Far-UVC vs Traditional UVC: What Businesses Need to Know About Emerging UV Technologies

Ultraviolet (UV) technology has long been used as an effective method for disinfection across air, water, and surface applications. Traditional germicidal UVC systems, typically operating at a wavelength of 254nm, are widely recognized for their ability to inactivate microorganisms. More recently, emerging far-UVC technology has gained attention as a potential advancement in UV disinfection. Understanding the differences between these technologies is important for businesses evaluating current and future disinfection strategies.

What Is Traditional UVC Technology

Traditional UVC disinfection relies on ultraviolet light in the 254nm range to disrupt the DNA and RNA of microorganisms. When exposed to the appropriate intensity and duration, pathogens such as bacteria, viruses, and fungi are rendered inactive and unable to reproduce.

This technology is well established and widely used in applications such as:

• HVAC air purification systems
• Municipal and industrial water treatment
• Surface disinfection in healthcare and cleanroom environments

Traditional UVC systems are highly effective when used in controlled settings where direct exposure to people is limited or managed through system design.

What Is Far-UVC Technology

Far-UVC refers to ultraviolet light in the shorter wavelength range of approximately 200 to 235nm. Like traditional UVC, far-UVC light can inactivate microorganisms by damaging their genetic material. However, its shorter wavelength results in different interaction characteristics with biological tissues.

Research suggests that far-UVC light has limited penetration depth, meaning it may not reach or damage living human cells in the same way as traditional UVC wavelengths. At the same time, it remains effective at targeting smaller microorganisms such as bacteria and viruses.

This has led to increased interest in far-UVC as a potential option for disinfection in occupied spaces, although ongoing research and regulatory evaluation continue to shape its adoption.

Key Differences Between Far-UVC and Traditional UVC

While both technologies are designed to inactivate microorganisms, there are several important differences:

• Wavelength range

Traditional UVC typically operates at 254nm, while far-UVC operates between 200 and 235nm

• Application maturity

Traditional UVC is widely deployed and proven across industries, while far-UVC is still emerging

• System design considerations

Traditional UVC systems are often installed within enclosed or controlled environments, whereas far-UVC systems are being explored for use in occupied spaces

• Performance and validation

Traditional UVC has extensive field data supporting its effectiveness, while far-UVC continues to be evaluated through ongoing studies

These distinctions are important when selecting a technology that aligns with current operational needs and regulatory requirements.

Current Applications and Considerations

Traditional UVC remains the standard for most commercial and industrial disinfection applications due to its proven reliability and well-established performance. It is commonly used in systems where exposure can be controlled, such as inside HVAC ducts or water treatment chambers.

Far-UVC technology, while promising, is still in earlier stages of adoption. Businesses considering its use should evaluate factors such as regulatory guidance, system design requirements, and the availability of validated performance data.

In many cases, traditional UVC systems continue to provide the most practical and cost-effective solution for immediate disinfection needs.

Looking Ahead: The Future of UV Disinfection

As research and development continue, both traditional UVC and far-UVC technologies are expected to play roles in the future of disinfection. Advances in lamp design, materials, and system integration are expanding the possibilities for how UV light can be used safely and effectively across a range of environments.

For businesses, understanding the capabilities and limitations of each technology is essential for making informed decisions. While far-UVC represents a developing area of innovation, traditional UVC remains a reliable and widely implemented solution that continues to support critical disinfection applications.

Manufacturers with expertise in UV lamp engineering and OEM solutions are helping to drive these advancements by developing technologies that meet evolving industry needs. Through continued innovation, UV disinfection systems will remain an important part of strategies to improve safety, efficiency, and environmental performance.

222 nm UV Light: Far UVC Effectiveness and Safety

Ultraviolet light in the UVC range is proven to have germicidal properties, with 222 nm UV light showing high efficacy and safety. Standard UVC germicidal lamps emit wavelengths at 254 nm, proven to have high germicidal effectiveness by breaking the DNA bonds inside the nucleus of harmful microbes and pathogens. 254 nm UV lamps, however, are not safe to use when humans are present and pose risks to damaging skin and eyes.

222 UV lamps are showing the same germicidal properties and are much safer than 254 nm lamps due to the way 222 nm wavelengths are absorbed by the protein layer of cells. 222 nm UV light is also known as Far UVC and is considered safe to use around humans without risk of human exposure to skin or eyes.

222 nm UV Light Effectiveness

Both 222 nm and 254 nm UV lamps emit UVC wavelengths that inactivate viruses and bacteria. 222 nm UV light penetrates the microbe’s cell nucleus and breaks the DNA bond to prevent replication, thus rendering the cell harmless, the same as 254 nm UV lamps. 222 nm UV lamps go even further than inactivating the cell, however, and actually destroy pathogens.

