Introduction of N95 Mask

Introduction of N95 Mask

The N95 mask is one of nine particulate protective masks certified by NIOSH (National Institute for Occupational Safety and Health). N95 is not a specific product name. As long as it meets the N95 standard and passes the NIOSH review, it can be called a N95 mask, which can filter particles with an aerodynamic diameter of 0.24 ± 0.6 μm (physical diameter 0.075 μm ± 0.020 μm). More than 95%.

Official Guidelines for Wearing Scientific Masks

Chinese name N95 type mask Foreign name N95 face-mask certification agency NIOSH Class protective masks Classification Cup cover type, folding function The filtration efficiency of aerodynamic diameter 0.075µm ± 0.020µm particles can reach 95% or more

Introduction of N95 mask

The N95 mask is one of nine particulate protective masks certified by NIOSH. "N" means not resistant to oil. "95" indicates that the particle concentration in the mask is more than 95% lower than that of the particles outside the mask when exposed to the specified number of special test particles. The 95% value is not the average value, but the minimum value. N95 is not a specific product name, as long as it meets the N95 standard and passes the NIOSH review, it can be called "N95 mask". The protection level is N95, which means that under the detection conditions specified by the NIOSH standard, the filtering efficiency of the mask filter material for non-oily particulate matter (such as dust, acid mist, paint mist, microorganisms, etc.) reaches 95%.

Function and use

The N95 mask has a filtration efficiency of more than 95% for particles with an aerodynamic diameter of 0.075µm ± 0.02µm. The aerodynamic diameter of air bacteria and fungal spores mainly varies between 0.7-10µm, and it is also within the protective range of N95 masks. Therefore, N95 masks can be used for respiratory protection of certain particulates, such as dust generated during grinding, cleaning and processing of minerals, flour and certain other materials. It is also suitable for liquid or non-oily non-production caused by spraying. Hazardous volatile gas particles. Can effectively filter and purify the inhaled abnormal odors (except toxic gases), help reduce the exposure level of certain inhalable microbial particulates (such as mold, anthrax, tuberculosis, etc.), but cannot eliminate contact infection, illness or death risks of.

The US Department of Labor has recommended that medical personnel use N95 masks to prevent microbial airborne diseases such as influenza and tuberculosis.

Common species

According to the shape of the mask, it is often divided into two types: cup cover type and folding type.

N95 mask

safety standard
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" means not resistant to oil, suitable for non-oily particles.
"R" means resistant to oil, suitable for oily or non-oily particles. If used for the protection of oily particles, the use time should not exceed 8 hours.
"P" means oil proof, suitable for oily or non-oily particles. If used for oily particles, the usage 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 that the filtration efficiency is above 95%, "99" means that the filtration efficiency is above 99%, and "100" means that the filtration efficiency is above 99.7%.

Fitness test

In addition to the filtering efficiency of the N95 mask, the closeness of the mask to the face is one of the important factors determining the effectiveness of the mask. Different types of masks have large differences in their suitability to the human face. Therefore, before using a mask, the suitability of the mask should be checked first. During the tightness test of the wearer's face, ensure that air can pass in and out through the mask when it is close to the edge of the face.

Dust and Medical

Cao Xuejun, deputy director of the Consumer Goods Industry Department of the Ministry of Industry and Information Technology, said at a press conference on the 2nd,
N95 masks refer to masks with a filtration efficiency of 95%. They are divided into industrial dust-proof and medical types. Medical N95 masks have higher protection. [2]

"Approaching the N95 mask production line" reported: "Workers are packing medical protective N95 masks (photo taken on February 8). For the past few days, the only medical protective N95 mask manufacturer in Liaoning Province-Shenyang Shengshi Medical Technology Co., Ltd Continuous production for more than 20 hours a day, to ensure daily production capacity of more than 20,000 masks, to supply the epidemic prevention line in Hubei Province and the epidemic prevention line in Liaoning Province. "[3]

Industrial dust-proof N95 and KN95 are both anti-oil particles, while medical N95 is a medical protective mask (not only anti-particles, but also anti-body fluid, etc.). (The picture of Xinhuanet in the appendix is "Medical Protective Mask" written under the word "N95").
Precautions for use

Wash your hands before wearing a mask, or avoid touching your face with the inside of the mask during wearing the mask to reduce the possibility of the mask being contaminated.

