Basic knowledge of masks all we should know
Masks (hygiene items used to filter air entering the nose and mouth) Edit Discussion 99+ Upload videoRespirator is a kind of hygiene products, generally refers to the mouth and nose is used to filter the air into the nose and mouth, in order to achieve the role of blocking harmful gases, odors, droplets, viruses and other substances, made of gauze or paper.
Masks have a certain filtering effect on the air entering the lungs. When respiratory infectious diseases are prevalent and when working in a polluted environment such as dust, wearing a mask has a very good effect.
Masks can be divided into air filter masks and air supply masks [1].
Official Guidelines for Wearing Masks Scientifically
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China has exported more than 12 billion masks to the US
Recently, Wang Yi said: We have provided convenience and support for the US side to purchase in China, and exported more than 12 billion to the US side with only one mask, which is equivalent to providing nearly 40 masks for each American. But it is regrettable that in addition to the raging of the new crown virus, there is also a political virus that is spreading in the United States. This political virus is to use all opportunities to attack and discredit China. ... details
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Chinese name mask foreign name face mask; antiseptic gauze; gauze mask classification air filter mask and air supply mask material fabric, filter (melt blown cloth), non-woven fabric and other functions to prevent or reduce air dust into the respiratory organs Pinyin kǒuzhào
table of Contents
1 A brief history of development
2 Specifications
3 Medical or not
4 Item classification
▪ Air-supply mask
▪ Air filter mask
5 Selection method
▪ Dust suppression efficiency
▪ Degree of closeness
▪ Comfortable to wear
▪ Discomfortable people
6 Introduction to filter media
▪ Mask filter material
▪ Fit effect
7 Change the mask
8 Production materials
9 Notes
▪ Duration
▪ Cleaning and maintenance
▪ Proper handling
10 Cases of fraud
A brief history
Jin Yi "Follow the Old Horse": "At this time, he told me to pull the mask up and cover his nose so that Fei Hua could not get into the nostrils."
Official Guidelines for Wearing Masks for Public Science
Official Guide for Wearing Masks for Public Science [2]
The first mask in the world was China. In ancient times, in order to prevent dust and tone pollution, people in the palace began to cover their noses and noses with silk scarves, as stated in "Li Shu": "cover your mouth, and fear will touch people." If it is unclean, everyone will cover their noses. "It is unhygienic to cover your nose with your hands or sleeves, and it is not convenient to do other things. Later, someone used a silk cloth to cover your nose and nose. In his book "Marco Polo's Travels", Marco Polo describes his experience of living in China for 17 years. There is one of them: "In the Yuan Dynasty palace, all the people who donated food covered their mouths and noses with silk cloth, so as not to touch the food and drink." The silk cloth with such mouth and nose is the original mask.
In the early 13th century, masks only appeared in the Chinese court. The waiter used a silk and gold thread to make a mask to prevent his breath from reaching the emperor's food.
At the end of the 19th century, masks were used in the field of medical care. German pathologist Ledch began to recommend medical staff to use gauze hoods to prevent bacterial infections
For the first time in the 20th century, masks became a must-have for people's lives. The Spanish flu that has swept the world has claimed the lives of about 50 million people, and ordinary people are required to use masks to protect against the virus.
In the middle and late 20th century, the large-scale use of masks was obviously frequent. The masks that have been recorded in history have played an important role in preventing and blocking the spread of germs several times.
In March 1897, the German Medtech introduced to everyone a method of covering the mouth and nose with gauze to prevent the invasion of bacteria. Later, someone made a six-layer gauze mask, sewed on the collar, and turned it over to cover the nose and mouth when using it. However, this type of mask has to be held by hand, which is extremely inconvenient. Later, someone came up with a method of tying the straps to the ears, which became the mask that people often use today.
In 1910, a plague broke out in Harbin, China. At that time, Dr. Wu Liande, deputy supervisor of Beiyang Army Medical College, invented the "Wu mask".
In 2003, the use and popularization of masks reached a new climax. A SARS almost made the masks out of stock. A long line of people stood in front of major drugstores, and people rushed to buy masks.
In 2009, after the "avian flu" in 2004, the "type A H1N1 flu" made the army of masks once again appear in front of the world's major news media.