When standard UVC lamps inactivate pathogens, there is a possibility that they could be reconstituted through a process called photoreactivation. This is not possible with 222 nm UV light which is known to deactivate and destroy most harmful human pathogens, including bacterium, viruses, fungus, mold, protozoa, and prions. Far UVC light has been the focus of many studies for over a decade, with many research studies showing high efficacy against a wide range of known harmful pathogens, including alpha and beta coronaviruses, influenza (H1N1), and adenovirus.

222 nm, Far UVC light is shown to safely and effectively inactivate human airborne coronaviruses, with research showing effectiveness at killing the SARS-CoV-2 virus that causes COVID 19. The study showed that even low doses of far UVC light inactivated 99.9% of aerosolized coronavirus. Much research has been conducted on the effectiveness of standard germicidal lamps for SARS-CoV-2, showing that UV light does kill COVID in air and on surfaces.

Far UVC lamps designed to emit 222 nm are also called Excimer lamps and are in use today in many applications, providing UVC germicidal protection with significantly safer operation.

222 nm UV Lamps: Excimer Lamp Effectiveness

Excimer lamps that emit 222 nm UV light are produced by creating a high-voltage discharge in a glass tube lamp with the proper mixture of gases to create 222 nm when energized. The intensity of the output can vary depending on the input power, and an optical filter can be included to ensure that harmful wavelengths above 230 nm are removed. 222 nm Excimer lamps are showing high effectiveness at killing viruses on surfaces, in the air, and safely inactivating airborne human coronaviruses.

Safety of 222 nm Far UVC Light

222 nm Far UVC light is highly effective at destroying harmful pathogens and is opening the door for many uses beyond traditional germicidal lamps due to the ability to operate safely in the presence of humans. 254 nm light used in standard germicidal lamps is absorbed by DNA to kill harmful cells but is not easily absorbed by proteins, which means it can penetrate deeper into human skin and damage the DNA of actively dividing skin cells which can lead to cancer.

222 nm UV light, however, is also highly absorbed by DNA but is also absorbed by proteins, which are contained in the outer membrane shell of all viruses and bacteria. This increases the effectiveness of 222 nm light against some microbes while also making it much safer for use around humans. Since 222 nm light is absorbed by proteins, it will not fully penetrate into the thick protein-rich layer of human cells.

The outer layer of human skin consists of dead skin cells with no active cells and provides an armored layer against 222 nm light. A similar layer of cells protects the eyes. Since 222 nm UV light never reaches the DNA of actively dividing cells, it is safer for use and human exposure.

HVAC UV Bulbs Improve Indoor Air Quality

Many people want to know if HVAC UV bulbs really work to improve indoor air quality in heating, ventilation, and cooling (HVAC) systems. HVAC UV light bulbs can be highly effective at killing bacteria, viruses, mold, mildew, and fungi when using the right type of germicidal UV bulbs and with the proper installation.

Do HVAC UV Bulbs Really Work?

HVAC UV light bulbs prevent the accumulation of harmful microbes on internal components such as heat transfer coils which are exceptionally vulnerable to contamination due to the dark environment combined with condensation. Using HVAC UV light bulbs helps to improve the condition of mechanical components and reduce necessary maintenance by maintaining clean and sanitary parts free from microbial buildup.

HVAC UV bulbs also improve indoor air quality by sanitizing the air and inactivating mold spores that pass through HVAC ductwork. Ozone lamps in HVAC systems can also reach where direct UV exposure cannot and eliminates volatile organic compounds (VOCs) and foul odors from the air. Using UV bulbs in HVAC systems helps prevent harmful microorganisms from circulating throughout the ductwork in your home or office.

UVC Germicidal Bulbs for HVAC

HVAC UV light bulbs must be UVC germicidal bulbs to provide sterilization effectiveness. Ultraviolet light includes wavelengths in the range of 100 to 400 nm and is divided into three bands:

• UVA is the longest wavelengths at 315 to 400 nm
• UVB is in the range of 282 315 nm
• UVC wavelengths are in the range of 100 to 280 nm

UVC radiation, specifically in the range of 254 nm, is proven highly effective at eradicating microorganisms quickly upon exposure by altering the DNA and preventing harmful germs from replicating. UVC radiation in this wavelength is proven to eliminate many types of harmful viruses and bacteria, including stubborn antibiotic-resistant bacteria and harmful coronaviruses, including the SARS-CoV-2 virus that causes COVID-19.

Far UVC is an even shorter wavelength in the range of 222 nm and is also effective for surface and air sterilization applications, and is safer for human exposure. 254 nm lamps are used in many surface, water, and air sterilization applications, although they should not be used in direct contact with human exposure. 222 nm lamps are providing alternative solutions with effective sterilization and safer usage.

HVAC UV Bulbs Improve Indoor Air Quality

UVC lamps for HVAC systems improve indoor air quality when installed by a professional to ensure safe and effective installation. HVAC professionals have knowledge of the correct placement and direction of UV bulbs for effective sterilization, considering the humidity and temperature levels in the home. Upper-Room Ultraviolet Germicidal Irradiation (UVGI) systems are located above occupied spaces and kill airborne pathogens for cleaner, healthier air.