Distinguish the inside and outside of the mask, and up and down.

Do not squeeze the mask with your hands. The N95 mask can only isolate the virus on the surface of the mask. If you squeeze the mask with your hands, the virus will wet the mask with the droplets, which will easily cause virus infection.

Try to make the mask fit tightly to the face. The simple test method is: after putting on the mask, exhale hard, and air cannot leak out from the edge of the mask.

The protective mask must be close to the user's face. The user must shave his beard to ensure that the mask can fit on the face. The beard and anything placed between the mask seal and the face will cause the mask to leak.

After adjusting the position of the mask according to your face shape, apply forefingers with both hands to press the nose clip along the upper edge of the mask to make it close to the face.
Masks should be replaced in time when:
When the respiratory impedance increases significantly;
When the mask is damaged or damaged;
When the mask cannot be tightly attached to the face;
Masks are contaminated (for example, when stained with foreign matter such as blood or droplets);
Masks have been contaminated (have been used in individual wards or patient contacts);
If it is a mask containing activated carbon, and there is an odor in the mask;

Masks have been used longer than recommended.

Performance limitations

Respiratory diseases are not only transmitted through the respiratory tract;
Preventive measures should precede exposure;
The tight structure and efficient filtering of the mask will increase breathing resistance and reduce comfort;
If the mask design is not suitable for the user's face shape, it will affect the suitability and will cause leakage;
Under the requirements of suitability and correct use, protective masks can effectively reduce the concentration of harmful substances by 90%;

The government has not established safe exposure limits for pathogenic microorganisms, and respiratory protection can only reduce the risk of disease, but it cannot eliminate the risk.

Choice of masks

Choose the right mask

Medical protective masks should be the first choice for medical workers, and ordinary degreasing gauze masks should be the first choice for ordinary citizens to use in their daily lives. In special occasions, such as visiting doctors and visiting patients, it is better for ordinary citizens to choose medical masks.

Choose a qualified mask

When choosing a mask, you need to see whether there is a trade name on the package, whether there is information about the manufacturer or supplier, whether there is a mask certificate or instructions for use. Disposable masks must also have a one-time identification, and reusable medical protective masks must also indicate the method of sterilization. In general, ordinary gauze masks must be marked as normal or disinfected. The materials used for masks should be free of odors and harmless to the human body, especially those in contact with the human face. They should be non-irritating and allergic.

Don't forget to check the appearance when choosing a mask

This is a problem that we tend to ignore when choosing a mask. First of all, we must check whether the packaging of the mask is complete and whether it is damaged. There must be no holes or stains on the surface of the mask. Medical protective masks should not have exhalation valves. For close-fitting arch masks, the lateral diameter is not less than 14cm, and the longitudinal diameter is not less than 14cm. The length of the medical protective rectangular mask is not less than 17cm, and the width is not less than 17cm. The number should not be less than 12 layers. In addition, we must remind everyone that if you choose a medical mask, remember to have a nose clip. The nose clip is made of bendable plastic material and the length is not less than 8.5cm.

Expert advice

The hot-selling N95 masks on the Internet can reach 95% after testing and filtering. However, for N95 masks, doctors remind citizens to pay attention: "In theory, the more tightly the mask's protective material is, the better the effect of blocking particulate matter. On the other hand, the closer the mask is, the harder it is to breathe, especially for patients with cardiovascular disease Poor wearing can also cause dizziness and difficulty breathing due to lack of oxygen, so choose more carefully. "