The emergence of the PM2.5 air hazard concept in 2013 triggered public attention to air pollution issues, making masks and other protective equipment very popular during smog.
On February 7, 2020, at the Disinfection Supply Center of the Second Affiliated Hospital of Xi'an Jiaotong University, more than 30 medical staff and volunteers used medical packaging nonwoven fabrics, absorbent paper for instruments, N95 meltblown filter cloths and other materials to make masks. [3]
Specifications
Planar masks are divided into: cotton masks, non-woven fabric masks, polymer material masks, activated carbon powder filter masks, activated carbon fiber felt pad masks.
Size specification: 18 × 9 (adult), 15 × 9 (child).
Medical or not
Masks are divided into medical masks and non-medical masks, (and the latest) civil sanitary masks.
At present, China's mask standards mainly regulate civil protection and medical protection. Standards for civil protective masks GB / T 32610-2016 "Technical Specifications for Daily Protective Masks", GB 2626-2006 "Respiratory Protective Products Self-Suction Filtering Anti-Particle Respirator", mainly applicable to the protection of particulates It plays an important role in the process, but the barrier masks (mainly flat masks) that are widely used in the resumption of production cannot meet the requirements of the above two standards. The medical standards GB 19083-2010 "Technical Requirements for Medical Protective Masks", YY 0469-2011 "Medical Surgical Masks", YY / T 0969-2013 "Disposable Medical Masks" are mainly applicable to medical institutions. However, there are no suitable standards for hygienic (barrier type) masks used by ordinary people according to the mask usage scenarios and the crowd. In order to better meet the urgent needs of the public for hygienic masks during the epidemic situation, it is convenient for enterprises that produce / convert masks to adopt and apply standards, and at the same time ensure product quality and facilitate market supervision. The market conducted an argumentation study and urgently submitted an application for the establishment of the "Civil Sanitary Mask" group standard to the Standardization Technical Committee of the China National Textile and Apparel Council (China Textile Federation). On March 11, the Chinese Communist Party Association officially released the T / CNITA 09104-2020 "civil sanitary mask" standard. [4]
Item classification
N series: no time limit for protection of non-oily suspended particles
R series: protection of non-oily suspended particles and sweaty oily suspended particles for a period of eight hours
P series: no time limit for protection of non-oily suspended particles and sweaty oily suspended particles
When the carrier of some particulates is oily, and these substances are attached to the electrostatic non-woven fabric, the electrical properties will be reduced, and the fine dust will penetrate. Therefore, the filter material for preventing the oil-containing sol must undergo special electrostatic treatment to achieve the anti-fine The purpose of dust. So each series is divided into 3 levels: 95%, 99%, 99.97% (that is, referred to as 95, 99, 100), so there are 9 small categories of filter materials.
2. European Union EN149 Standard:
FFP1 category mask: minimum filtering effect "80%
FFP2 mask: minimum filtering effect> 94%
FFP3 category mask: minimum filtering effect "97%
3. Australian AS1716 standard
P1: Minimum filtering effect "80%
P2: Minimum filtering effect "94%
4. Japanese MOL verification standards:
According to the Decree No. 0207006 issued by Japan on February 7, 2005, the standard of dust masks is as follows
Test environmental conditions
Experimental particles
DOP (liquid)
NaCl (solid)
Particle size distribution μm
0.15-0.25
0.06-0.1
Experimental concentration [mg / m3]
≤100
≤50
Experimental flow rate [L / min]
85
85
Test time
Total supply 200mg
Total supply 100mg
Replacement dust mask standard
distinguish
Filtration efficiency [more than%]
Inspiratory pressure [Pa or below]
Exhaust pressure [below Pa]
DOP
NaCl
RL3
RS3
99.9
160
80
RL2
RS2
95.0
80
70
RL1
RS1
80
70
70
Disposable mask standard
distinguish
Filtration efficiency [more than%]
Inspiratory pressure [Pa or below]
Exhaust pressure [below Pa]
DOP
NaCl
With air valve
Airless valve
With air valve
Airless valve
DL3
DS3
99.9
150
100
80
100
DL2
DS2
95
70
50
70
50
DL1
DS1
80
60
45
60
45
5. Chinese National Standard GB6223-86UDC614.894:
Except for the Japanese standard (0.06-0.1 microns), the above inspection standards are tested with a particle size of 0.3 microns.
