Which masks can prevent viruses?

The standard GB/T 18830, which is implemented by reference, evaluates the anti-ultraviolet performance of textiles, and requires some basic physical and chemical properties of fabrics, but does not assess the virus protection effect, filtration efficiency and other indicators. Therefore, from the design principle of its materials, this kind of mask does not have anti-virus or medical protection function.

Which masks can prevent viruses?

The "Guidelines for Wearing Masks for the Public and Key Occupational Groups (202 1 Edition)" issued by the Bureau of Disease Control and Prevention of the National Health and Wellness Committee clearly points out that at this stage, the public is advised to choose disposable medical masks, medical surgical masks or masks with protection levels above. Details are as follows:

Medical surgical mask

Mainly composed of three layers of materials, the core layer is composed of meltblown cloth, which has a good function of filtering fine particles and viruses. The medical surgical mask has good sealing performance, which can prevent body fluid pollution and novel coronavirus infection, so it can be used for the general population to prevent novel coronavirus infection.

N95(KN95) mask

The protective function of N95 mask is better than that of medical surgical mask, but the price is higher and the wearing comfort is slightly lower. It is mainly used for front-line doctors in fever clinics and patients in COVID-19.

According to the latest announcement of Beijing CDC, it is also recommended to wear N95 or KN95 masks in the following special scenes if physical conditions permit:

When seeking medical treatment, accompanying medical treatment or taking medicine in a medical institution;

When visiting the elderly, babies or people with basic diseases;

When conducting nucleic acid detection and receiving express delivery;

When entering or leaving closed places with dense people and poor ventilation, such as KTV, underground farmers' market, underground chess room, etc.

It is difficult to determine the risk, but it is necessary to communicate with strangers at close range, such as door-to-door service of maintenance or decoration personnel and communication with sales staff. Which masks can't prevent viruses?

"Antibacterial and antiviral" non-medical mask

At present, there are non-medical masks on the market that claim to be "antibacterial and antiviral". Generally, all kinds of antibacterial agents are added by mixed spraying. The main additives are nano titanium dioxide, nano silver, quaternary ammonium salt, copper ion/copper oxide, traditional Chinese medicine extract and so on. The safety and effectiveness of such products should be fully studied and verified.

In terms of safety, the risk of long-term inhalation of normal people caused by the shedding of antibacterial agents on masks should be evaluated; In terms of effectiveness, whether the addition of antibacterial agents affects the filtering effect of masks and the antibacterial and antiviral effects of antibacterial agents need to be verified. Under the premise that the clinical effectiveness of this kind of mask products has not been fully verified, adding antibacterial drugs will introduce new risks. At present, in the pre-marketing evaluation of medical devices, the risk-benefit ratio of continuous long-term use of such products is insufficient and has no significant clinical significance.