top of page


Harnessing the Power of UVC Light

The use of Pure (non-additive) Technology



In the constant battle against harmful microorganisms, scientists and researchers are continuously exploring innovative methods to combat the spread of germs. One such is the use of ultraviolet-C (UVC) light.  Ultraviolet-C (UVC) radiation has effectively been used for decades to reduce the spread of viruses, bacteria, fungus and other pathogens. For this reason, UVC lamps are often called “germicidal” lamps. UVC radiation has been shown to destroy the outer protein coating of viruses, such as SARS-Coronavirus. UVC germicidal lamps work by producing short-wave ultraviolet light that disrupts DNA base pairing, causing formation of pyrimidine dimers, and leads to the inactivation of bacteria, viruses, and protozoans.

Understanding UVC Light

The Ultraviolet (UV) electromagnetic radiation spectrum ranges from 100 to 400 nanometer (nm). It is invisible to human eyes. UV is farther broken into 3 sub-spectrums:

  • UVA 315-400nm

  • UVB 280-315nm

  • UVC 100-280nm

One main source of ultraviolet light comes from our Sun. However, unlike UVA and UVB which can penetrate the Earth's atmosphere and pose potential health risks in long exposure time (like sun burns), UVC light is filtered out by the ozone layer and therefore does not affect viruses and other microorganism existence. In order to have UVC available, it needs to be artificially produced by UVC lamps. The UVC light spectrum is further broken into two segments: Far-UVC (100-230nm) and Near-UVC (230-280nm). 


The technology basics

In principle, inactivation of airborne viruses is done by passing the room air through a UVC light source.  Viruses exposed to this UVC radiation, will cause their genetic material to be damaged or destroyed. This helps reduce the risk of airborne transmission of viruses in enclosed spaces such as medical facilities, offices, and public transportation.

It is important to note that the effectiveness of UVC lamps in inactivating viruses depends on various factors, such as:

  • The specific range of viruses being targeted

  • Intensity of the UVC light

  • Exposure time to the UVC light

  • Distance from the light source

The sum of these factors produces an important value called Irradiance Dose.


Additionally, proper safety measures must be followed to protect human exposure to Near-UVC light, as it can be harmful to the skin and eyes.

Irradiance Dose

To reach a virus inactivation, we need to start with UVC dosage, because the ultimate goal is to achieve a certain UVC dosage needed to inactivate the virus. 

UVC dosage, also called exposure dosage or fluence, is a way to measure how much total UVC energy has radiated into a virus. This is the most crucial element in UVC system design, because UVC dosage is the primary determinant in whether or not we have successfully achieved virus inactivation.

Dosage is determined not only by the strength or intensity of the UVC light that falls on a virus, but also how long that virus is exposed to the UVC radiation for. In other words, all else being equal, a UVC lamp with half the strength can achieve just as much UVC dosage if it is used for twice the amount of time.

The intensity of the UVC that falls on a virus is called irradiance and is measured in W/m² (or some variant of power per surface area). The exposure time is measured in seconds.

The simple form of the formula is :
Exposure Dosage (J/m²) = UV Irradiance (W/m²) x Time (seconds), or 1 Joule = 1 Watt-second.


However, distance from the UVC light source is a major consideration. The irradiance values are higher the closer one is to the UVC source, and the closer one is to the perpendicular axis.  The irradiance value may drop exponentially with increased distance from the UVC source.

Pure Air Technology

Pure Air technology is a method of inactivating viruses without adding to or changing the room air content, keeping the room air pure. Other methods including the addition of Positive or Negative Ions, fragrance or introducing free radicals to the air. These are considered Additive Technologies and introduce some risks to human health.

About Additive Technologies

PURE-V products do not add any by-product to the airflow. There are other companies that market products with technologies that add by-products into the airflow.


Here are few examples of added by-product components:

Titanium Dioxide and UVC: 

Titanium dioxide (TiO2) in combination with ultraviolet C (UVC) light has been explored as a potential method for germicidal activity and air purification. It is used in air purification apparatuses that use low-intensity UVC lamps or UVC LEDs.   While this technology holds promise, it is important to consider the potential risks associated with its use. Here are some of the risks associated with TiO2-UVC systems:

  1. Production of Harmful Byproducts: When TiO2 is exposed to UVC light, a chemical reaction occurs, leading to the production of reactive oxygen species (ROS) such as hydroxyl radicals and hydrogen peroxide, and other free radicals that can interact with nearby molecules, including organic pollutants in the air. While these ROS and free radicals contribute to the germicidal properties of TiO2-UVC systems, they can also have harmful effects when present in high concentrations. Prolonged exposure to high levels of ROS can cause oxidative stress, cellular damage, and potential harm to the respiratory system, while other free radicals produced in the process may be a source for cancer.

