The North has been attacked by "haze" again. No one knows PM2.5 anymore, and its harm doesn't need to be mentioned. In winter, a variety of anti haze masks emerge in endlessly. Is it really useful? There are many masks on the market, among which the most common ones are cotton masks, medical surgical masks, activated carbon adsorption masks, N95 masks, etc. However, only N95 mask can really block particles under 2.5 microns.
Can anti haze mask really have the effect of anti haze?
The phenomenon of haze is becoming more and more serious in China, and the anti haze mask has also become a necessary product for citizens. However, experts from respiratory department of Beijing Tongren Hospital said that at present, most of the masks that claim to be able to filter PM2.5 are conceptual products, just gimmicks, which have no blocking effect on PM2.5 at all. The mask that can filter PM2.5 generally has 7 layers, such as N95 mask of operating room level. But this kind of mask has poor air permeability, and the elderly with poor cardiopulmonary function will be at risk if they wear it.
Recently, Beijing Administration for Industry and Commerce found that many brands of masks were suspected of false publicity of haze prevention during law enforcement. At present, the production standard of dust masks is the industrial standard that must be achieved under dust environment. The highest protection ability for PM2.5 level air particles is 95%. The propaganda terms such as "reassuring 100%" filtering effect 99% "on masks exaggerate the actual function of masks Effectiveness. This shows that the anti haze function of most masks is grandstanding.
There are several types of masks
Cotton mask: cotton mask with enough layers can filter a considerable part of dust and bacteria. The principle of this kind of fiber mask is a mechanical barrier, through which large particles can be blocked.
Medical surgical mask: the disposable mask used by surgeons is made of non-woven fabric, which is divided into three layers. The outer layer has anti foam design, middle layer filtration and inner layer moisture absorption. This mask is mainly used to protect doctors from droplets and splashes. It is mainly used for antibacterial.
Active carbon mask: add a thin layer of active carbon or other materials for adsorbing gas on the particle protective mask, which can reduce some gases with low concentration and unpleasant smell, that is to say, reduce peculiar smell. In terms of the performance of particle protection, there is no difference with or without carbon. The active carbon mask that can reduce the odor does not increase the protection of particles.
Anti particle respirator: special filter materials are used, and the main protection objects are particles, including dust, haze, smoke and microorganism.
Expert suggestion: it is best to choose the type of mask according to the exposure time and senior situation in the polluted environment. If the outdoor travel time is very short, you can choose a good filter mask to achieve the best effect. If you are outdoors for a long time, you should choose a respirator with both air permeability and filtration according to your physical condition.
Be sure to buy the particle respirator correctly!
3M particle protective mask is commonly known as 3M dust mask. The use of protective masks to protect the health of workers at work belongs to the category of occupational health. The anti particle respirator is used to reduce all kinds of harmful particles suspended in the air inhaled through the respiratory tract (from coarse sand dust and dust, to fine dust, smoke and dust produced in various production processes, air pollutant PM2.5, including fine pathogens).
There are different filtration efficiency levels from low to high, which are respectively regulated by the applicable standards of the products. For example, China national standard gb2626-2006 stipulates three filtration efficiency levels (90%, 95%, 99.97%). 3M anti particle respirator is widely used for occupational protection. It aims to produce particles in the process of production, such as mineral dust, casting dust, welding smoke, drug dust, wood dust, etc. the government regulates and guides the selection of specific regulations and standards for such application. Generally, 90% filter efficiency level can be used for all kinds of low toxic dust, but it is not recommended for smoke (such as welding The 95% level is applicable to smoke (such as welding smoke), highly toxic dust (such as heavy metal lead, cadmium, and drug dust) and pathogenic microorganism (such as influenza virus), and 99.97% level is applicable to particles with higher toxicity and greater harm, such as radioactive dust, carcinogens, etc.