The EU standard test flow rate is 95L / min, and the US standard is 85L / min. China's national standard uses a suspended particle size of more than 90% of less than 5 microns, more than 70% of less than 2 microns, and a flow rate of 42.5L / min. In the testing and certification of filter media, the "worst case" idea is adopted, that is, the conditions when the laboratory performs the testing experiment are set to the worst conditions. For example, when the efficiency experiment is used, the particle size of the aerosol sodium salt or DOP oil mist is 0.3 microns, and it represents the diameter of the aerodynamic calculation. It represents the size of the very small and most easily penetrated filter material. The breathing volume during strong physical labor, the filter material is also pre-treated at high temperature and high humidity before the experiment, which represents a harsh working environment. The purpose of all these is to test under such harsh conditions, if the filter material can pass the test Reaching the corresponding efficiency level, then in practical applications, it will be able to protect the health of workers more effectively. Anti-toxic filter materials generally use activated carbon or chemically-treated activated carbon as a material, and filter poisonous gas or poisonous vapor by adsorption or chemical reaction without being inhaled by people. There are many micropores in the internal structure of activated carbon that can constitute a very large specific surface area. These micropores can inhale toxic vapors and toxic gas molecules with different molecular sizes into them without escaping. The treatment and installation requirements of activated carbon are very high. If the improper treatment or the activated carbon particles are very thick and cause gaps between the particles, the poison gas will penetrate into the respiratory tract from the gaps and will not be adsorbed. Therefore, it is very unscientific to replace the activated carbon in bags. The activated carbon in a good chemical filter box should be packed densely, with a small particle size and a large specific surface area, so that the anti-virus time will be long. At the same time, it must also consider the small breathing resistance and comfortable wearing.
Air-supply mask
It refers to the clean air source isolated from harmful substances, which is sent to the person's face through a tube and a face mask for breathing through dynamic actions such as air compressors and compressed gas cylinder devices.
Air filter mask
Air filter masks are the most widely used in daily work. The structure of an air filter mask should be divided into two parts, one is the main body of the mask, which can be simply understood as a mask frame; the other is the filter material part, including dustproof filter cotton and antivirus Chemical filter box, etc.
Selection method edit
Dust suppression efficiency
The dust blocking efficiency of the mask is based on its blocking efficiency for fine dust, especially for respiratory dust below 2.5 microns. Because this size of dust can directly enter the alveoli, it has the greatest impact on human health.
Mask
Masks (3 photos)
Gauze masks, the principle of dust suppression is mechanical filtration, that is, when the dust hits the gauze, it passes through layers of barriers, blocking some large particles of dust in the sand cloth. For some fine dust, especially the dust smaller than 2.5 microns, it will pass through the gauze mesh and enter the respiratory system. Dust masks are composed of filter material activated carbon fiber felt pads or non-woven fabrics. Those breathable dusts less than 2.5 microns are blocked during the process of passing through this filter material, which plays the role of filtering air.
Tightness
The anti-leakage design of the mask is to prevent air from being sucked through the gap between the mask and the human face without filtering through the technical considerations. Air is like water flow, wherever resistance is small, it flows first. When the shape of the mask is not close to the face, the dangerous objects in the air will leak into the airway from the non-closed place. Then, even if you choose a mask with the best filter material. Nor can it protect your health. Many foreign regulations and standards stipulate that workers should regularly conduct mask adhesion testing. The purpose is to ensure that workers choose a mask of the appropriate size and wear the mask in the correct steps.
Comfortable to wear
In this way, workers will be happy to insist on wearing in the workplace and improve their work efficiency. Current maintenance-free masks abroad do not need to be cleaned or replaced. When the dust barrier is saturated or the mask is damaged, it is discarded. This not only ensures the hygiene of the mask but also saves the time and effort of the worker to maintain the mask. Moreover, many masks adopt an arch shape, which can not only ensure a good adhesion with the shape of the face, but also reserve a certain space at the mouth and nose, which is comfortable to wear.
Uncomfortable people
People with heart or respiratory problems (such as asthma and emphysema), pregnancy, dizziness after wearing, difficulty breathing, and sensitive skin.
