Regarding masks, it is actually divided into several categories, so for users, they must wear masks correctly to achieve the intended purpose. This article will popularize mask knowledge and provide online purchase.
Basic knowledge of masks
1. No need for activated carbon masks (which usually look black), what’s the effect? Activated carbon is used to adsorb chemicals, which is used in chemical plants. Pneumonia mainly prevents dust and saliva spray;
2. The larger the number behind N95 / KN95 is, the higher the filtering level is; N95 is enough, but if you ca n’t buy N95 level, you need to use N90 level. If N90 does n’t have it, what masks and masks are better than that? Not good.
3. KN is Chinese national standard, which is similar to American standard; N is American standard, NIOSH, National Institute for Occupational Safety and Health, NIOSH
4. FFP3: It is a European standard. Any FFP3 grade particulate matter respirator certified by European standards can effectively filter 0.3 micron oily and non-oily particles with a filtration efficiency of at least 99%.
NIOSH certified other anti-particulate mask levels also include: N95, N99, N100, R95, R99, R100, P95, P99, P100, a total of 9 types. These protection levels can cover the protection range of N95.
“N” (not resistant to oil), suitable for non-oily particles, no time limit.
“R” (resistant to oil), suitable for oily or non-oily particles, if used for the protection of oily particles, the use time does not exceed 8 hours.
“P” (oil proof), suitable for oily or non-oily particles. If used for oily particles, the use time should follow the manufacturer’s recommendations.
“95”, “99” and “100” refer to the level of filtration efficiency when tested with 0.3 micron particles.
“95” means the filtration efficiency is above 95%,;
“99” means the filtration efficiency is above 99%;
and “100” means the filtration efficiency is above 99.7%.
Disposable medical masks
It is mainly used in high-demand medical environments such as medical clinics, laboratories and operating rooms, with a relatively high safety factor and strong resistance to bacteria and viruses.
Medical surgical masks can block particles larger than 4 microns in diameter. Tests conducted in a mask-enclosed laboratory in a hospital environment show that according to general medical standards, for 0.3 micron particles, the permeability of medical surgical masks is 18.3%.
Disposable medical masks are mostly made of one or more layers of non-woven fabrics. The main production processes include meltblown, spunbond, hot air or acupuncture. They are equivalent to resisting liquids, filtering particulates and bacteria. It is a medical Protective textiles.
Medical masks consist of a mask face and a tension band. The face mask is divided into three layers: inner, middle and outer. Fiber meltblown material layer), the outer layer is a special material antibacterial layer (non-woven fabric or ultra-thin polypropylene meltblown material layer)
According to performance characteristics and scope of application, medical masks can be divided into: medical protective masks, medical surgical masks, general medical masks.
1. Medical protective mask
Medical protective mask is suitable for the protection of airborne respiratory infectious diseases by medical personnel and related staff. It is a kind of self-adhesive filtering medical protective equipment with high protection level, especially suitable for contact with airborne transmission during diagnosis Or wear it for patients with respiratory infections that are transmitted by droplets at close range. It can filter the particles in the air and block droplets, blood, body fluids, secretion droplets, etc. It is a disposable product. Medical protective masks can prevent most bacteria, viruses and other pathogens. WHO recommends that medical personnel use protective masks against particulate matter to prevent virus infection in the hospital air.
Medical protective masks meet the standards. Important technical indicators include non-oily particle filtration efficiency and airflow resistance. The specific indicators are as follows:
1) Filtration efficiency: Under the condition of air flow rate (85 ± 2) L / min, the filtration efficiency for aerodynamic median diameter (0.24 ± 0.06) μm sodium chloride aerosol is not less than 95%, which is in line with N95 ( Or FFP2) and above. Can block airborne infection factors <5μm in diameter or close contact with droplet-borne infection factors.
2) Inspiratory resistance: Under the above flow conditions, the inspiratory resistance does not exceed 343.2Pa (35mmH2O).
3) The sample sprayed to the mask under the pressure of 10.9Kpa (80mmHg) should not have any technical indicators such as penetration inside the mask.
4) The mask must be equipped with a nose clip. The nose clip is made of a flexible plastic material with a length of> 8.5cm.
5) The synthetic blood is sprayed on the mask sample at a pressure of 10.7kPa (80mmHg), and the inside of the mask should not penetrate.
2. Medical surgical mask
Medical surgical masks are suitable for basic protection of medical personnel or related personnel, as well as protection against blood, body fluids and splashes during invasive operation. The protection level is medium and it has certain respiratory protection performance. It is mainly worn in a clean environment with a cleanliness of less than 100,000, operating in the operating room, nursing patients with low immune function, and performing body cavity puncture. Medical surgical masks can block most bacteria and some viruses, prevent medical staff from being infected, and prevent direct discharge of microorganisms carried by medical staff, which threatens patients undergoing surgery. Medical surgical masks require a filtration efficiency of more than 95% for bacteria. For suspicious respiratory patients, disposable medical surgical masks should also be dispensed to prevent the threat of infection to other hospital personnel and reduce the risk of cross infection, but to avoid infections that are less effective than medical protective masks.
