The year 2020 can be called the year of novel coronavirus (COVID-19), which has swept not only its city of origin, i.e. Wuhan in China but also the entire world. As a result, the world is trying to come to terms with the ‘new normal’ by wearing masks and gloves and by following social distancing, i.e. maintaining a minimum distance of 6 feet from each other. As an aftermath of the coronavirus pandemic, people have become even more conscious about keeping the area in and around their house clean and are disinfecting any object that enters their premises. Thus, in response to the pandemic, governments and companies across the world are taking to several sanitation practices, specifically ultraviolet (UV) light, a disinfectant which has been in use for decades in hospitals and other health care services.
Decoding Ultraviolet light
UV radiation can be divided into UV-A (320 to 400 nm), UV-B (280 to 320 nm) and UV-C rays (200 to 280 nm). The reason why UV radiation is effective as a disinfectant against various bacteria and viruses is it disrupts their DNA and thus prevents them from performing vital functions. Yet, not all kinds of UV light is effective for disinfection. For disinfection purposes, the optimum wavelength required is in the range of 260 nm to 275 nm and germicidal effectiveness falls exponentially with longer wavelengths.
Power intensity, wavelength and exposure duration are some of the major factors typically used to determine effectiveness of UV light against microbes. For example, on surfaces and in water, there might be several germs with differing optimal absorption wavelengths. For any given wavelength of Germicidal UV (GUV), its exposure duration and power would need to be determined in order to achieve the required level of sterilization.
While developing a product for a particular disinfection requirement, it is imperative to gauge the performance of UV LEDs under different conditions and how these conditions are related to one another. While power and wavelength are the first factors a design engineer considers, these are not the only factors to be considered. The wavelength, viewing angle and radiation pattern provide insights with respect to the usefulness of the power specified and current related information provide room for control and design of system for end of life requirements. Lastly, thermal related information such as maximum junction temperature and thermal resistance are important specifications for development of an efficient and application specific thermal management.
GUV is ideal for use in offices, hospitals, parking lots, hotels, factories and warehouses, train stations etc. to make the manual sanitisation process easier and more effective. Many companies in India will be launching a pre-tested UV product line that will include sanitization enclosures, wands, remote-controlled robots etc. applicable for both industrial and residential usage.
Is UV light safe for humans?
UV-C light only penetrates the upper layers of the skin and eye while the shortest wavelengths hard penetrate living cells. Hence, it may cause a slight, transitory sunburn from accidental over-exposure to the skin. Even though GUV lamps may pose a theoretical delayed hazard, incidental UV exposures would not significantly increase one’s lifetime risk for cataract or skin cancer when compared with exposure to UV light from the sun on a daily basis. As a precaution, it is important to avoid entering the disinfected area after 30-40 minutes of operation of a GUV lamp. Also, one should not look directly into the disinfection lamp in order to prevent damage to the eyes. The products developed using this technology will also have to be intelligent keeping in consideration the requirements of daily usage.
UV to experience an accelerated usage
While some of the effects of this pandemic might be short-lived, it is certain that the emphasis on cleanliness will stay. Consumers are likely to remain conscious of hygiene and it is going to influence their purchase decisions such as where to shop, which restaurant to dine in etc. In 2018, the global UV disinfection equipment market was valued at $1.1 billion. According to Allied Market Research, it is expected to reach $3.4 billion by 2026. Slowly, we see an accelerated adoption of technologies like GUV not just in hospitals, health care services and public spaces but also in common households. By investing in disinfection solutions such as GUV, we would be able to ensure better protection of our health and would be able to adjust more easily to the ‘new normal.’
Author:
Parag Bhatnagar,
Senior Vice President
Havels India Ltd.
