THE AMBITIONS of the lighting industry to be a major supplier of UV-C products was given a boost today as 239 scientists declared that airborne transmission of the coronavirus is much more significant than previously thought.
In an open letter to the W.H.O., the researchers from 32 countries outlined the evidence showing that smaller particles can infect people, and are calling for the agency to change its recommendations from an emphasis on hand washing.
The scientists – who plan to publish the letter in a scientific journal next week – suggest that emphasis should move from surfaces to indoor air as the significant medium of transmission.
The letter has received global publicity, including an extensive feature in the New York Times.
A shift in emphasis from surfaces to air will be welcomed by the lighting industry.
UV-C light – which breaks the DNA of micro-organisms (RNA in the case of the coronavirus) and makes them harmless – are more effective targeting pathogens in the air than on surfaces.
UV-C light degrades materials, and surfaces in shadow do not experience the disinfection provided by the UV-C light. Additionally, UV-C light targeted at surfaces could more easily come in contact with humans, for whom it is very harmful.
By contrast, properly-designed upper-air disinfection – where air-borne viruses are killed by UV-C light from light sources mounted safely above and invisible to occupants – isn’t harmful to surfaces or humans.
Recently, scientists at Boston University confirmed that medium-pressure mercury vapour lamps – which emits UV-C at a wavelength of 254 nanometres – can kill the coronavirus ‘in seconds’.
In a recent statement, the Illumination Engineering Society agreed that targeting indoor air was the way forward: ’While UV-C could be a secondary infection control measure for disinfecting potential germ-carrying deposits on accessible (not-shadowed) surfaces, its great value would be in disinfecting air in areas where this may be a concern’.
‘Upper-air germicidal ultraviolet is the safest, most effective application of UV-C’.
The big lighting brands are betting heavily on a lucrative emerging market for upper-room UV-C lighting systems.
Signify chief Eric Rondolat recently told Lux that he envisions a booming market: ’We believe this is a fabulous potential moving forward’.
The company is not revealing how much it is investing.
Osram recently gained international approval for its UV-C mercury lamp range and says 2,000 units of its Chinese-made UV-C lamp, the AirZing, are already in use in hospitals in Wuhan and Beijing.
Its factory in Kunshan has a capacity of 35,000 units per month, but management are exploring ways to increase this number.
The lighting industry is also gearing up to produce other UV-C-based products including mobile, freestanding UV-C luminaires that can be wheeled into a hotel room or used to disinfect surfaces on public transport such as buses and trains and disinfection chambers for phones, bags, laptops and wallets.