PPE

PM2.5 mask in name but not in reality

With the gradual normalization of haze weather in China, a variety of masks boasting the protective effect on PM2.5 have appeared one after another, becoming the main “weapon” in people’s daily life to fight against haze. However, some experts said that most of the “PM2.5 masks” sold on the market belong to the concept of speculation, and the gimmick is greater than the actual effect

you can buy it everywhere

according to the reporter’s investigation, the current price of anti haze masks ranges from one or two yuan to thirty or forty yuan, and the materials also include cotton yarn, activated carbon and other materials

recently, the reporter visited a small commodity market in Chaoyang District of Beijing and found that a variety of masks claiming to be “anti PM2.5” are on sale. Outside a booth selling hats and scarves, there are many colorful cartoon masks in a row. The price is 12 yuan each. Beside the masks, there is a sign that says: fashionable and beautiful masks, PM2.5 prevention

the reporter spent 10 yuan to buy a colorful lattice mask. After taking it apart, he found that the mask was made of three layers of cotton cloth, and the edge of the mask was off-line. This kind of mask, not to mention the protective effect, can not even guarantee basic health. However, it is such masks that students and white-collar workers buy from time to time” Medical masks work well, but they are often not liked by young people. ” Experts say so

in pharmacies, the sales of protective masks doubled. According to a pharmacist in a drugstore, “recently, medical or disposable masks sell better than before. We also recommend that some patients who are allergic to cold air and poor air go out to wear professional masks, especially those with respiratory diseases such as rhinitis and asthma, as well as special groups such as the elderly, children and pregnant women.”

PM2.5 masks are also popular on the 1nternet. The reporter logged on to a number of shopping websites and found that the “PM2.5” labels made by sellers to sell masks are overwhelming, and there are a variety of styles and models. But whether it’s anti particulate matter, anti formaldehyde, anti odor or activated carbon, sellers all boast that the masks they sell have the special function of “anti haze”

the reporter entered the keyword “PM2.5 mask” on Taobao, and searched 30900 products in minutes, including medical masks, industrial masks and masks with filter layer, among which activated carbon chip and N95 masks for medical use are the most common. 1n addition, some masks that claim to have self-developed ultrafiltration technology are also favored by many consumers

the anti PM2.5 effect of activated carbon is not targeted

whether the anti haze mask is effective or not is a big doubt on the minds of consumers” 1 feel that the effect is very limited. 1 can smell all kinds of car exhaust. 1 can only say that it’s a little better than a few yuan in general. ” Ms. Li, the consumer, spent 35 yuan on a mask two months ago, but felt that the effect was very general

it seems that it is difficult to get a convincing result from various experiments on the 1nternet. For example, two widely circulated experiments have come to two opposite conclusions: one is that activated carbon is the best, and the other is that activated carbon masks are totally unreliable. This makes the already dazzled consumers fall into the puzzle of the constant management of scissors

in Taobao, a “personalized activated carbon mask” with a price of 25.8 yuan sold the most, with a total of 109034 pieces sold, and 99041 pieces sold in the last month alone

in the introduction of the mask product, an experimental report of “anti haze: wearing activated carbon mask works best” was quoted, and the test report of British its laboratory and other materials were displayed, calling its product “good filtering effect”

another popular brand “thickened warm autumn and winter anti PM2.5 dust and antibacterial mask” is tit for tat. 1t also quotes the experimental results of an article “activated carbon mask intercepting PM2.5 is not reliable” to help itself. The mask product said in the introduction that the ultra filtration technology adopted by the mask was independently developed by the company and “has passed the authoritative testing by the American Nielsen organization” and “can effectively filter PM2.5 air particles”

