Use LED lamps for disinfection and sterilization
The popularity of COVID-19 has raised public awareness of UV disinfection, which is also reflected in the increasing number of LED-based products on the market.
Ultraviolet light can be used to disinfect the surface of air, water and various objects. According to the International Ultraviolet Association (IUVA), it can help reduce the risk of spreading the COVID-19 virus.
UV is divided into several ranges (Figure 1). UV-A or black light ranging from 315 to 400nm, used in applications such as light stability testing, curing, phototherapy, insect repellent and tanning beds, long-term exposure to UV-A can cause skin tanning and premature Ageing.
UV-B with a wavelength range of 280~315nm is dangerous. Because prolonged exposure to UV-B is associated with skin cancer, skin aging, and cataracts, commercial applications include curing and phototherapy in medicine.
200-280nm wavelength range is UV-C. This ultraviolet band has nothing to do with skin cancer because photons do not penetrate deeply into the skin, but according to IUVA research, exposure to UV-C can cause skin discomfort like severe burns and damage the retina of the eye. UV-C photons can also interact with RNA and DNA molecules in microorganisms, thereby effectively destroying them. Mercury vapor lamps that emit UV-C have been used for disinfection for decades, but, like other forms of lighting, have transitioned to products that use LED light sources.
Health experts believe that the main mode of transmission of COVID-19 is through contact with airway or respiratory droplets on the surface of objects. The currently available LED-based sterilization and disinfection products are mainly used for surface disinfection. With the expansion of these equipment markets, it is most likely that more advanced air disinfection systems will be introduced. The available products have the advantages of being suitable for other types of LED lighting: small size, easy integration with other devices such as occupancy sensors, and low power consumption requirements. But these products are often more expensive, and the range of surface area that can be processed in real time will be more limited.
The initial focus of the switch to using LEDs is that the life of LEDs is significantly shorter than existing mercury vapor lamps. However, this concern is based on the evaluation of continuous operation in traditional applications such as sealed purification systems and does not take into account that (sometimes necessary) intermittent use of sterilization products is possible. Like all LEDs, UV-C LEDs can be cycled almost indefinitely without adversely affecting the light output; in addition, mercury vapor lamps require a few minutes of warm-up time to reach maximum light output, and LED products can reach full output almost instantly Level. In addition, unlike mercury vapor lamps, LED-based products can only provide the wavelengths needed for optimal results without wasting energy in the form of ineffective wavelengths.
Generally speaking, another problem of sterilization lighting products is the verification of product safety and performance requirements. According to Carl Bloomfield, global director of commercial infrastructure for Intertek’s electrical business, their product evaluations focused on brightness parameters, sterilization declaration verification, safety compliance, and applicable EMC. Standards development agencies have begun work on testing standards, but standards do not yet exist, so Intertek relies on its industry and technical expertise to design evaluation protocols for specific products and their intended applications. Safety compliance can be particularly complex because depending on the product and its intended use, it includes fire, electric shock, mechanical risks, optical hazards, ultraviolet output, and ozone emissions.
In addition to products that use ultraviolet light for disinfection, there is a relatively new product series called "Visible Light Disinfection (VLD)". The indigo (blue-violet) wavelengths emitted by the LEDs used in these products are safe for the human body to be exposed to for a long time, so that they can continue to eliminate bacteria sensitive to these wavelengths.
VLD products are usually installed in a space as part of the realization of permanent lighting, sometimes combined with white light sources for general lighting. It is worth noting that VLD disinfection is not effective for all bacteria and is completely ineffective against viruses.
According to Research and Markets research, the market for ultraviolet disinfection equipment is expected to grow at a compound annual growth rate of more than 12% in the next five years. LED-based products are expected to play an important role in driving market growth due to their long service life and high energy efficiency.