Meet the standards, important technical indicators include filtration efficiency, bacterial filtration efficiency and respiratory resistance. The specific indicators are as follows:
1) Filtration efficiency: Under the condition of air flow (30 ± 2) L / min, the filtration efficiency for aerodynamic median diameter (0.24 ± 0.06) μm sodium chloride aerosol is not less than 30%.
2) Bacterial filtration efficiency: Under specified conditions, the filtration efficiency of Staphylococcus aureus aerosols with an average particle diameter of (3 ± 0.3) μm is not less than 95%; the filtration rate of bacteria should be ≥95%; The filtration rate should be ≥30%.
3) Breathing resistance: In the condition of filtering efficiency and flow rate, the inhalation resistance does not exceed 49Pa, and the exhalation resistance does not exceed 29.4Pa. When the pressure difference △ P for gas exchange on both sides of the mask is 49Pa / cm, the gas flow rate should be ≥264mm / s.
4) Nose clip and mask strap: The nose clip should be equipped with a nose clip made of a plastic material, and the length of the nose clip should be greater than 8.0cm. Mask strips should be easy to wear, and the breaking strength at the connection point between each mask strip and the mask body should be greater than 10N.
5) Synthetic blood penetration: After 2ml of synthetic blood is sprayed on the outer side of the mask at a pressure of 16.0kPa (120mmHg), the inner side of the mask should not penetrate.
6) Flame retardant performance: Non-flammable materials should be used for mask materials, and the mask will burn for less than 5s after leaving the flame.
7) Ethylene oxide residue: Ethylene oxide sterilized masks should have less than 10 μg / g of ethylene oxide.
8) Skin irritation: The primary irritation index of the mask material should be ≤0.4, and there should be no allergic reaction.
9) Microbiological indicators: The total number of bacterial colonies is ≤20CFU / g. Coliform bacteria, Pseudomonas aeruginosa, Staphylococcus aureus, hemolytic streptococcus and fungi shall not be detected.
3. General medical mask
Ordinary medical masks are used to block the spray from the mouth and nasal cavity. They can be used for disposable sanitary care in the ordinary medical environment with the lowest protection level. Suitable for general health care activities, such as sanitary cleaning, dosing, cleaning bed units, etc., or the blocking or protection of particles other than pathogenic microorganisms such as pollen.
It meets the relevant registered product standards (YZB), and generally lacks the filtration efficiency requirements for particles and bacteria, or the filtration efficiency requirements for particles and bacteria are lower than medical surgical masks and medical protective masks, and only reach 20.0% for aerosols with a diameter of 0.3 μm -25.0% protection effect, can not reach the filtration efficiency of particles and bacteria, can not effectively prevent pathogens from invading through the respiratory tract, can not be used for clinical invasive operations, can not protect particles and bacterial viruses, only limited to dust particles Or aerosol plays a certain mechanical barrier.
Medical protective mask
Medical protective masks refer to self-absorbent filtering dust-proof medical protective products that can filter airborne particles, prevent the spread of certain respiratory infectious microorganisms, and block droplets, blood, body fluids, secretions, etc
Medical protective mask A mask capable of preventing infection through air-borne diameter ≤5μmg infectious factor or close-range (≤1m) contact with droplet-borne diseases. The use of medical masks includes tightness testing, training, model selection, medical handling and maintenance.
The medical protective mask is composed of a mask face and a tension band. The face mask is divided into inner, middle and outer layers. The inner layer is ordinary sanitary gauze or non-woven fabric. The middle layer is a superfine polypropylene fiber meltblown material layer and the outer layer. Non-woven fabric or ultra-thin polypropylene meltblown material layer. This highly effective medical protective mask is highly hydrophobic and breathable, and has a significant filtering effect on tiny virus aerosols or harmful dust. The overall filtering effect is good, the materials used are non-toxic and harmless, and they are comfortable to wear.
It can prevent infections caused by airborne diameter ≤ 5μmg infectious agents or close-range (≤ 1m) exposure to droplet-borne diseases. The particle filtering efficiency of the mask filter should be not less than 95%, and the protection level is high
Medical protective masks are better protective equipment. It is recommended to wear them when there is serious environmental pollution or medical infectious diseases (such as respiratory infections).
(1) Protection of airborne particles from harm to human body
(2) Protection for medical personnel in infectious disease areas
(3) Protection for virus laboratory personnel
(4) Protection of various personnel during the epidemic
(5) Toxic chemical, mining staff, allergic to pollen
(6) Individual protection of military biochemical weapons
Important technical indicators
Including non-oily particle filtration efficiency and airflow resistance.
(1) Filtration efficiency: Under the condition of air flow rate (85 ± 2) L / min, the filtration efficiency for aerodynamic median diameter (0.24 ± 0.06) μm sodium chloride aerosol is not less than 95%, which is in line with N95 (Or FFP2) and above.
(2) Inspiratory resistance: under the above flow conditions, the inspiratory resistance does not exceed 343.2Pa (35mm H2O)