Because of the Wuhan pneumonia, almost everyone in the country is now scrambling for masks. Here is a quote:Happy little pharmacist“The masterpiece is published here with permission. In addition to the following specifications, the little pharmacist also reminds that masks are not just available for purchase now. There are a few points to note: 1. It needs to have an approved font size 2. It needs CNS font size 14774 3. The material needs to be PP non-woven fabric and waterproof. When buying a mask, pay attention to the words “medical use”. There are also masks for general warmth, decoration, pollen prevention… for different purposes. When using them, the colored side should face outward and cover the nose completely. The metal strip above should be pressed according to the shape of the nose and replaced every four hours. It is not necessary to wear a mask all the time in an open outdoor space, but it is necessary to wear a mask when entering a crowded indoor environment.
Recently, many people have begun to pay attention to the specifications on masks, so I will briefly write down the common labels BFE, PFE, and VFE.
BFE
BFE is Bacterial Filtration Efficiency (Bacterial Filtration Efficiency), which measures the efficiency of the mask in filtering bacteria.
PFE
PFE is the particle filtration effect (Particulate Filtration Efficiency), which measures the efficiency of the mask in filtering particles.
VFE
VFE stands for Viral Filtration Efficiency, which measures the efficiency of a mask in filtering viruses.
BFE is measured as the mask’s ability to filter microbial particles from within. This test is mostly conducted with particles around 3.0 μm (microns) and a flow rate of 28.3 lpm (liters per minute).
The so-called “N95” means dust masks that have passed the US NIOSH N95 certification.
The filtration effect for non-oily suspended particles of 0.3 μm (microns) reaches 95%.
In addition to referring to the specifications of American industrial dust masks,
You can also refer to similar regulations and standards of the European Union, Japan, etc. as a reference for purchasing masks.
EU product classifications are FFP1, FFP2, FFP3,
Australian classifications are P 1, P 2, P 3
Japanese classifications are DS 1, DS 2, DS 3, etc.
Its standards are similar to those of the United States. Therefore, when choosing these levels of dust masks, you can achieve similar effectiveness as N95 masks.
Some biotechnology companies have developed a method of weaving bioceramic powder onto cotton cloth to make masks.
Since the powder has reached the nanometer level, it can effectively block bacterial invasion.
You may ask whether a three-layer non-woven mask with 99% PFE is more effective than N95 (that is, 95% PFE)?
In fact, this is not the case. According to the NIOSH N95 standard, the test will be conducted at a flow rate of 0.3 μm and 85 lpm. If a surgical mask with a PFE of more than 95% is used for the NIOSH N95 test, the result is often lower than 70%.
The main reason is that the efficiency of the filter material is often affected by the amount of air circulation. The greater the air circulation, the lower the efficiency of filtering particles.
The main function of a surgical mask is to prevent the user’s droplets from being transmitted to others. However, the outer layer of PP water-repellent material can also block other people’s droplets from being transmitted to the user’s mouth and nose.
In addition to the quality of the mask, the most important thing is whether it has a good fit with the face after putting it on, and whether the front of the mask is facing outward to achieve the best protective effect.
Some people may say, should I use P95?
Let’s put it this way, the U.S. National Institute for Occupational Safety and Health has three levels of N, R, and P for facial protective equipment.
N level stands for Not Resistant to Oil, which means that the filter material cannot be used in an environment containing oil and gas; R level stands for Resistant to Oil, which means that the filter material has the ability to isolate oil and gas within 8 hours; P level stands for Oil Proof, which means that it can completely isolate oil and gas.
The filtration efficiency of each level can be divided into three levels: 95, 98 and 100. N-95 means that more than 95% of particles can be captured at any time during the test, and N-98 can capture 98% of particles.
N-100 can capture 98.97% of particles, and so on for other levels.
In addition, biological particles are general particles rather than oily particles, and there is no need to use R-level or P-level filtration for oily particles.
There are currently a lot of mask teaching options circulating on the Internet. In fact, it is easy to cause misunderstandings just by judging from the appearance or name. For example, the most misunderstood one is activated carbon.
In fact, as long as the activated carbon is filtered and waterproof, it will still be effective.
(Thanks to Sanxia Peking University Pharmacy for providing the photo)
Therefore, when purchasing, it is better to look at its font size and composition. This is the more correct way.
You can check the information here:
Western medicine, medical equipment, and special purpose cosmetics license inquiry
Comprehensive comparison of medical mask testing standards in various countries
Grades of particulate respiratory protective equipment
In addition, 7-11, FamilyMart and other supermarkets now have medical masks allocated by the government for purchase. Each person can buy one pack at a time (three, you can buy them every day). There is no shortage of masks in the country. There is no need to panic and hoard. Do good daily health care, wash your hands frequently, wear a mask when going out, and stay in crowded confined spaces less. I wish everyone good health and safety.
Source: KOCPC Chinese