How often do you change your n95 mask? A mask is expensive a day. How to change it is more appropriate?

What I say below is based on the current situation that the supply of combat masks is in short supply. One is expensive, and the other is scarce. Therefore, we can only "tighten our belts" and "make the best choice", which is also an extraordinary period and an extraordinary measure.

What is a N95 mask?

Simply put, N95 has two meanings. N is not oil-tolerant, the virus is non-oily particles and can be blocked. 95 is named for its dustproof effect, which means that it can block more than 95% of external particles, and pathogens such as viruses exist in the form of particles.

N95 is certified by National Institute of Occupational Safety and Health (NIOSH), and KN95 is available in the market, which is the standard of China, but it is almost the same.

Generally speaking, the continuous use time of the medical protective mask to which N95 mask belongs is 4-6 hours.

In view of the dilemma that masks are hard to find, as ordinary people, if they have never been to crowded places or hospitals and other places with high possibility of virus contact, they can appropriately extend the use time of N95 masks and use them repeatedly for 5 times.

The National Institute of Occupational Safety and Health (NIOSH) said:

N95 series masks can be reused as long as their structural and functional integrity are maintained and the filter materials are not physically damaged or polluted. However, hands must be cleaned before putting on the mask and after taking off the mask.

You just need to hang the mask in a ventilated and dry place and air-dry it for a while. It is difficult for novel coronavirus to survive in this environment for more than 1 hour.

But remember not to disinfect with water or alcohol spray, because this will destroy the adsorption barrier ability of the mask, so that the mask can not reach the protection ability.

Also, there are rumors that N95 masks can be blown for 30 minutes with a high-power hair dryer, hoping to be used repeatedly, which is also wrong. Because after this operation, the filterability of the fibers in the N95 mask will change and the protective effect will be damaged.

Note that if you wear N95 in close contact with infected people, it is not recommended to reuse it (but I believe that among my readers, there are very few cases of close contact with infected people).

In addition, the following knowledge is what you need to know:

Protective ability of mask: kn (n) 99 > KN(N)95 > Surgical mask > General medical > General mask > Do not wear it.

I'm talking about genes together. Welcome to pay attention. # Southern Health Super Group # @ Southern Health # Focus on New Pneumonia #

N95 of N95 mask is not a product name or a product model. N95 refers to the internationally accepted implementation standard and represents the level of particulate matter protection. "N" means oil resistance, "95" means exposure to a specified number of special test particles, and the particle concentration inside the mask is 95% lower than that outside the mask. Among them, 95% is not the average value, but the minimum value, so the average value of actual products is mostly set above 99%.

Most N95 masks are disposable consumables, especially for preventing infectious diseases caused by the spread of viruses, bacteria, fungi and other pathogens in the air. Unlike dust-proof, smog-proof and industrial dust inhalation, it cannot be used for a long time, otherwise bacteria may accumulate and multiply on the surface of the mask and eventually pollute the inside of the mask, resulting in a great decline in disease prevention efficiency. Whether it is an ordinary mask or an N95 mask, it should be replaced after 4 hours of continuous use, because the mask is full of harmful particles, and it will be inhaled by the human body if it is not replaced.

High temperature disinfection and cleaning are not allowed, and other disinfection is even more impossible. The key functional layer of N95 mask filtration is the middle layer of meltblown nonwoven fabric. When filtering by electrostatic adsorption of fine particles, the middle layer of meltblown nonwoven filter screen will be destroyed after high temperature disinfection and cleaning. Other disinfection methods are even more ignored, and any disinfectant is not safe for the mouth and nose. If you really want to extend the use time, it is safer to dry it directly with a hair dryer, because the survival rate of the virus is limited in a dry environment.

As we all know, droplets mainly spread in COVID-19. From the perspective of droplet isolation and prevention, as long as it is not in a key epidemic area, or medical personnel, frontline protection personnel, disposable medical surgical masks or disposable protective masks can play this role. Because, firstly, although N95 mask belongs to a higher level of protective mask, its protective effect is roughly equivalent to that of disposable medical surgical mask; Secondly, the price of N95 masks is really expensive, and changing them too frequently is really a big expense.