Filter profile editor
Mask filter material
For the filter material of a good protective mask, the following three conditions should be met. First, the filter efficiency is high when the mask is close to the user's face, second, the respiratory resistance is small, and third, the user feels comfortable. There are many kinds of materials for dust masks, including ordinary fabrics, animal hair, non-woven fabrics, etc. Activated carbon felt material is very popular in the national standard.
The structure of the gauze mask is poorly adhered to the human face. Many small particles that are extremely harmful to us will enter the respiratory tract to the lungs through the gap between the mask and the face. The only way to achieve high dust resistance is to increase the thickness, and the negative effect of increasing the thickness is to make the user feel that the breathing resistance is very large and uncomfortable. The non-woven fabric after electrostatic treatment can not only block large dust particles, but also the static charge attached to its surface can attract fine dust through electrostatic attraction, achieving a high dust suppression efficiency. The thickness of the filter material is very thin, which greatly reduces the user's breathing resistance and feels comfortable, thus achieving the three necessary conditions of the good filter material we mentioned earlier. With a good filter material and a scientifically designed mask structure, an efficient and high-quality mask is formed.
Fit effect
The mask must be the right size and the way it is worn must be correct for the mask to be effective. Masks on the market are generally divided into two types, rectangular and cup-shaped. A rectangular mask must have a structure of at least three layers of paper in order to have a protective effect. The user needs to press the iron wire on the mask against the bridge of the nose, and then spread the entire mask along the bridge of the nose in order to exert the effect. Let the child wear a rectangular surgical mask because it has no fixed shape, and if it is tied well, it can be close to the child's face. Cup-shaped masks must ensure that the masks have sufficient density after they are attached to the face, so that the exhaled air will not leak out to be effective. When wearing a cup-shaped mask, you can try to blow by covering your mask with both hands.
Check for air leakage from the edges of the mask. If the mask is not tight, reposition it before wearing it.
Change mask edit
1. The mask is contaminated with foreign objects such as blood stains or droplets.
2. The user feels that the breathing resistance becomes greater.
3. The mask is damaged.
4. Dust-proof filter cotton, when the mask is close to the user's face, when the user feels a lot of breathing resistance, it means that the filter cotton is full of dust particles, and a new mask should be replaced.
5. Anti-virus filter box, when the mask is in close contact with the user's face, when the user smells the poison, it should be replaced with a new one.
6. Ordinary mask wear: activated carbon masks can generally be used for 2 days, n95 can be used for a week. If the mask has not been worn for a long time after cleaning, it is better to wear it again.
Production material editor
2-layer mask: non-woven fabric, nose bridge, ear hook.
3-layer mask: non-woven fabric, nose bridge, earhook, filter paper.
Activated carbon masks: non-woven fabric, nose bridge, ear hooks, filter paper, activated carbon filter paper.
Notes edit
Duration of use
From the point of view of human physiology, blood circulation in the nasal mucosa is very strong, and the channels in the nasal cavity are very tortuous. The nose hairs constitute a filtering "barrier". When air is sucked into the nostrils, the airflow forms a vortex in the tortuous channel, which heats the airflow sucked into the nasal cavity. Some tests have shown that when cold air at minus 7 ° C is drawn into the lungs through the nasal cavity, the airflow has been heated to 28.8 ° C, which is very close to the temperature of the human body. If you wear a mask for a long time, the nasal mucosa will become fragile and lose the original physiological function of the nasal cavity, so you cannot wear a mask for a long time. Masks can only be worn in special environments, such as places with many people and no air circulation. Of course, walking in the wild, in order to resist wind and sand and cold, or activities in an environment with air pollution, you need to wear a mask, but the time should not be too long. In addition, in the flu season, go to public places where there may be a large number of pathogens, you should also wear a mask. Wearing a mask is only one of the ways to prevent respiratory infectious diseases. The most important thing is to maintain good living habits.
Cleaning and maintenance
The outer layer of the mask often accumulates a lot of dust, bacteria and other dirt in the outside air, and the inner layer blocks the exhaled bacteria and saliva. Therefore, the two sides cannot be used alternately, otherwise the dirt contaminated by the outer layer will be directly attached When inhaled into the body, it becomes a source of infection. When the mask is not worn, it should be folded and placed in a clean envelope, and the side that is close to the nose and nose should be folded inwards. Do not stuff it into your pocket or hang it around your neck.
