Principle and advantages of deep UV LED sterilization

Novel coronavirus raging in 2020 the imprint is engraved on my heart. As of March 1st, novel coronavirus pneumonia (COVID-19) infection has been diagnosed by more than 80000 people and more than 2900 deaths. The new epidemic situation makes "disinfection" a high-frequency word. 75% alcohol, 84 disinfectant, hand sanitizer and other disinfection methods are mentioned time and again.

A novel coronavirus infection pneumonia diagnosis plan (trial version fifth) released by the National Health Protection Committee mentioned "viruses are sensitive to ultraviolet and heat", and ultraviolet disinfection and sterilization has become a hot topic. In the past, ultraviolet disinfection was only used as a disinfection method for special scenes such as hospitals, and the vast number of consumers were still unfamiliar with ultraviolet disinfection.

So how does ultraviolet kill bacteria and viruses? What are the characteristics of ultraviolet sterilization? What are the precautions? Why is deep UV LED called the artifact of sterilization?

1、 The principle of ultraviolet sterilization

Recently, many articles on UV sterilization have been popularized

First, UV can be divided into UVA long wave ultraviolet (wavelength range 315 – 400 nm), UVB medium wave ultraviolet (wavelength range 280 – 315 nm), UVC short wave ultraviolet (wavelength range 200 – 280 nm) and VUV vacuum ultraviolet (wavelength range 10 – 200 nm). UVA long wave ultraviolet is often called near ultraviolet, UVC short wave ultraviolet is often called deep ultraviolet.

Second, UV is a kind of mutagen. In a specific wavelength range (mainly UVC) and high enough dose, UV can cause abnormal chemical bonds between DNA or RNA adjacent pyrimidine molecules in bacteria and viruses and other microbial cells, hinder the replication of DNA or RNA, resulting in microbial cell death. Deep UV LED can achieve the effect of sterilization and disinfection by emitting UVC wavelength of deep UV.

Third, during the SARS period, researchers from the Chinese Center for Disease Control and Prevention found that the SARS virus could be killed by irradiating the coronavirus for 60 minutes with a deep ultraviolet radiation intensity of more than 90 UW / cm2. The novel coronavirus novel coronavirus is similar to the SARS virus and belongs to the single strand positive strand RNA virus. Therefore, theoretically and reasonably using ultraviolet rays can effectively kill the new coronavirus.

3、 Advantages of UV LED

At present, there are mainly two kinds of UV light sources for sterilization: traditional mercury lamp and deep UV LED. Compared with the disadvantages of traditional mercury lamp, deep UV LED has obvious advantages in policy and technology.

Disadvantages of traditional mercury lamp:

(1) It is bulky in shape, large in size and equipped with high voltage electricity.

(2) It takes a long time to start and can't be used immediately.

(3) Fragile, short service life, up to 90% of the service life consumed in the frequent switching stage.

(4) It is highly toxic and will cause mercury leakage after rupture, polluting the environment and seriously endangering human health.

Policy advantages of deep UV LED: the United Nations Minamata convention signed by 128 countries in the world has officially entered into force in China in August 2017. The treaty clearly states that all countries will ban the production, import and export of all kinds of mercury containing products from 2020, and the production and sales of traditional mercury lamps will be banned. The Chinese government has issued a series of policy documents such as the list of toxic chemicals strictly restricted in China and the list of priority controlled chemicals (the first batch), which put forward clear requirements for mercury control. As a big country of traditional mercury processing and manufacturing and mercury pollution, the Chinese government actively implements the requirements of Minamata convention. Although UV mercury lamp used for curing and sterilization is not included in the main regulation this year, in the long run, just as it is an inevitable trend for led to replace traditional light source in the field of general lighting, deep UV LED, as a green and environmental protection new UV solid-state light source, will be the only alternative to traditional UV source mercury lamp. With the entry into force of Minamata Convention and the continuous progress of deep UV LED technology, deep UV LED will usher in the rapid growth of its industrial scale.

Technical advantages of deep UV LED: in various sterilization methods, only deep UV LED has the advantages of energy saving, instant use, space saving, maintenance free, non-toxic and harmless, long service life, no pungent smell, etc. Compared with other sterilization methods, deep UV LED has obvious technical advantages.