Frequently asked questions

Ultraviolet (UV) light is a form of light, invisible to the human eye, that exists on the electromagnetic spectrum between X-rays and visible light. We are exposed to low levels of UV light from the sun every day, although much of the UV energy is absorbed by the ozone layer. Considered a natural disinfectant, UV light is divided into three bands: UVA, UVB and UVC. UVC, which is UV light with the shortest wavelengths has the strongest germicidal effect and is the one used for disinfection.

UV light penetrates viruses, bacteria and other infectious particles and destroys their DNA structure, making the microorganisms unable to multiply. When a microorganism is unable to multiply, it is considered dead since it cannot reproduce within a host and is no longer infectious. UV light destroys all microorganisms, including drug resistant bacteria.

UVC light, with wavelengths between 200 nm and 280 nm, has the strongest germicidal effect. The most effective germicidal wavelength occurs at a peak of 265 nm at which DNA absorbs UV light the most. Mercury-based lamps operating at low vapor pressure emit UVC light at 253.7 nm. UVC LED lamps emit UVC light at selectable wavelengths between 255 and 280 nm. PureFize® creates UVC light with a very broad germicidal spectrum with a peak wavelength at 262 nm*.

* Kowalski, W. "Ultraviolet Germicidal Handbook. UVGI for Air and Surface Disinfection." Springer-Verlag Berlin Heidelberg, 2009, p.17

To reach a certain level of disinfection you need a certain UV dose, which is a function of UV power and time. In other words, for a given application the higher the UV power used, the faster it goes. Many products are designed for a disinfection time in the order a few minutes or even less. When tested at Eurofins Laboratories, PureFize removed 99.9% (log3) of E. coli bacteria in 80 seconds and 99.9999% (log6) in about four minutes. As far as we know, PureFize is the only UVC technology that has reached log8 (a 99.999999% germ reduction), which is as close to real sterilization as it is possible. PureFize works in similar way on all bacteria, viruses and other germs, which means the object cleaned is safe for use after only a few minutes.

UVC lamps have been used for many decades to sanitize water, air and surfaces. Objects disinfected with PureFize are completely safe to use. However, UVC light should be kept away from skin and eyes because it can damage them and any other cells it comes into contact with, which is also how it kills microbes.

The safest type of UVC disinfection device is one that allows you to place items inside a closed space where the light will be used, which shields you from any accidental direct exposure. Any kind of shield, such as ordinary glass, plastic or even a wooden or paper box will stop UVC radiation. 

Conventional UV disinfection devices often rely on mercury lamps. There are also products that use UVC LEDs. PureFize is totally mercury-free and builds on the principle of field emission, which makes it very effective and at the same a much more sustainable solution.

Disinfection and sterilization are both decontamination processes. Sterilization is defined as a method that destroys or eliminates all forms of microbial life and is carried out in medical facilities. It is usually done through combinations of heat, irradiation, filtration, high pressure, etc. A product that has been sterilized is safe for use in an operating procedure or as an implant.

Disinfection describes a process that eliminates almost all harmful microorganisms. The level of disinfection is described using a standard called logarithmic (log) reduction. The table below shows log reduction levels with the corresponding germ reduction. As far as we know, PureFize is the only technology capable of reaching log8, which is as close to sterilization as you can come.

Disinfection by PureFize destroys all harmful microorganisms but it doesn’t take away dirt. Too much dirt or grease on a surface may shield the germs from the UV light. So yes, you still need to wipe off any dirt or debris before disinfection. Remember that UV disinfection won’t replace basic hygiene measures including hand washing. It also means that an item that has been disinfected with UV light will not look “cleaner”, as the microorganisms that have been destroyed are not visible to the naked eye.

You can find germs everywhere and most of them won’t harm you. Some bacteria that live inside your body (around 30,000,000,000,000 microbes comprising over 400 different species) are actually helpful. The bacteria on your skin, in your airways, and in your digestive system are the first line of defense against microbes that can cause infection. Some bacteria break down carbohydrates and toxins and help us absorb the fatty acids which cells need to grow.

We use bacteria daily to create food products such as yoghurt, cheese and vinegar. We are also able to use bacteria to break down our sewage and clean up oil spills. So, when we talk about a clean environment, we don’t mean an environment that is entirely free from bacteria and other germs.

PureFize light sources contain no mercury. No materials or substances harmful to the environment are used during manufacturing. The light sources have long lifespan and the entire system can be treated just like ordinary electronic waste.