Medical masks

Medical masks

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. textile.

Constitute

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).

classification

According to performance characteristics and scope of application, medical masks can be divided into: medical protective masks, medical surgical masks, general medical masks.

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 and treatment activities. 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 GB19083-2003 "Technical Requirements for Medical Protective Masks" standards. Important technical indicators include non-oily particle filtration efficiency and airflow resistance. The specific indicators are as follows: [3]

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.

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 poses a threat to 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 distributed to prevent other hospital personnel from posing a threat of infection and reduce the risk of cross-infection, but to avoid infections less effective than medical protective masks.

It complies with the YY0469-2004 "Technical Requirements for Medical Surgical Masks" standard. 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.

Instructions

1. Cover the mouth and nose carefully with a mask and fasten it to minimize the gap between the face and the mask;
2. Avoid touching the mask during use-after touching the used mask, for example, to remove or wash the mask, wash your hands with soap and water or use alcohol hand sanitizer;
3. After the mask is wet or contaminated with moisture, put on a new clean and dry mask;

4. Do not reuse disposable masks, disposable masks should be discarded after each use.