UV advantages: 1) disinfection and sterilization; 2) promote bone development; 3) it is good for blood color; 4) it can occasionally treat some skin diseases; 5) it can promote mineral metabolism and vitamin D formation in the body.
Ultraviolet disadvantages: 1) cause skin aging to produce wrinkles; 2) produce spots; 3) cause dermatitis; 4) cause skin cancer.

Sterilization principle of UVC.
Among all the wavelengths of ultraviolet, only short-wave ultraviolet UVC has the effect of sterilization and disinfection, which is a pure physical disinfection method. It has the characteristics of broad-spectrum, high efficiency, fast and thorough, no need to add chemicals, no drug resistance, no secondary pollution and so on.
UVD ultraviolet of wavelength 185nm can change oxygen O2 in air into ozone O3.Ozone has strong oxidation effect and can effectively kill bacteria, but wavelength 185nm ultraviolet does not have germicidal effect. The dispersion of ozone can just make up for the shortcomings that ultraviolet rays can only spread in a straight line and disinfection has a dead angle. it can reach any corner of the space with the air, making sterilization and disinfection more thorough.
The principle of ultraviolet sterilization: through ultraviolet irradiation on bacteria, viruses and other microorganisms, it destroys the molecular structure of DNA (deoxyribonucleic acid) or RNA (ribonucleic acid) in microbial cells, causing DNA chain breakage, nucleic acid and protein cross-linking rupture, resulting in growth cell death and regenerative cell death, achieving the effect of sterilization and disinfection. Among them, the ultraviolet disinfection effect of wavelength 253.7nm is the best.
Ozone sterilization principle: UVD ultraviolet radiation of wavelength 185nm irradiates the air, which can decompose the oxygen O 2 molecules in the air, and the resulting O atoms combine with O 2 molecules to produce ozone O 3. Ozone O3 has strong oxidation, which can destroy the cell wall of decomposing bacteria, and penetrate into the cells to oxidize and decompose glucose oxidase, ribonucleic acid (RNA), deoxyribonucleic acid (DNA), proteins, lipids, polysaccharides, macromolecular polymers, and destroy the metabolism and reproduction of bacteria, thus achieving the effect of sterilization and disinfection.

Germicidal characteristics of UVC.

High-efficiency sterilization: the germicidal effect of ultraviolet rays on bacteria and viruses is generally completed in a few seconds, which occurs almost instantly, and the germicidal disinfection ability is 600 to 3000 times larger than that of chlorine.
Broad-spectrum sterilization: ultraviolet technology in all the current disinfection technology, the broad-spectrum sterilization is the highest. It can kill almost all bacteria and viruses with high efficiency.
Sterilization is more thorough: ultraviolet radiation combined with ozone (UVC+O3) can exert more powerful and thorough disinfection power. Ultraviolet rays irradiate the air and the surface of objects in a straight line to achieve strong sterilization and disinfection; ozone permeates into every corner of the room with the air, killing indoor bacteria thoroughly.
Completely environmentally friendly: ultraviolet light emits ultraviolet radiation for sterilization and disinfection, ultraviolet rays irradiate oxygen in the air to produce ozone, ozone is strongly oxidized to kill bacteria and viruses, and there is no need to add any chemicals in the whole sterilization process to achieve complete environmental protection.
There is no drug resistance: ultraviolet or ozone directly destroy the DNA, RNA and protein in bacterial virus cells, resulting in direct cell death and inability to reproduce and replicate, and there is no drug resistance. On the other hand, the sterilization of other chemicals will make bacteria and viruses resistant to drugs, resulting in the failure of the sterilization effect of the chemical.
No secondary pollution: ultraviolet and ozone cause bacteria and viruses to die directly, without any other chemical pollutants; at the same time, ozone is converted into oxygen in 15 minutes (ozone half-life) at room temperature without any residual secondary pollution.

Germicidal efficiency of UVC.
Germicidal efficacy of UVC ultraviolet against common bacteria and viruses (radiation intensity: 30000μW / cm2).

Prevent the harm of UVC ultraviolet rays to the human body.
The main parts of UVC UV damage to the human body are eyes and exposed skin. Short-term high-intensity irradiation can burn eyes and skin, and long-term high-intensity irradiation can even cause skin cancer.
UVC UV penetration is very weak, ordinary transparent glass, clothing, plastic, dust and so on can completely block. Therefore, wearing glasses (avoid looking directly at the UV light without glasses) and covering the exposed skin as much as possible can protect your eyes and skin from UVC UV damage.
Exposure to ultraviolet rays for a short time is like being exposed to the hot sun, which is not harmful but beneficial to the human body. UVB ultraviolet rays can promote the metabolism of minerals and the formation of vitamin D in the body.
Principles to prevent UVC UV damage: 1) wear glasses (ordinary glass or resin lenses); 2) avoid looking directly at UV lights; 3) wear long-sleeved clothes to cover bare skin such as hands; 4) use objects around you to block UV rays, such as walls, furniture, curtains, books and newspapers; 5) avoid exposure to UV for a long time, short-time exposure does no harm to the human body.