Daily use of masks must be properly handled
Daily use of masks must be properly handled
If the mask is wetted by exhaled heat or saliva, its effect of blocking germs will be greatly reduced. Therefore, it is best to prepare a few more masks for replacement. You should change and wash it once a day. When washing, it should be scalded with boiling water for 5 minutes.
Masks should be cleaned and disinfected every day. Both gauze masks and air filter masks can be disinfected by heating. The specific approach is:
1. Cleaning. First, gently rub the gauze mask with warm water and soap. The bowl-shaped mask can be gently brushed with a soft brush dipped in detergent, and then washed with water. Please be careful not to rub hard, because if the gap between the warp and weft of the gauze is too large, it will lose the effect of preventing droplets.
2. Disinfect. Put the cleaned mask in a 2% peracetic acid solution for 30 minutes or boil in boiling water for 20 minutes or steam in a steamer for 15 minutes, and then dry it for use. This method is suitable for gauze masks and bowl masks.
3. Check. Before using it again, you should carefully check whether the masks and masks are still intact. For gauze masks and masks, you can take a light transmission inspection method, that is, take a look in front of the lamp to see if there are obvious light spots. Is the rate consistent? If in doubt, replace it with a new one. In any case, masks and masks are generally updated after 3 to 7 times of cleaning, and masks of particularly good quality can be cleaned 10 times. Activated carbon adsorption masks should pay attention to regularly replace the activated carbon interlayer. If the activated carbon interlayer is not replaceable, it will be replaced after 7 to 14 days. This mask cannot be cleaned and then reused. [5]
Properly handled
Daily use of masks should be properly handled. Masks used by patients or used during care should be placed in a lined container in the patient room before being processed. [6]
Fake case editor
Fake mask
In February 2020, some vendors bought 6 cents of fake and inferior masks for distribution, and finally sold them at a price of 3 yuan each; there were also vendors who sold 1.06 million fake and inferior masks in half a day It sold out and made a profit of 450,000 yuan.
These fake and inferior masks have obvious quality problems, only a thin layer, the quality is poor. This is the critical period for epidemic prevention and control. Wearing fake masks will bring great security risks. The fake masks mentioned above all have the same name-"Piaoan". At present, fake "Piaoan" masks have appeared in many places across the country.
Henan Piao'an Company, which produces regular "Piao'an" masks, is located in Changyuan County, Henan Province, which is one of the three Dawei material bases in China. Since January 28, Henan Piaoan Group Co., Ltd. ’s WeChat public account has issued four solemn statements, saying that fake and shoddy masks on the market are not their production, and consumers are required to report in time.
Statistics show that up to now, Qingdao, Jining, Rizhao, Linyi, Dazhou, Yibin, Zigong, Nanchong, Sichuan, Benxi, Huangshan, Feidong, Guzhen, Liaoning, Linxia, Gansu, Putian, Fujian, Yangzhou, Jiangsu, Luohe, Nanyang The market supervision departments of Chibi, Hubei, Changsha, Yiyang, Hunan, and Huangpu, Shanghai have all intervened in the investigation and handling of fake and inferior masks that are counterfeiting "Henan Piaoan". [7]
Three without masks
In February 2020, Sichuan Neijiang seized more than 500,000 San Wu masks. The Hubei Xiantao suspect Guo Moumou and Neijiang woman Liu Moumou purchased and sold "three noes" through the Internet without the relevant qualifications. When entering the Neijiang area, the mask was actively blocked by the police after being reported by the masses, and the case was investigated according to law for the crime of selling medical devices that did not meet the standards. [8]
Fake masks
On February 27, 2020, a reporter from the Economic Observation Network learned from many insiders: Li Dong, chairman of Beijing Jinghai Kangbaixin Pharmaceutical Co., Ltd. (hereinafter referred to as Kangbaixin Company), a well-known large-scale pharmacy chain in Beijing, was suspected to be in When the new pneumonia epidemic broke out in 2020, "Knowing Fake Traders" bought more than 580,000 counterfeit 3M masks for illegal gains and was investigated by the Beijing police a few days ago. The 22 persons involved, including Li Dong, have been arrested by the public security organ.
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