Hello, everyone, I'm a physician and I'm teasing on the Internet. The most scarce new year's goods this year are "masks". Even in the hospital, people are nervous, but some friends are lucky. They have the highest protection mask "N95". How to use such an expensive mask? How long will it take to change it? Please come here if you have this question!

First, masks, I am not a professional, but I can find professional evidence for you!

① Study on the protective efficiency and wearing time of medical protective mask.

Conclusion: The filtration efficiency of N95 mask is still above 95% after 2 days, above 90% after 6 days and above 80% after 14 days.

(2) This document lists the suggestions of the CDC of the United States on N95 masks during major epidemics, and there are suggestions for reuse in several epidemics.

③ In this document, the air tightness test of the mask is emphasized. A false sense of security is more dangerous!

Second, briefly talk about the N95 mask.

Many N95 masks are disposable consumables, especially when used to prevent infectious diseases caused by the spread of viruses, bacteria, fungi and other pathogens in the air. Otherwise, N95 mask may cause bacteria to accumulate and multiply on the surface of the mask, and eventually pollute the inner surface of the mask, resulting in a great decline in disease prevention efficiency, which is slightly different from smog prevention and industrial dust inhalation. In the latter case, the wearing time can be longer. So if it's for medical staff in the isolation area, I think it should be disposable. If you are an ordinary person and don't contact people who are suspected or diagnosed with coronavirus infection, the time in the group can be appropriately extended.

② I mentioned earlier that the time for ordinary people to wear N95 masks can be appropriately extended, so how can there be a degree? The wearing time of N95 mask depends on the time of microbial aggregation and proliferation, and there is a problem that the microbial breeding environment on the mask surface changes. The mask just taken out of the sealed bag is sterile, and there is not much microenvironment suitable for the growth of germs. With the extension of wearing time, the moisture exhaled by the human body and the dust particles attached to the external surface of the mask will meet at the mouth and nose outlet of the mask, and gradually form a culture suitable for the growth of bacteria. Therefore, the growth rate of bacteria on the surface of the mask will gradually accelerate with the improvement of the breeding environment, so it is most appropriate to discard the mask before the inflection point of accelerated growth of bacteria comes. It is estimated that this time should not exceed 4 hours, otherwise microorganisms can penetrate into the inner surface, causing bacteria on the inner surface of the mask to exceed the standard. For ordinary people, I think it is acceptable to use it for about 2 days, because if you wear it for a long time, you may not know whether it will work. Maybe because you've been wearing this mask for too long, you still think coronavirus is the highest protection.

Third, how to change it?

I think as long as I don't contact with suspected or confirmed patients, I can only wear ordinary surgical masks when I go out to buy food and do activities. Because N95 is expensive, it doesn't take much time to change it, so my suggestion is to use an ordinary surgical mask. Don't grab N95 masks, leave better epidemic prevention substances to frontline epidemic prevention personnel. At the same time, try to go out as little as possible and take good protection when going out. For example, it is safer to wear gloves when we go shopping, so we should hurry back.

In view of the current severe epidemic situation, wearing masks is an important measure to prevent virus infection. However, when masks are difficult to meet all the needs, masks become a scarce commodity. No masks are used in high-risk areas such as fever clinics and isolation wards in hospitals (of course, ordinary people will not enter the isolation ward area). We can appropriately extend the service life of masks (including the time and frequency of use) to maximize the value of masks and save the number of masks.

Under normal circumstances, it is recommended that disposable medical surgical masks be used for no more than 4-6 hours. The service life of N95 mask should not exceed 6-8 hours. For the general population, disposable medical surgical masks can be used, and N95 masks can be used for people who need to be in close contact with epidemic areas in Hubei or medical personnel who need to be in contact with high-risk groups.

In the Technical Guide for the Selection and Use of Masks issued by China CDC, the precautions for the preservation, cleaning and disinfection of masks are as follows:

1. If you need to use the mask again, you can hang it in a clean, dry and ventilated place or put it in a clean and breathable paper bag. Masks should be placed separately to avoid contact with each other and marked. Masks are for your own use only, and you can't cross-use them to avoid cross-infection.

2, medical standard protective masks can't be cleaned, also can't use disinfectants, cooking and other methods for disinfection.

