Questions and Answers

Questions and Answers on UV-C Disinfection webinar

Does UV-Light actually exist?: The definition of UV-Light is the electromagnetic radiation with the wavelength between 100 and 400 nm.
So the fixtures currently installed in restaurant kitchens with blue-ish up light is UV-A for attracting bugs, not UV-C for air sanitation?: Correct.
How do we get 3rd party reports confirming the wavelength of our UVC Lamps / Products?: If you use Signify products, Signify will provide those reports. External laboratories such as TNO or Universities can provide independent reports.
How we can disinfect the medical equipment like portable xray, ultrasound by using UVC? What will be the methodology for it?: To our knowledge there are no UV-C based methods that are released for disinfection of medical products. This equipment needs to be disinfected with traditional methods such as alcohol etc.
Hi, I would like to ask: Who are the other players that are working on the same technology?: Main companies are LSI/Lightech, Osram and a number of other small players.
Generally, the artificial UVC lamp has only been used for disinfection and germicidal application. It was believed that UVC caused cancer and naturally blocked by Ozone layers. Do you have strong evidence to support for general use of UVC?: UVC has been widely used for many years in purification of drinking water as well as disinfection of air. Because of the potential harmful effect of UV-C lamps, use should be restricted in such a way that humans are not directly exposed to the light.
Is UV-C better in filtering air than HEPA filter in air handling units / ducts, considering the size of viruses (Covid -19 aprox. 0.125 microns) ?: HEPA filters (various classifications) are also very effective in air handling unit as long as the particles are larger than 0.3µm. Also the higher the classification of the filter, the more air pressure is lost due in HVAC system, so more power is needed to create the airflow. UV-C does not have these limitations and so is interesting to be used -very often in combination with a HEPA filter
There are real studies that UV-C kills COVID-19?: Yes, there is a university study published today that proves the capability of UV-C to inactivate SARS-Cov-2, the virus that causes Covid 19
In simple terms, is exposure to normal sunlight a good source of UV-C as a 'treatment' against C19?: The atmosphere filters out UV-C. UV-A, which is part of normal sunlight, is giving you the tan of the skin but over exposure (over longer periods of time) can lead to skin-cancer.
Is there any certification from approved labs that show the effectiveness of this lens uv-c?: There is a university study published today that proves the capability of UV-C to inactivate SARS-Cov-2, the virus that causes Covid 19. Generally products are not certified though.
Good afternoon, thank you for the interesting topic. Do you know, whether it would be possible to use UVC to disinfect saliva samples collected with cotton swabs within plastic tubes (salivetttes)?: The likelihood that this will be effective is low, as UV-C only disinfects the surface. In cotton swabs the infected materials may reside inside and therefore UV-C will most probably not reach all germs. As such this application should not be using UV-C.
What about healthcare, senior facilities, group homes, prisons?: All above can have potential application of UV-C.
What effect does UV-C have on food? Example: if a mobile unit were used in a classroom and an apple were on the teachers desk - what would happen to the apple?: The effect of UV-C on food is small with short exposure. The germs and molds on the food will normally be inactivated. Prolonger exposure will be detrimental to the quality of the food.
Does UV-C reflect on mirror or shiny surface?: Yes , with one precision: In case the mirror is made of metal than it reflects. If it is made of glass, it doesn’t.
Even if we put UV lamp upward, is it still harmful from reflected radiation? Do we have to consider reflectivity of materials?: Yes, this needs to be taken into account when designing the application of UV-C lamps and fixtures. IN practice , best to perform measurements in order to assess if max. allowed dose will not be surpassed.
How does UV affect materials such as plastic, wood or other metals? Does it cause brittleness or deterioration in them?: The effects of UV-C differ per material. Some materials are sensitive to them, others are not. In some materials UV-C radiation may cause change of color, reduced shininess or even brittleness. Ashrae publishes in their UV-C handbook the sensitivity of materials to UV-C.
How do you use UV-C when the heat is on?: The definition of UV-Light is the electromagnetic radiation with the wavelength between 100 and 400 nm.
So basically the UV-C are used in a high sensitive areas that require high disinfection level?: Not necessarily. UV-C can also be used in areas that don’t need high disinfection levels or that are not sensitive. Having said so, the effectiveness of UV_C is such that within relative short period of time high disinfection levels can be reached (99,9% or higher)
When do you think the Far-UVC lamp would be widely used in combat Covid-19?: We expect that commercial availability in sufficient quantities will not be before 2021.
How to calculate UV dose?: It is Irradiance x time (see ‘calculations’ part of webinar)
You UV will need to be when no humans, domestic animals, & plants?: Yes, no humans, no domestic animals. Plants can have very limited exposure. Example for plants in greenhouses and on Grass pitches are UV-C is sometimes used to stop growth of moulds.
Is this also good for Legionnaires disease?: Yes, if the water is disinfected with UV-C, legionella will also be inactivated.
Does upper air disinfection clear viruses from the air that people breathe? Will it help reduce respiratory transmission?: Yes, it does. The time required to disinfect the air depends of course on the installed system but also on the airflow itself
Do UV-C Lamps contain mercury? If so, what about the adverse affects of mercury and the environment?: Yes. All discharge lamps contain mercury. Being the leader in lighting, Signify has been able to reduce the dosage of mercury to a minimum in the same way it is done for the much wider used fluorescent lamps. In addition lamps may also be recycled.
What is approx. time, an item will be disinfect by UV-C rays: UV-C light should never be used while exposing people directly. As a result it will not act on clothing. However, if clothing would be put directly under UV-C, discoloration may occur.
Paul told us that germs are everywhere and we find them in many places. Suppose a person enters a shopping centre. Does UV-C light also act on your clothing?: UV-C light should never be used while exposing people directly. As a result it will not act on clothing. However, if clothing would be put directly under UV-C, discoloration may occur.
It seems to work, but how do we see how these systems are useful to disinfect? What is the evidence that there is no side effect by this system? Who is going to review this system and approve for the public safety and wellbeing?: UV-C has already been in use for over 30 years, in many applications such as water and air disinfection.

UV-C can be harmful for the human eye (“snow blindness’) and can cause severe sunburn of the human skin. That’ s why appropriate safety measures need to be taken.

These safety requirements have been defined by various international bodies like IEC and ACGHI, as well as by IUVA, the international non-profit association around UV
What would be the effect in the closed luminaire?: UV-C will not pass through when it is in a closed luminaire. When choosing materials for a fixture, one must pay attention to select UV-C resistant materials in case these will be exposed to the radiation of the lamp.
In the bathroom of my office how many times it is neccessary to disinfect per day, every time someone uses it? The use is constant. We are many people.: The answer depends on the effect you want to achieve. Most effective would be to disinfect after each time someone used the bathroom.
Do we have any test Certificates as a proof for the Solution like batten/Robots/Cabinets etc.: The equipment itself needs to fulfill safety aspects as described in IEC , UL. There are no specific UV-C regulations on the equipment

Questions and Answers

Questions and Answers on UV-C Disinfection webinar

We'd love to hear from you