UV-C LED Sanitization – An Innovation in Lighting
December 21, 2021
A recent development in LED lighting technology is expected to make a big impact on human quality-of-life. The emerging trend consists of expanding the application of ultraviolet light to sanitize surfaces, air, and water.
What is UV Light?
Ultraviolet light is emitted by the sun and can be categorized into three basic wavelengths: UV-A (315-400 nm), UV-B (280-315 nm), and UV-C (200-280 nm). UV-A radiation passes through Earth’s atmosphere. Exposure can increase risk of eye cataracts in humans and also has an impact on the aging of plastics. UV-B exposure impacts human skin and correlates to suntans, sunburns, and aging effects.
The third UV type, UV-C, is employed in sanitization applications. Humans receive no natural exposure to UV-C from the sun as UV-C is completely filtered out by the Earth’s atmosphere, so no organism on Earth has developed any type of immunity to UV-C. Using LED technology to artificially produce UV-C allows it to be used as an effective sanitizing agent.
How Does UV-C Sanitization Work?
UV-C radiation impairs the DNA/RNA of all small microorganisms. The damage caused by UV-C radiation prevents the bacteria from reproducing itself and viruses are inactivated. Exposure to UV-C radiation kills nearly all strains of bacteria, virus, and fungi. The amount of disinfection depends on the dosage applied. UV-C dosage is dependent upon three factors:
- Radiation wavelength
- Irradiance - the energy applied per unit area
- Exposure time
Different organisms respond in varying degrees to these three dosage factors.
Where Can UV-C Sanitization be Used?
UV-C sanitization can destroy more than 99% of a variety of pathogens including e-Coli, Giardia, Salmonella, and even SARS-CoV-2 (COVID-19). Radiation can be applied to surfaces such as furniture, handrails, sinks, medical instruments, etc.
UV-C light bulbs have been used to purify water in municipal water supply facilities for decades. Now, the newest compact, power-efficient UV-C LED emitters can be applied to water purification in devices such as water filters, faucets, washing machines, or dishwashers.
Finally, UV-C can be integrated into air purification systems to disinfect air-borne bacteria and viruses in public transportation, offices or medical facilities.
UV-C LED Example:
The Oslon UV 3636 is a family of LEDs with a 275 nm wavelength that can eliminate bacteria and viruses. The Oslon UV 3636 comes in 4.7mW, 13.5mW, and 42mW versions – all fit inside a compact footprint of 3.6mm x 3.6mm. The extremely compact dimensions of LEDs make them easy to install, enabling direct interaction with the material being sanitized. Direct integration of the LEDs also protects people from exposure to the high-energy, short-wave UV-C light.
ams OSRAM is also leader in optical sensor technology and has recently demonstrated an alpha-version of a light sensor AS7331 that is capable of simultaneously measuring UV-A, UV-B and UV-C radiation. The pairing of a UV light sensor with a UV emitter makes a lot of sense. As discussed, sanitization success depends on the UV-C dosage factors. Including a UV-C sensor makes it possible to measure the radiant flux energy during the treatment process. Knowing the energy provided enables a host controller to adjust or balance the exposure time as needed.
Two advantages of the optical UV sensor include providing information about when the sanitization process is complete and ensuring that only the required amount of radiation is used. These lead to energy savings and disinfection efficiency.
The emerging strategy of applying newer UV-C LED illuminators to sanitize surfaces, air, and water could have a profound effect, contributing to a cleaner, healthier world.