the reporter found in the standard of ordinary skim gauze mask that to detect whether different parameters are up to the standard, it is necessary to use the specified measuring tools and test methods, and there are requirements for temperature and humidity in the specific operation. 1t’s not like the popular experiment that we can get a convincing answer with a simple instrument< According to Wang Yan, Professor of School of environmental science and engineering, Shandong University, "activated carbon masks may have certain effects, but it is not targeted to use activated carbon to prevent PM2.5." Wang Yan introduced that activated carbon does have adsorption effect, but mainly for odorous gas, and PM2.5 is a particle however, there are not only particles but also harmful gases such as hydrogen sulfide in the haze. Activated carbon can indeed absorb some gases, but once it is saturated, it can not continue to absorb, and it can not completely rely on activated carbon to resist PM2.5 the effect of most masks is limited the reporter found that for medical masks, there are mandatory national standards issued by the State Food and drug administration, which are: technical requirements for medical protective masks (GB19083-2003) and ordinary skim gauze masks (gb19084-2003). The standard has strict and detailed requirements for the size, layer number, gauze density and even outer packaging of the mask in the hospital environment, the material room of Beijing 1nstitute of medical device inspection conducted the airtight test on several kinds of masks. The results showed that the ordinary gauze masks did not block the PM5 level; Medical surgical mask and disposable medical mask can block particles larger than 4 μ m in diameter. For particles of 0.3 μ m, the transmittance of medical surgical mask is 18.3%, and that of ordinary disposable medical mask is 85.6%. This shows that the blocking effect of the two kinds of medical masks on fine particles is limited for another popular choice “N95 mask”, relevant experts do not highly recommend it. First, it is not easy to buy regular products. Second, N95 masks are not suitable for all people. 1t is understood that N95 masks are only worn by medical staff during the period of avian influenza and SARS. 1t is difficult to breathe when wearing such masks, which is not suitable for the elderly, children and pregnant women< There is no relevant national standard yet. Zhao Danqing, an expert of China antibacterial Association, once said publicly that PM2.5 is equivalent to one twentieth of the size of a needle tip, and ordinary non-woven mask fiber can not block it at all at present, there is no relevant national standard for PM2.5 masks in China, and 3M, Honeywell, Gangkai and other masks clearly indicate that they comply with the gb2626-2006 national standard. This standard is called “respiratory protective equipment self-priming filter type anti particulate matter respirator”, which is only applicable to the filtration of non oily particulate matter and can reach 90% or 95% of the filtration standard, but does not specify the particle diameter as the developer of “N95 mask”, Zhang Linghan, President of 3M Greater China, admitted in an interview with the media that “PM2.5 mask” is not a scientific concept, and “N95 mask” can not be called “PM2.5 mask”. 1t is understood that “N95” is the standard of the National 1nstitute of occupational safety and health of the United States, which is the lowest in all levels of filtration efficiency of anti particulate matter respirators. 1ts filtration efficiency for non oily particles, such as dust, paint mist, acid mist and viruses, can indeed reach more than 95%. Although it can filter PM2.5 with particle size less than 2.5 microns, it is not specially designed for this single function, “3M will not call it PM2.5 mask” experiments show that N95, n99 and other medical masks are indeed effective in preventing respiratory infectious diseases, while the general cotton gauze masks only have dust-proof effect it is very important to keep the mask clean the effect of activated carbon is difficult to determine, N95 mask is not suitable for ordinary people to wear for a long time… Under the premise that the country has not issued a unified standard for anti haze masks, experts say that the key to choose masks lies in the pore diameter and density of mask fabric. At the same time, it is particularly important to keep the mask clean experts suggest that if the air quality is good, you can wear ordinary cotton masks; 1n haze days, medical disposable masks and 18 layer gauze masks can be selected. 1f the air pollution index is particularly high, people who have been engaged in outdoor work for a long time can consider N95 masks, but it is not recommended to use them for a long time and in a large range not only that, many people pay too much attention to whether the mask can prevent PM2.5, but ignore the hygiene of the mask itself. Some people take off the mask and put it into their pocket, but they don’t know that there are more bacteria per unit area in the pocket than in the air in addition to daily protection, pay attention to whether the mask can prevent haze, but also pay attention to the mask material. For example, young people like cartoon masks, experts do not recommend wearing. Because many of these masks are made of chemical fiber and have bright colors, the dye itself may be substandard when choosing a mask, you should pay special attention to the fit between the mask and the face. 1f there is no fit around the mask and there is a gap, you can go in like haze. At the same time, we should also try to buy masks from formal occasions, and pay attention to the qualified marks copyright notice: This article is reproduced from the network media, only represents the author’s point of view, and has nothing to do with this website. 1f the information column articles and comments violate your legal rights, please call to let us know and we will deal with them in time

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