Nowadays, masks are becoming more and more popular, mainly because air pollution is getting more and more serious. People must use masks to protect their breathing more healthily when smog approaches, and n95 masks are also on fire during this period. So can n95 masks really prevent smog?
What is N95 mask In NIOSH's revised respiratory protection certification rules (42 CFR 84), "N95" actually describes the filter material grade, not the mask/gas mask itself (mask/gas mask is a word in English). However, many well-known masks are N95 filter materials, also called "N95 masks". So what does "N95" stand for?
In NIOSH test, the filter material that can filter out more than 95% of suspended particles in the air is given "95" grade, more than 99% is "99" grade, and 99.97% (substantially equal to 100%) is "100" grade. The letters N, R and P represent the resistance of the filter material to suspended oil droplets in the air (some oil will reduce the filtration efficiency of the filter material), N represents that it can't be stopped at all, R represents small resistance, and P represents large resistance. In this way, the following table can be obtained:
Grade description
N95, N95, N99 and N 100 can filter out at least 95%, 99% and 99.97% of suspended particles, and are not oil-resistant.
R95, R95, R99 and R 100 can filter out at least 95%, 99% and 99.97% of suspended particles, which are somewhat oil-resistant.
P95, P95, P99, P 100 can filter out at least 95%, 99% and 99.97% of suspended particles, which are quite oil resistant.
In other words, the actual meaning of "N95" is: the filter material grade that can filter at least 95% of suspended particles in the air, but is not resistant to oil.
PS: NIOSH tests the filter media by simulating the "worst case" parameters, such as using particles with the strongest penetration to the filter media with a diameter of about 0.3 microns, simulating the gas flow rate of 85 L/min under high working intensity, and electrically neutral aerosol (which is not conducive to electrostatic adsorption of suspended particles by the filter media). In any link of the test, the filtering speed shall not be lower than the lowest filtering speed of the grade, and then the corresponding grade shall be evaluated. That's quite strict!
Is the common medical mask N95? The answer is no, ordinary medical masks are not specially designed to resist suspended particles, and the protection efficiency is not as good as N95 masks. Ordinary medical masks are used to block large particles (such as bacteria). Most of them have no effect on tiny suspended particles (such as PM2.5), and users will leak from the side when breathing.
Do N95 masks come in different sizes and styles? Yes, and there are many. If the mask doesn't fit your face properly, it will easily leak when you breathe, and polluted air will come in from there, so you have to try and choose the size and style with the highest synchronization rate with you.
I have a sexy beard. Is the N95 mask still usable? Anything that prevents the mask from fitting my face, such as long beard and beard, will cause your mask to leak (close your eyes with tears). If your mask needs to fit your face tightly to seal it, you'd better shave your beard. If you are smart enough, you can grow a beard with a filter device that can cover your whole head (such as Resident Evil's).
PS: The American Institute of Occupational Protection is very thoughtful. ...
Can anyone protect themselves with a mask? No, breathing with a mask is much more difficult than breathing freely. People with lung diseases, such as asthma, emphysema and the elderly, may be in trouble. In short, it is best to consult a doctor before using it.
Does n95 mask prevent smog? This paper takes the well-known mask brand 3N95 as an example for analysis.
KR and KN series commonly use 3M masks: KR series can filter oily particles, while KN series mainly filters non-oily particles, but cannot filter oily particles.
Filtration index: 95 series can filter 95% of particles, and 90 series can filter 90% of particles.
To sum up, for example, N95 masks refer to KN series, and the filtration index is 95%. PS: Some mask models contain activated carbon (usually gray in color). The function of activated carbon is to filter unpleasant smells. In Beijing, the 95 series is better, after all, the filtration index is higher. (For children's shoes with insufficient money, it is better to wear 90 series than not to wear them ~) Generally, there are both non-oily particles and oily particles in the smog (there are oily particles in automobile exhaust). As for choosing KR or KN series (KR series will be more expensive), it can be decided according to demand and money ~
List a few I often wear, for reference only:
82 10 and 90 10, which are series 95;
9005, 90 series.
82 10: cannot be folded; Thick (almost as thick as ordinary cotton masks); There is a sponge on the nose, so it has good sealing performance; Generally 4 ~ 6 yuan/piece.
90 10/0,9005: foldable, easy to put in bags and pockets; Thinner than 82 10 (almost as thick as hospital masks); There is no sponge in the nose, and the sealing performance is not as good as 8210; Average 1.5 ~ 4 yuan/piece.
