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UV disinfection

Using physics to solve a biological problem

Could ultraviolet light be an effective solution?

Ultraviolet (UV) light is a proven disinfectant against harmful viruses, bacteria, molds, and spores. As part of the electromagnetic spectrum, it’s invisible to the human eye and has the power to break down the RNA and DNA of viruses and bacteria so they can no longer reproduce or infect us. UV light can be used to disinfect air, surfaces, and water.

Germicidal UV light disinfection uses ultraviolet C, or UVC, light to reduce pathogens—including viruses and bacteria—in the air, on surfaces, and even in water.

Let’s start with a quick look at UV light.

UVA, UVB, and UVC: What’s the difference?

The ultraviolet spectrum of light is made up of 3 bands: UVA, UVB and UVC.

This graphic illustrates the 3 types of ultraviolet light the sun produces: UVA, UVB, and UVC


Around 95% of the sun’s rays that reach the ground are UVA rays. They have the longest wavelengths and can damage our skin, causing premature aging such as wrinkles and are thought to play a role in some skin cancers.


UVB rays make up around 5% of the sun’s rays, and while they don’t penetrate our skin as deeply as UVA, they can cause significant damage to our skin, including redness, sunburn, and skin cancer. We use sunscreen and wear sunglasses to protect our eyes and skin from both UVA and UVB rays.


Most UVC rays don’t reach the earth’s surface because they’re absorbed by the ozone layer. UVC has the shortest wavelengths that, at ranges below 230nm, aren’t able to penetrate beyond the top layer of our skin or eyes.

Can UVC light effectively reduce pathogens?

We know UVC light is highly effective in reducing pathogens. Businesses have long used germicidal UVC light to disinfect indoor spaces. However, because the typical 254nm UVC wavelength presents a human health hazard, it can only be used where protected people are present.

Can UVC technology reduce pathogens while people are present?

We need safe and effective technology for use in shared indoor spaces—from cinemas, theme parks, and casinos to public transportation, offices, businesses, schools, and labs—that can add a layer of defense as part of a multi-disinfection strategy like regular cleaning and washing hands.

Is far-UVC 222nm light a solution?

Promising new studies show that shorter UVC wavelengths—with the sweet spot being 222nm—have the unique ability to significantly reduce pathogens and may also be used around people.

Not all UV light is created equal

Christie CounterAct commercial UV disinfection fixtures contain Ushio Inc.’s patented Care222 lamps that emit far-UVC light that’s shown to significantly reduce pathogens. It’s the only far-UVC germicidal technology that may be used around people, and the only with a proprietary filter that prevents longer UVC wavelengths from being emitted.

Christie CounterAct products with patented Care222 technology are not for use as or for medical devices or for use on humans or animals or to disinfect medical devices.

This product is not intended to diagnose, treat, cure or prevent any disease.

Christie CounterAct products with patented Care222 technology and their pathogen reducing use in occupied spaces is dependent on proper installation and operational specifications, in accordance with American Conference of Governmental Industrial Hygienists (ACGIH) guidelines and IEC 62471.

Professional installation is recommended for Christie CounterAct products.

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 U.S. Food and Drug Administration and the U.S. Environmental Protection Agency.

The Care222® standard character mark and stylized logo mark are registered trademarks of Ushio America, Inc. in the United States, Japan, European Union, and United Kingdom.

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