3. Cotton masks can be cleaned and disinfected, and other non-medical masks can be used according to the instructions.

Disposable surgical mask is divided into three layers, inner absorption layer, core filter layer (middle layer) and outer waterproof layer. The prevention of virus infection mainly lies in the middle filter layer, which uses a special material-meltblown nonwoven fabric, or meltblown fabric for short. The main component is polypropylene, which is a film made up of many criss-crossing fibers piled up in random directions.

(Fina Electron Microscope WeChat official account announced their experimental process) An experiment was conducted to analyze whether disposable masks can be reused after disinfection. Their experimental method is:

1. Divide the common disposable surgical masks into four pieces: one as the control group, without any treatment, one soaked in 75% for one hour, one boiled in boiling water for 10 minute, and one steamed with steam for 7 minutes. Four samples were naturally dried, and the middle filter layer was taken out. The structure of meltblown cloth was observed by scanning electron microscope.

2. Experimental conclusion: Reasonable disinfection treatment, whether alcohol treatment or cooking, will not cause obvious damage to the macro and micro fiber structure of meltblown nonwovens, and alcohol spraying will not necessarily greatly reduce the filtering ability of the mask, but it does not mean that you can wear the sterilized mask with confidence and boldness.

PS: There are medical staff sharing SARS. Using 16 cotton mask can effectively prevent coronavirus infection.

At the same time, as my personal point of view, the mask should be thrown away, but it can be reused when it can be reused. For example, wear a mask for a while, go out to buy a dish, take out the garbage, and get a courier. In this case, it is ok to put the mask in a ventilated place to dry before use, but there is really no clear suggestion, that is, how long it must be used depends on the reserve of the mask and the actual situation of use. Now more often, there is no choice but to reuse the mask.

The above is only a personal opinion. The experimental reference was published by the official account of Fina Electron Microscope WeChat-"Can disposable masks be reused after disinfection? The experimental results of scanning electron microscope are published. If there are any mistakes, your suggestions and corrections are welcome.

In the face of the epidemic, wearing a mask can protect yourself and others well. Facing many masks, N95 masks are safer and more expensive. Wearing a mask is safe, but the mask has a certain use period, that is, after the use period, the safety will be reduced. Let's start with science. What is a N95 mask?

N95 is an American standard, and KN95 is a China standard, which all mean the same thing. N95 has two meanings: N is oil-intolerant, and the virus is non-oily particles, which can be shielded; 95 is named for its dustproof effect, which means that it can block more than 95% of external particles, and the virus exists in the form of particles.

It depends on the environment used. If it is used in an infected area like a hospital, it is recommended to replace it within one day, because the bacteria and viruses outside the mask and the structure inside the filter will exceed the standard. If you use it again, it will be very unsafe.

If you are shopping in the street, it is no problem to bring this safe environment for a few more days, but when you get home, you should hang it in a ventilated place and don't touch the outside of the mask with your hands.

If you have a mask to change, you can change it on time. If not, I advise you to save it and go out as little as possible! In particular, this N95 mask is reserved for medical staff, so don't buy it any more. Ordinary medical masks can also be used without infection!

Suddenly thought of a way, three disposable masks are worn at the same time, marked with layer 123, worn during the day and dried at night. Disinfect the outermost and innermost layers when they are dirty, wash them and dry them, and then use them again. The mask in the middle layer is only dry, not cleaned and disinfected! Prepare six masks (two sets) that can be used all the time! I hope it works!

1. Generally speaking, the continuous use time of medical protective masks belonging to N95 masks is 4-6 hours.

For details, please refer to the product manual or the precautions marked on the outer packaging.

2. As an ordinary person, if you have never been to a crowded place, or a place with high possibility of virus contact such as a hospital, you can appropriately extend the use time of N95 masks.

The National Institute of Occupational Safety and Health (NIOSH) said:

Note that if you wear N95 in close contact with infected people, it is not recommended to reuse it.

Of course, N95 masks are not easy to buy now, and there are many fakes. We also suggest that you leave the limited resources of medical protective masks to front-line medical staff.

What's more, relatively speaking, the higher the breathing efficiency, the greater the resistance will definitely be. In other words, the better the mask, the more difficult it is to breathe.

You still have to combine your own situation and don't need to pursue high-end masks too much.

For ordinary people, we advise you not to contact virus-infected people when you go out and use medical surgical masks. Medical nursing mask.