UVGI and Air Filtration Filters

The Centers for Disease Control and Prevention, CDC, recommends a layered approach with the proper ventilation to mitigate the spread of disease and lower exposure. Using High-Efficiency Particulate Air (HEPA) is important to trap larger particles which could shield microorganisms from UV radiation, reducing effectiveness. UVGI provide effective sterilization but should be used in conjunction with proper air filtration and cleaning measures, and they do not replace the need for HEPA filtration.

HVAC UV Light Bulb Systems

HVAC UV bulbs provide two different types of sterilization, cleaning the coils and equipment for longer-lasting, cost-efficient operation and air sterilization in HVAC ducts. UV bulbs for HVAC disinfectants sterilize the air as it cycles through return ducts. Interior reflective surfaces maximize UVC light effectiveness in all directions. For sterilizing coils, UVC lamps are installed to target vulnerable components, including coils, filters, and condensation pans. UV light for HVAC systems prevents microbial growth in hard-to-reach places, including seams, grooves, and edges.

UVC Virus Killers: Germicidal Lamps and Far UVC

The ongoing COVID-19 pandemic continues to stress the importance of utilizing effective Infection Prevention and Control (IPC) methods, and germicidal lamps are gaining in popularity as UVC virus killers.  Ultraviolet (UV) based technologies are promising IPC tools showing high efficacy in killing many types of beta coronaviruses, including the SARS-CoV-2 virus that causes COVID-19.

As of March 29, 2023, the toll of the global health pandemic as reported by the World Health Organization, WHO, reports 761,402,282 confirmed cases of COVID-19, including 6,887,000 deaths in 229 countries and territories and 102,697,566 confirmed cases of COVID-19 with 1,117,054 deaths in the United States.

UVC Virus Inactivation and Efficacy in Reducing the Spread of Disease

The Federal Drug Administration, FDA, offers additional information for businesses and consumers to learn more about ultraviolet light virus inactivation and its efficacy in reducing the spread of disease. UVC radiation at the correct wavelength has been used for decades for the effective disinfection of air, water, and surfaces and is engineered in UVC germicidal lamps. UV-C light kills bacteria such as tuberculosis and many viruses, including beta coronaviruses.

UV-C Light Kills Viruses MERS, SARS, and SARS-CoV-2

Coronaviruses are a large family of viruses that typically cause mild-to-moderate respiratory infections in humans, although coronaviruses are known to infect both humans and animals. They can often spread in animals but can jump to humans and continue spreading in humans with viral mutations. Coronaviruses are named partly due to the crown-like spiked protrusions on the surface.

Some types of coronaviruses may cause illnesses like the common cold, although severe acute respiratory syndrome viruses (SARS-CoV) can be severe, such as the fatal outbreak of SARS in 2002 and Middle East Respiratory Syndrome coronavirus (MERS-CoV) in 2012. SARS-CoV-2 is another severe acute respiratory syndrome virus that causes COVID-19.

Ultraviolet light virus inactivation is highly effective at eliminating the threat of coronaviruses, including the SARS-CoV-2 virus, when administered at the proper wavelength and dosage. According to a scientific report, UV-C irradiation is highly effective in inactivating SARS-CoV-2 replication; the response of UV virus inactivation depends on both the virus concentration and the UVC dose. The results of this study and many others show that the SARS-CoV-2 is extremely sensitive to UVC light.

UVC Light Kill Viruses And Other Harmful Pathogens

According to a study published in 2020 and reported by Biological Consulting Services, UVC virus inactivation was determined against various harmful pathogens with results including:

• Influenza A H1N1 – 99.999% reduction
• SARS-CoV-2 virus – 99.999% reduction
• Polio Virus LSc 1 – 99.99% reduction
• Methicillin Resistant Staphylococcus Aureus (MRSA) – 99.99 reduction
• Salmonella species, 6 variations – 99.99% reduction

UV virus elimination is very effective when using the right type of UVC germicidal lamps and the proper dosage, and environment such as line of sight disinfection on a surface not contaminated with dirt that can affect UV inactivation results. This is why ultraviolet light virus disinfection is recommended in addition to manual cleaning practices for maximum effectiveness.

UVC Virus Disinfection in Air, Water, and Surfaces

UVC germicidal lamps are typically designed to emit wavelengths at precisely 254 nm, proven to be highly effective at penetrating the DNA of microorganisms to render them harmless. Far UVC lamps are gaining in popularity and showing high germicidal efficacy while being safer to operate in the presence of humans. Standard germicidal UVC lamps should operate in non-occupied spaces and can be found in upper room ultraviolet germicidal irradiation (UVGI) systems, HVAC systems, and other disinfection devices like UVC robots programmed to run through hospital hallways or patient rooms that are unoccupied.

Not all UVC germicidal lamps are created equal, and it is important to work with an experienced ultraviolet lamp designer to ensure effective germicidal properties.