 0.3 micron, the filtration efficiency of the mask under N/KN standards are measured on 0.3 micron particles.
N/KN95 can prevent 95?f 0.3 micron particles, N/KN90 can prevent 90?and is mainly used for medical surgical masks defense 3-5 microns bacteria (bacteria can withstand 95?r more), but only 20 efficiency against viruses -80?depending on the size of the virus, Document: Am J Infect Control, 2006, 34: 51-7)
Novel coronavirus size is 0.1 microns, less than 0.3 micrometer, so N/KN90 rejection mask must be 90?r more, this number is greater than 80?f surgical masks maximum efficiency defense.
However, there is no difference in efficiency we want so much, the virus spread mainly by droplets, droplet size between 1 and 10 microns, surgical masks for droplets of defense is still possible. The main disadvantage of surgical mask that is not bonded to the face and N/KN90 tight, protective effect for droplets suspended in the air or front emission weaker.
So, in general, N/KN90 defense more effective than surgical masks stronger.
knock! black! board!
How to wear a mask properly
1, hand and lift protective masks, nose clip has outwardly back side;
2, protective masks covering the nose, mouth and chin, nose clip portion abutting face upward;
3, with the other hand to pull the tie under the belt over the head, ears on the back of the neck;
4, with the top line and then pulled to the middle of the head;
5, the hands and fingers is placed on a metal nose clip, starting from the neutral position, the point by hand nose clips, and moving and pressing respectively on both sides, according to the shape of the nose shape of the nose clip.
How long you can use a mask?
Any type of masks, protective effects are time-sensitive and must be replaced periodically, it recommended every 2 to 4 hours to replace a mask. If the mask is contaminated, the first time should be replaced.
Such as industrial masks, usually under no circumstances can the epidemic three days, but given the current situation is recommended, or follow the doctor's, for a 4 hours, under normal circumstances, if you want to go out into the crowded places long day, prepare two masks almost.
There are a lot of people are going to take off the mask in his pocket, a chance to wear after a while, which does not work.
Best to wear, do not just take off, take off on a change, especially in the epidemic period, maintaining good hygiene is very important.
Where to buy?
Jingdong: Do not import than the flagship store to buy;
Taobao: Lynx do not buy, do not buy the SF spot, do not buy less comment, do not buy another business, C stores do not buy;
Fight a lot: all do not buy;
Circle of Friends: Do not buy all;
I wish you peace, an early end to the epidemic.
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