This kind of masks are basically disposable, and should not be worn for more than 4 hours (please refer to the precautions in the product manual or packaging labeling for details), and it is not recommended to use them repeatedly.

3. how to discard it?

When all the above masks are discarded after wearing, we suggest that you put them in a bag separately to avoid secondary pollution.

It is recommended to disinfect with alcohol, put it in a bag and seal it, and then throw it into the designated trash can. If there is no specially designated trash can, throw it into the harmful trash can.

I received a good news this morning that "the number of new cases outside Hubei has dropped for five consecutive days", which proves that the epidemic situation in China has been effectively controlled. It is really gratifying, and it does not waste the painstaking choice of our people to stay at home every day. Now that the battle is approaching the last critical moment, we should remain vigilant and not let the virus resurface.

However, it is at this critical moment that we are at the peak of returning work, which poses a great threat to the prevention and control of the epidemic. What is even more frightening is that the masks we hoarded years ago have almost disappeared, and now they are really hard to find. Now netizens are complaining about buying masks to find relationships. What we can do is to reuse disposable masks.

Although the protection level is very high, it is also a disposable product. After a long time of use, the bacteria attached to the mask will become the source of infection, and its filtration efficiency will become worse with the extension of use time;

Relevant literature shows that the filtration efficiency of N95 mask is still above 95% after 2 days, above 90% after 6 days and above 80% after 14 days.

First, the maximum service life of different types of masks is as follows:

①N95 mask

(1) If it is in a severe epidemic area, such as Wuhan, but it is not a medical worker, because it has been made clear that COVID-19 can be spread by "aerosol" suspended in the air, it is best to replace it in 1-2 days for safety.

(2) If it is in an epidemic-free area, or a small and open place, considering that the probability of encountering COVID-19 is still relatively small, the service life can be appropriately extended, and 3-4 days is relatively safe.

② Surgical masks: Academician Zhong said that you should wear masks when you go out, and it doesn't matter if you can't buy N95 masks. Ordinary medical surgical masks are also acceptable, and surgical masks are used in non-first-line departments where Dr. Lin works.

Although the protective effect of medical surgical masks on COVID-19 is similar to that of n95, the filtering efficiency of bacteria is over 95%, but the filtering efficiency of particulate matter is limited, and most of them are rectangular in design, which is not as tight as that of medical protective masks. Long-term use will affect the protection. If you are outdoors or in crowded places for a long time, it is generally recommended to replace it every four hours. If the mask is really lacking, it is recommended to use 1-2 days and replace it in time.

③ Disposable medical mask: Although the safety of this mask does not meet the anti-COVID-19 standard, it still has a certain protective effect, but even ordinary medical masks are hard to buy now, but it is recommended to replace them every four hours, and the longest service life should not exceed 1 day.

④ Other masks:

Cotton masks, activated carbon masks, and "PITTA" masks with the same model of stars have low filtration efficiency. But if you can't buy anything, it's better to wear it than not to wear it. Although the "net" of these masks is very thick, and the "mesh" is larger than the diameter of the virus, fortunately, it is not a "net", but a three-dimensional structure, just like you can enter a maze, but you may not be able to get out. Some viruses will eventually walk into a dead end and cannot get out.

These wearing times must be changed every 4 hours, because the filtering effect itself is poor, and long-term use is tantamount to "streaking" in the virus.

Second, how to disinfect the used mask: the mask can be sterilized by dry heat in an oven at 70 degrees Celsius for 30 minutes, or it can be sterilized by ultraviolet rays for 30 seconds. COVID-19 will be inactivated at 56 degrees Celsius in 30 minutes. Although ultraviolet rays are more bactericidal, they are rarely found in ordinary families.

Note: Never disinfect the mask with alcohol, because it will destroy the filtering effect of the mask.

Conclusion: Although N95 mask is the best protection against virus, there is still a shortage of front-line medical staff, so try to use surgical mask for protection. The resources of N95 masks have given a more needed line. Only when they are better protected, our campaign will end faster and the losses will be less. However, no matter how good the protection is, it can't guarantee that we won't be infected, so we should try not to go out and reduce the chance of infection.

The doctor said, I just asked the pharmacy this afternoon that alcohol should be disinfected every five days. That's all.

6-8 hours! But I don't think it's necessary to buy n95, medical masks and surgical masks!