First let’s begin with what UV light is. Ultraviolet light is electromagnetic radiation of wavelengths just below the spectrum of visible light (400–780 nm). It is subdivided into three groups: UV-A with a wavelength of 315–400 nm, UV-B with 280–315 nm, and UV-C with 100–280 nm. The smaller the wavelength the more energetic the radiation. Next to its visible spectrum the sun also emits UV light. However, in contrast to the UV-A and -B rays the UV-C fraction is virtually completely absorbed by the atmosphere. This is why microorganisms did not have the opportunity to develop proper mechanisms of resistance against UV-C. Therefore, the part of UV radiation most effective in destroying these organisms is UV-C with a peak of inactivation at 254 nm for bacteria.
Since these short UVC wavelengths are entirely absorbed the atmosphere and do not reach the earth’s surface, these wavelengths are only available to us through artificial sources, such as UVC LEDs or mercury lamps. The intensity from point sources like UVC LEDs falls off as 1 over distance squared, and once it gets past the scattering length, it falls off exponentially. This means that 1) the further away the UVC source from a human, the lesser dose they are exposed to, and 2) the absorption length of UVC radiation in human skin is extremely short so that almost no UVC radiation can reach the living cells in the skin; all the absorption occurs in the dead cell layers.
In short, the shorter UVC wavelengths are typically absorbed in atmosphere, and thus are thought to have less long-term damaging effects on human tissue. However, in rare instances of prolonged direct exposure to UVC light, temporary eye and skin damage have been exhibited, such as cornea injury (sometimes referred to as “welder’s eye”) although this generally heals after a couple of days. Therefore, safety recommendations with UVC LEDs include protecting skin (in particular open wounds) and, most importantly, the eyes from UVC radiation.
The EU health agency’s safety guidelines on the use of UVC sources can be found at: https://ec.europa.eu/health/ph_risk/ committees/04_sccp/docs /sccp_o_031b.pdf.
In particular, the study concludes:
“In any case, UVC is strongly attenuated by chromophores in the upper epidermis (Young, 1997) and UVC-induced DNA damage in the dividing basal layer of human epidermis is not readily detected (Campbell et al, 1993; Chadwick et al, 1995) which may explain why the dose response curve for UVC erythema in human skin is very much less steep than for UVB (Diffey and Farr, 1991). It is unlikely that UVC from artificial sources presents an acute or long-term hazard to human skin. However, UVC is likely to cause acute photokeratitis… UVC exposure is unlikely to cause acute or long-term damage to the skin but can cause severe acute damage to the eye and should not be permitted at all from any tanning device.” The same study found the minimum health and safety requirements regarding the exposure of workers to risks arising from artificial optical radiation (2006/25/EC) – albeit for all UV bands combined: “Exposure limit value for UV (180-400nm) is 30 J/m2 (= daily value of 8h)”
The damage to microorganisms caused by UV radiation occurs directly on DNA. UV irradiation of the DNA molecule causes thymine bases to form dimers. Thus, the enzymes responsible for unwinding and copying the DNA during replication are not able to function anymore. This renders the microorganism unable to reproduce and cause an infection. Most natural UV light is generated by the sun with about ten percent of sunlight being UV and only about three to four percent penetrating the atmosphere to reach the ground. Of the UV radiation that reaches the earth, 95 percent is UVA and five percent is UVB. No measurable UVC from the sun reaches the earth’s surface. Because of the spectral sensitivity of DNA, this is why microorganisms did not have the opportunity to develop proper mechanisms of resistance against UV-C. Therefore, the part of UV radiation most effective in destroying these organisms is UV-C with a peak of inactivation at 254 nm for bacteria. Only the UVC region demonstrates significant germicidal properties.
It is widely accepted that it is not necessary to kill pathogens with UV light, but rather apply enough UV light to prevent the organism from replicating. The UV doses required to prevent replication are orders of magnitude lower than required to kill, making the cost of UV treatment to prevent infection commercially viable.
Yes. Germicidal UV radiation is already used in hospitals to disinfect contaminated rooms and surfaces. UV systems are also used to disinfect drinking water in Los Angeles, and New York. The first full-scale UV disinfection system for water treatment was used in Marseilles, France in 1910. There is also a fairly robust consumer market- such as disinfectants for sleep apnea machines, baby bottles, aquariums, air purification, and cell phones. Please not that these devices have not been approved by the FDA so far, including UVsanitizer.us devices.
The scare over the Measles virus, one of the most contagious diseases known to man, is a good case-in-point. Nearly a century ago, Harvard University sanitary engineer, William F. Wells, discovered that germicidal ultraviolet energy killed airborne microorganisms, including Measles. In the 1940s, Wells installed UV-C in suburban Philadelphia day schools to combat the spread of measles and compared infection rates. The schools without germicidal UV-C experienced a 53.6% infection rate, while the schools with the germicidal wavelength saw just 13.3%. Around the same time, in 1936, Dr. Deryl Hart experimented with germicidal UV-C to disinfect an operating room at Duke University Hospital. He reported an 11.38% reduction in the rate of postoperative infection rates. Throughout the next few decades, UV-C was applied in schools and hospitals across the country, proving its ability to inactivate microorganisms and bacteria. Compared to germicidal fixtures used in these studies, newer fixtures are available today that provide greater UV-C output and coverage, are less costly, use less power, and are less expensive.
UVsanitizer is tested and proven to emit a germicidal wavelength of 270-280nm.
UVsanitizer has been tested on certified American Ultraviolet® UVC dosimeter cards. Click here to see UVsanitizer emits a germicidal UVC wavelength when held 3-5cm away from an object for up to 30 seconds.
Please keep in mind with UVsanitizer or any other UVC device, you will never actually see the UV light that is killing germs. The purple indicator light you see is just the indication that UVC is being emitted. UV-C light is harmful to our eyes so do not face the device upward or point directly into eyes.
3-5cm from object or surface you wish to sanitize. We recommend 30 seconds. Please note that UVsanitizer works best on smooth surfaces. UV-C penetrates superficially and the light can’t get into nooks and crannies which include buttons or deep crevices. If a germ is encased within a food particle, for example, the UV light won’t be able to get at it.
Click here to see that UVsanitizer emits a germicidal UVC wavelength when held 3-5cm away from an object for up to 30 seconds.
Although it is unlikely that UVC from artificial sources presents an acute or long-term hazard to human skin, please DO NOT use UVsanitizer on skin. Rare instances of prolonged direct exposure to UVC light, temporary eye and skin damage has been exhibited, such as cornea injury (sometimes referred to as “welder’s eye”) although this generally heals after a couple of days. Therefore, safety recommendations with UVC LEDs include protecting skin (in particular open wounds) and, most importantly, the eyes from UVC radiation. Never point the UVsanitizer light at your eyes.
While you do not need to wear goggles, some might feel more comfortable wearing them if you are exposing many items over a period of time. As irradiation sources, UVC LEDs require some precautions to ensure safe usage. You should wear goggles if you think you might accidentally expose your eyes with the UV light. ANSI Z87 rated eyeglasses with wrap around lens to protect the side exposure is recommended.
No, UVC light is completely particle-free after use. This means it is safe to touch items, eat off items, or wear items immediately after cleaning.
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Absolutely! UVsanitizer can handle any volume of order, whether you are buying for yourself, as a gift, for your family, or a large business – we can fulfill any order. If you do have any orders larger than 50, please contact us for special pricing!