  2. Formation of Volatile Organic Compounds (VOCs): In certain conditions, TiO2-UVC systems can lead to the formation of volatile organic compounds (VOCs). VOCs are organic chemicals that can vaporize at room temperature and contribute to indoor air pollution. Some VOCs have been associated with health effects such as respiratory irritation, allergies, and even long-term health risks.

  3. Maintenance and Operation Challenges: TiO2-UVC systems require regular maintenance and careful operation. The effectiveness of these systems can be affected by factors such as dust accumulation on TiO2-coated surfaces and degradation of the TiO2 coating. Failure to adequately maintain and operate these systems may result in reduced germicidal efficiency or increased risks associated with byproduct formation.

  4. Environmental Concerns: The disposal of TiO2-coated materials raises environmental concerns. TiO2 is a nanoparticle that has the potential to accumulate in the environment and may have adverse effects on ecosystems. 

Positive and Negative Ions:

Positive ions in the air have been a topic of debate in terms of their impact on human health. Positive ions are created through various natural processes, such as radiation, sunlight, and moving air, but they are also generated by human-made sources like electronic devices and air pollution.

Some proponents suggest that positive ions can have negative effects on our health. They argue that excessive exposure to positive ions, particularly in enclosed spaces or areas with high pollution levels, may contribute to fatigue, respiratory issues, allergies, and a generally negative impact on our well-being. However, it is important to note that the research supporting these claims is limited and often inconclusive.

On the other hand, negative ions (not positive ions) have received more attention in scientific literature. Negative ions are abundant in natural environments such as forests, waterfalls, and beaches. Some studies have suggested that negative ions can have a positive impact on our health and well-being. They are believed to potentially enhance mood, improve air quality by attaching to and neutralizing pollutants, and provide a sense of relaxation and well-being.

While some air ionizers or purifiers claim to generate negative ions, it's important to note that their effectiveness and health benefits are still under scrutiny. The concentration of ions, whether positive or negative, in the air can vary depending on the location, weather conditions, and human-made factors.

In conclusion, the impact of positive ions on human health is not well-established. The potential health benefits associated with negative ions are more widely discussed, but further research is needed to fully understand their effects. In any case, maintaining a balanced and healthy indoor and outdoor environment, including proper ventilation and air quality control, is crucial for overall well-being.

Fragrance generator:

Oil-based air purifiers, commonly known as fragrance or aroma diffusers, release scented oils into the air to create a pleasant aroma. While they may provide an appealing fragrance, their impact on health depends on various factors.

Some scented oils used in these devices may contain volatile organic compounds (VOCs) that can contribute to indoor air pollution. These VOCs can be released into the air and potentially cause respiratory irritation or allergic reactions in some individuals, especially those with sensitivities or pre-existing respiratory conditions.

Additionally, certain synthetic fragrances used in oil-based air purifiers may contain chemicals that can be harmful when inhaled or come into contact with the skin. These chemicals can include phthalates, which have been linked to adverse health effects.

Furthermore, prolonged exposure to strong fragrances can trigger headaches, migraines, and other symptoms in individuals who are sensitive to scent.

Ozone generating:

Stand-alone or part of an air purifier ozone generators are devices that produce ozone, a molecule composed of three oxygen atoms, and release it into the air. These devices are often marketed as air purifiers or cleaners, claiming to remove odors, kill bacteria, and improve indoor air quality. However, the use of ozone generators raises significant health concerns.

Ozone is a highly reactive gas that can interact with various substances, including pollutants, in the air. While ozone can be beneficial when present in the Earth's upper atmosphere, at ground level, it can have harmful effects on human health.

Exposure to elevated levels of ozone can cause respiratory irritation, coughing, shortness of breath, and worsen existing respiratory conditions such as asthma or bronchitis. Prolonged or significant exposure to ozone may also damage lung tissue and compromise lung function. People with respiratory conditions, children, the elderly, and individuals with weakened immune systems are particularly susceptible to the adverse effects of ozone.

Due to the potential health risks associated with ozone generators, several reputable health organizations, including the United States Environmental Protection Agency (EPA) and the Occupational Safety and Health Administration (OSHA), have issued warnings against their use. The EPA has stated that ozone generators are not appropriate for residential use and can pose serious health risks.

In summary, ozone generators are not considered healthy and can have detrimental effects on human health. It is advisable to avoid using ozone generators and instead opt for safer and more reliable methods to improve indoor air quality.

bottom of page