It is a disinfection method that uses short wavelength ultraviolet light (UVCs) to inactivate or kill microorganisms and pathogens. UVGIs come from ultraviolet light with wavelengths short enough to be capable of disinfecting surfaces, air and water.
UV rays are known to damage the polypropylene from which masks are made. Is it acceptable to irradiate PPE?
UVCs can damage polypropylene masks or PPE. However, this takes time and long exposure. Research shows that we can safely irradiate and reuse PPE about 4 times with UV light before discarding them.
Absolutely! Patients, clinic staff and doctors pass on bodily fluids through toilets. There will be splashes. They gargle, clean their hands, mouth, and even their nose. Many aerosol droplets are generated. And the same toilets are used by other patients as well as by clinic staff.
That is why UVCs can be a quick disinfection option. Because toilets are much smaller than clinical rooms, disinfection is faster.
Ceiling tubes only have an 180 degree-radiation and lose energy on the wall. UV light loses considerable energy when it touches the wall or any other surface and has poor reflective properties for most materials. (except for aluminium, chrome, etc.) That is why equipments are generally closer to the center around which the maximum viral load can be found.
What if I keep a lower UV source than PuriTechs products for a longer period of time? Will it have the same effect?
Long hours of exposure to lighter UVCs can shorten the lifespan of plastics, mica and many other products. Dark objects may fade or lose colour and lighter objects may become more yellow.
USAGE OF UVC DEVICES
The effectiveness of UVC germicidal light depends on the length of time during which a microorganism is exposed to UVCs, as well as on the intensity and wavelength of the UVC radiation source.
As you may remember, old white equipment would turn yellow over time. This is due to UV exposure from natural light. Now, any good company tests their equipment for UV exposure. I myself have seen such UV exposure tests in many factories.
UVC light has been used in hospitals and surgical rooms for decades. Hospitals also have delicate and expensive equipment. That being said, UVCs can damage these equipments if exposure time is too long. Avoid using UVC lamps overnight.
Is it recommended to leave the UVC light running at night? If this is not a good option, how long does it take to kill germs?
This depends on what power of light you are talking about. But such 180-watt tube lamps are far too powerful!
The equipments would begin to tarnish.
The lengths of time necessary to kill various bacteria, fungi, spores and viruses are different. Usually, 15 minutes is more than enough to kill/inactivate all forms of micro-life with a 95 watt light in a 40 m2 room.
While some bacteria, spores and fungi take longer to inactivate, for most coronaviruses, 10 minutes of UVC exposure is sufficient in a 40 m2 room.
UVC light loses its germicidal energy when it falls on clear glass or plastic cases. For the same reason, many devices do not have glass protection.
If there is a glass cover, the device loses its function. UVC tubes should not be covered with anything.
It depends on the tube’s heating time, on its brand, on its age and on its power. Some UVC devices that use 36/40 watt germicidal tubes recommend a range of about 3 meters.
To further reduce shadows, you can remain in two opposing sides of the room and irradiate each side for 2-3 minutes. Circulating air (with a ventilator) while a UVC device is running will even help to irradiate air from all areas. UVCs at this power remain the fastest method of decontaminating rooms.
RISKS OF UVC RAYS
UVC rays with wavelengths of less than 290 nm are considered to have “germicidal” properties. The Earth’s atmosphere absorbs ultra-magnetic radiation of wavelengths of less than 290 nm, which means that most of the UVCs and UVBs generated by the sun are blocked by our planet’s ozone.
The distinction should be made between the biological effect and the depth of penetration of UVC radiation, a key concept in UVGI safety.
The cornea absorbs almost all ultraviolet radiation below 295 nm. This includes all UVCs and most UVB rays. Our natural crystalline lens absorbs most of the light close to UVBs (300-315 nm) and all UVA light.
UVC wavelengths are the most biologically active radiation and are, ironically, much less dangerous to humans. Indeed, UVC radiation is absorbed by the dead outer layer of human skin, whereas UVB and UVA radiation penetrates deeper. Although it is important to pay attention to UVGI safety, as “overexposure” to 254 nm, i.e. UVC rays, can easily cause erythema (“sunburn”) on the skin and photokeratitis (“welder’s flash”) in the eyes, long-term health risks are taken into account so as to be negligible compared to common UV exposures that have UVAs and UVBs.
Therefore, it is strongly recommended to leave the area where there are artificial UVC irradiation sources such as tube lamps, lamps, etc. There should be no direct exposure to light. Reflected light usually loses the majority of UVCs and consists mainly of visible light, which is thus safer.
Any device that solves this problem by adding an adjustable delay timer can be of great help. You can set a delay of 1 to 90 seconds depending on how long it takes you to leave the room.
An accidental look at UVC light at a distance of a few meters is acceptable. You are not looking at it for long. The eye lens does not allow UVCs to penetrate easily. An accidental glare is therefore acceptable. Again, distance is an important factor.
Can we look at the light through a glass door from another room? I have glass dividers in between the operators. Can I continue working while the UVC lamp is on in another room?
UVCs are very high-energy lamps with a shorter wavelength, but they lose energy faster than UVAs and UVBs.
Similarly, it cannot even cross normal glass. It loses its energy.
You can look at it through the glass door or the wall safely. Essentially, the light that passes through the glass is blue light minus UVCs.
UVC light does not pass through glass. It loses its energy when it touches the surface of the glass. What passes through glass is a visible blue-purple light. So do not worry!
Some companies sell UV rays with ozone formation options that also kill bacteria.
Ozone-producing tubes are actually cheaper. To stop ozone production, you need to filter wavelengths below 240 nm.
This makes ozone-free tubes more expensive. Although ozone is germicidal, it is harmful to our health. You have to recycle the air. It takes 45 minutes to remove ozone from a room. Our UVC system is germicidal, and does not emit any ozone.
We are tanned because of UV exposure when we go out into the sunlight. Can you tan at home? No. Can you get sunburnt at home? No!
Similarly, UV light is only dangerous when we are exposed to it. It is a light electromagnetic wave! UVAs and UVBs have much higher penetrative power than UVCs.
UVC light does not pass through the lens of the eye. So do not worry about accidental exposure.
UVC rays do not enter most surfaces. For decades, they have mainly been used in hospitals, theatres of operation and laboratories with very valuable equipment!