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Far-UVC light

The promising possibilities of 222nm

The disinfection technology we need right now

We need technology that inactivates harmful pathogens and helps people feel safe in indoor spaces—effective disinfection technology that adds a layer of defense as part of a multi-disinfection strategy like regular cleaning.

Urbanization, worldwide population growth, and global travel contribute to diverse contact among people, livestock, and wildlife, increasing the frequency and transmission of new pathogens that may harm us. We need safe and effective disinfection technology that reduces pathogens now, and for the future.

222nm: A sweet spot on the UV spectrum

Conventional germicidal lamps emit UVC light with longer wavelengths (>230nm) that also effectively reduces airborne and surface pathogens but present a human health hazard. What’s new is the discovery and application of far-UVC 222nm light, a sweet spot on the UV spectrum, to effectively inactivate pathogens with people present.

Recent research shows that far-UVC 222nm light—paired with an optical filter that prevents longer (>230nm) harmful wavelengths from being emitted—can reduce more than 99% of pathogens like SARS-CoV-2 (COVID-19) and influenza, as well as antibiotic-resistant bacteria like MRSA and E. coli, and allows for constant pathogen-reduction because it’s safer for use around people.

Read the far-UVC 222nm white paper

Read the Far-UVC 222NM white paper

What’s the difference between 254nm and 222nm far-UVC light?

This graphic illustrates why 254nm (and longer) wavelengths present a human health hazard to unprotected eyes and skin.

This graphic illustrates a significant difference between 254nm (and longer) and 222nm light: the shorter wavelengths of far-UVC 222nm light are unable to penetrate past the protective outer layers of our skin and eyes.

This graphic illustrates how far-UVC 222nm light inactivates airborne and surface pathogens like SARS-CoV-2 (COVID-19) by damaging its RNA. Not shown: The same light neutralizes bacteria by damaging its DNA.

Not all UV is created equal–and some is better together

Traditional UVC light isn’t new. It’s a proven technology that’s been in use since scientists in the late 1800s first investigated using sunlight to prevent the spread of airborne infections, and today it’s widely used in commercial disinfection systems. And while it's extremely effective against pathogens, its longer wavelengths (>230nm) can damage our eyes and skin if unprotected.

What’s new is the discovery of far-UVC 222nm light, a sweet spot on the UV spectrum that can effectively inactivate pathogens and run continuously around people because its shorter wavelengths are unable to deeply penetrate the protective outer layers of our skin and eyes. Care222® is also the world’s first UVC technology with a patented optical filter that blocks potentially harmful longer UVC wavelengths.

So what happens when you use both Care222 far-UVC light and upper room UVC-LED light in a single fixture? You get Christie® CounterAct UR10.

Christie CounterAct UR10 has you covered

The first-ever technology that uses both far-UVC and traditional UVC light, CounterAct UR10 ceiling-mounted fixtures offer dual protection. Care222 light shines downward to inactivate pathogens on surfaces, and traditional UVC kills airborne pathogens horizontally as air circulates across the ceiling. The result is enhanced, continual disinfection of both air and surfaces that makes us feel protected, feel normal when we gather in indoor spaces.

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Feel protected, feel normal with CounterAct UR10 UV disinfection products


Patented Care222 technology

Care222 excimer lamps produce far-UVC 222nm light

Here’s how: Care222 Krypton-Chloride (KrCL) excimer lamp modules contain a chamber filled with noble gas that doesn’t use inner electrodes and is completely mercury-free. High voltage applied across the outside of the glass excites the gas inside, causing far-UVC 222nm light to be emitted. And Care222 lamp’s construction allows them to instantly turn on or off without warm-up time or decreased lifetime, unlike other similar lamps.

The world’s first far-UVC technology with a proprietary optical filter

Care222’s proprietary optical filter prevents longer UVC wavelengths (>230nm) that present a human health hazard from being emitted—an especially important feature that other 222nm and far-UVC-emitting products don’t have.

Far-UVC 222nm: The disinfection technology we need now and for the future


Technology backed by research: What the studies say

Far-UVC (222nm) efficiently inactivates an airborne pathogen in a room-sized chamber

A March 2022 study by David Brenner et al. suggests that far-UVC should be an effective technology to reduce airborne disease transmission.

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The effectiveness of far-UVC light prototype devices with different wavelengths on disinfecting SARS-CoV-2

A November 2021 study conducted by researchers in Taiwan found that UVC-LED exhibited superior SARS-CoV-2 disinfection.

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Study on the disinfection and viral inactivation effects of 222nm UVC light using Care222

A July 2021 joint research project between Hiroshima University and Ushio Inc. showed that Care222 technology is equally effective in inactivating a SARS-CoV-2 variant as the original strain.

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Extreme exposure to filtered far-UVC: A case study

A January 2021 study by the University of St Andrews suggests that it’s critical for far-UVC devices to filter longer (>230nm) wavelengths for human skin safety.

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Exposure of human skin models to KrCL excimer lamps: The impact of optical filtering

A December 2020 study by Columbia University Medical Center supports the use of filters for far-UVC KrCL excimer lamps when used to limit disease transmission in occupied locations.

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Effectiveness of 222-nm ultraviolet light on disinfecting SARS-CoV-2 surface contamination

A Hiroshima University study published in September 2020 found that far-UVC 222nm light effectively reduced more than 99.7% of surface contamination of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the virus that causes COVID-19.

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All references to “disinfect”, “disinfecting”, and “disinfection” refer generally to the reduction of pathogenic bioburden and are not intended to refer to any specific definition as may be used by any governmental or regulatory authority, including the US Food and Drug Administration and the US Environmental Protection Agency. Christie CounterAct products with patented Care222 technology are not medical devices and are not to be used as or for medical devices. The pathogen-reducing efficacy of Christie CounterAct products and their use in occupied spaces is dependent on many site-specific factors as well as proper installation and operation within specifications and in accordance with the American Conference of Governmental Institutional Hygienists (ACGIH) guidelines. Professional installation is recommended for Christie CounterAct products. Ushio’s Care222® filtered Far UV-C technology (“Care222 Technology”) is protected under US and non-U.S. patents covering apparatuses and methods for inactivating viruses or killing bacteria with combinations of a light source and an optical filter that block potentially harmful UV-C wavelengths. Inventions in these patents are credited to Dr. David Brenner, et al., and assigned to Columbia University. Ushio Inc. is the worldwide exclusive licensee of these patents. “Christie” is a trademark of Christie Digital Systems USA, Inc., registered in the United States of America and other countries. This product uses Care222® technology developed by Ushio Inc. The Care222® is a trademark or registered trademark of Ushio Inc. and Ushio America, Inc.

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