Acuity partners with Ushio to embed UV excimer lamps for disinfection in SSL

Acuity Brands and Ushio have announced a partnership whereby Ushio will supply Acuity with Care222 UV (ultraviolet) disinfection modules for integration into lighting products such as wall- and ceiling-mounted LED luminaires. As the model number of the Ushio module implies, the units deliver 222-nm UV emission that is part of the UV-C band (100–280 nm) but that consists of much shorter wavelengths than typical germicidal UV products that emit in the 250–280-nm range. The shorter wavelength emission is suddenly of great interest because recent research indicates that the so-called far-UV energy may be safe for human skin and eyes and also may kill the coronavirus as well as other pathogens.

Acuity will evidently have exclusive rights in North America to sell general solid-state lighting (SSL) products that integrate the far-UV capability. Acuity will also be allowed to offer such products in other regions on a non-exclusive basis except in Asia. The Ushio modules are based on excimer laser technology and are often referred to as excimer lamps.

Since the onset of the coronavirus pandemic, we have been beset with press releases about the use of UV to kill the virus. In many cases, we have judged the announcements as barely-veiled attempts to cash in, if you will, on the COVID-19 scare and we have carefully vetted what we publish on the topic.

The germicidal properties of UV-C emission are well known, but so too are the dangers to human skin and eyes. We only began hearing about this far-UV potential a month or two back. Research on the safety to humans and the ability to deactivate viruses and bacteria is limited, yet comes from impressive institutions — Columbia University in the US and Kobe University in Japan. The research shows that in humans, already-dead skin cells absorb the far-UV energy before it can do damage and the radiation is absorbed in the outer surface of the cornea in the eye. (Editor’s note: Currently, there is a work on the potential of far-UV-C by Columbia University Irving Medical Center researchers under review status as a pre-print, available to read on the ResearchSquare website.)

Ushio has promoted the far-UV technology primarily for use in unoccupied spaces just as germicidal UV-C is safely deployed. But the company has said it believes the emission to be safe for humans. We have been working to get a feature article written on the topic to answer more questions and hope to have that for you soon. We would generally suggest that more research might be needed on the topic, but Acuity would not have struck this deal without having a pretty good idea that it was safe.

“In recent years, it has become increasingly paramount to find new, safer methods of reducing pathogens on surfaces throughout the day,” said Rick Earlywine , senior vice president at Acuity Brands Lighting. “We are excited about incorporating the Care222 UV light module into our lighting fixtures for use in both occupied and unoccupied spaces. Using this module in our leading lighting fixtures installed in a space represents a significant advancement in protecting public areas against bacteria and viruses.”

Now understand, that this far-UV lamp has nothing to do with lighting. You may hear people talk about lighting disinfection. And there are lighting products that emit in the human visual range and that can slowly kill pathogens, yet not necessarily the coronavirus. The Care222 UV produces no visible light. The light fixture in the Acuity case is simply a convenient place to deploy the disinfection technology. Light fixtures are ubiquitous in all types of spaces from offices to medical facilities to restaurants and more, and power is readily available.

The lighting and far-UV systems for the moment will be largely independent. Acuity will have to incorporate a control system to separately handle both. The company said the Care222 UV lamp will be pulsed on intermittently to perform the disinfection function. The lighting function could be on or off during such disinfection pulses.

Ideally, you could integrate far-UV LEDs alongside visible-light LEDs in such a fixture. In that case, you could use a unified driver and control system for both functions. But far-UV LEDs aren’t available now. The only other option for producing far-UV emission would be a mercury lamp and of course those products include hazardous materials. The excimer products do not.

This is not Acuity’s first foray into disinfection. The company had previously signed a license agreement to use Vital Vio’s continuous disinfection technology. Such a product would have used visible light, may not have been capable of destroying viruses, and would not have worked instantaneously to kill pathogens but over prolonged exposure periods. We don’t know the status of any product based on that license agreement as Vital Vio has battled Kenall in an intellectual property dispute on the technology.

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