PS: 1, I found that the price of masks soared with the increase of people's attention. . . tears gushing from one's eyes
2. When wearing a mask, please pay attention to wearing it tightly (such as whether it is completely close to the face and whether the nose is tight).
I recommend buying address: Amazon, Zhuo Yue: cheap, reliable in quality and fast in delivery. Official flagship store of 3M on Taobao: reliable quality, no promotion price is higher than Amazon, and express delivery is not as fast as Amazon. The following is a detailed classification of 3M masks. Interested children's shoes can look at:
(1): N 95 series (less than ten times, unlimited times) 82 10 dustproof, 851with valve, 85 15 with electric welding valve, 85 12 with electric welding valve.
(2): N 100 series (same as above for non-oil products, used below ten times the standard, toxic metals such as aluminum, cadmium, arsenic and radioactive particles, pharmaceutical industry, etc.). The filtration efficiency exceeds 99.7) 8233 with valve.
(3): R 95 series (10 times or less, oily environment for 8 hours, non-oily until breathing is blocked) 8247 organic vapor odor and particles contain carbon, and 8246 acid gas and particles contain carbon.
(4): P 95 series (less than 10 times, oil for 40 hours, without oil until it is blocked) 8577 odorous organic vapor and carbon-containing particles with valves, 8576 acid gas and carbon-containing particles with valves.
(5): 9000 is the standard of 900 1A/9002A, 9003A /9004A is medium and small, 902 1 /9022 is durable, and 904 1A /9042A contains carbon.
(6): FFP 1 series particle protection (European standard, environmental protection test with 0.3 micron particle size of 95 liters/minute, more than 80% filtration, used in mine casting, polishing, textile and agriculture, etc. )8200C。
(7): FFP 2 series particle protection (European standard, the filtration efficiency is more than 94%, used for very fine industrial dust, suitable for damp heat and long-term wear) 8822 with valve, 9320 foldable.
(8): FFP3 is highly toxic protection (European standard, more than 99% filtration, used for highly toxic and radioactive particles, welding metal fumes, etc. , suitable for damp heat and long-term wear), 9332 with valve.
I heard that Germany stipulates that n95 series workers must take off their masks and breathe normally for half an hour after wearing them, otherwise it will damage the respiratory system?
I am quite ignorant. I haven't heard of this statement, but wearing a mask is definitely not as good as breathing smoothly without a mask. If this is implemented: German workers wear masks for half an hour in the factory, and then they can go outside the factory to breathe fresh air for half an hour; And we have been wearing masks for half an hour under normal circumstances. If we take off our masks, where should we go to breathe fresh air for half an hour? If you can only breathe very poor quality air after taking off the mask, forget it. What am I wearing a mask for ~ ~ Breathing poor air will damage the respiratory system! !
N95 became popular in the extraordinary period of SARS in 2003, and a medical protective mask similar to a gas mask became the darling of the market. Compared with the first two masks, this kind of protective mask is much more professional in dust prevention. N95 mask models refer to American standard, and medical protective masks are divided into three categories and nine models. N stands for non-oily particles, and R and P stand for oily particles. Non-oily particles include coal dust, cement dust, acid mist, welding dust, microorganisms, etc. Oily particles include oil mist, oil fume and coke oven smoke. Each model is divided into three filtration efficiency grades, which are 95%, 99% and 100% respectively. N95 means "dust mask with 95% efficiency of filtering non-oily particles". China's standards for dust masks are not so detailed, but N95 is still the minimum standard for such dust masks.
At present, it is considered that the particulate matter in the atmosphere is the inhalable particulate matter (PM 10) with a diameter below10 micron, especially the particulate matter (PM2.5) with a diameter below 2.5 micron that can enter the lungs. For these tiny particles, the filtering effect of N95 is worthy of recognition. According to the production standard of N95, sodium chloride aerosol with a diameter of 0. 1-0.5 micron is the detection sample of particulate matter, and the filtration rate of qualified N95 mask should be above 95%. Therefore, if we wear a dust mask above N95 correctly, even if the air quality index (AQI) reports serious pollution, we can feel a little more at ease when going out.
When wearing a medical protective mask, it should be fitted to the face, and the inside of the mask should be kept closed to play a good filtering function. Breathing and inhalation tests should be carried out after wearing to confirm that there is no air leakage. The protective mask can be reused, but if any part of the mask is broken, broken, lost or the resistance increases when breathing, it should be replaced. Dust masks are not washable and should be discarded after elimination.
The above is what Bian Xiao shared for everyone about "Can n95 masks prevent smog, and can n95 masks prevent pm2.5?" I hope it will help everyone.