Do UV Sanitizing Wands Really Work?

We've been writing a lot about the benefits of germicidal UV-C lighting in many applications , but not all UV products are created equal. Portable UV wands or handheld UV lights claim to clean everything from cell phones to airplane seat back trays. And while the technology is seemingly convenient, does it really work to kill germs?

UV Basics First, let's understand the basics of UV, or ultraviolet, lighting. You can also read a whole post about the basics here.

UV light is a type of naturally present electromagnetic radiation that is in sunlight and actually makes up approximately 10% of the total light generated by the sun. UV light is electromagnetic energy with wavelengths shorter than visible light but longer than x-rays. The wavelength of this light ranges from 10nm to 400nm and is classified into three sub-bands; UV-A, UV-B, and UV-C.

UV light with wavelengths less than 290nm are considered to have “germicidal” properties (they kill germs). Earth’s atmosphere absorbs ultramagnetic radiation with wavelengths less than 290nm, meaning that most of the UV-C and UV-B generated by the sun is blocked by our planet’s ozone.

Germicidal UV-C lighting can kill up to 99.9% of pathogens. How? It kills cells by damaging their DNA. Exposure to the electromagnetic radiation (light) at certain UV wavelengths modifies the genetic material of microorganisms and destroys their ability to reproduce. The UV energy triggers the formation of specific thymine or cystosine dimers in DNA and uracil dimers in RNA, which causes the inactivation of microbes by causing mutations and/or cell death as well as failure to reproduce. (source)

UVGI UVGI, or ultraviolet germicidal irradiation, is a method of disinfection that uses short wavelength ultraviolet light (UV-C) to inactivate or kill microorganisms and pathogens. Essentially, UVGI is the use of UV light with sufficiently short wavelengths to disinfect surfaces, air, and water. Read more about UVGI here.

Do UV Sanitizing Wands Really Work? There are several lamp types and fixture types available for UVGI, and we'll get into that more below, but we get asked frequently if UV wands, which are available widely on the internet (a search for "UV light wands" returns nearly nine million Google search results), can work to disinfect the same way these healthcare-grade fixtures and units do. The answer is usually no.

First of all, many of the wands are not sold by reputable manufacturers (there have been lawsuits because of false germ-killing claims), or even by manufacturers at all. If you're buying a product off of Amazon and expecting it to have the same germ-killing power as a clinically tested UV-C unit that requires training, you're going to be disappointed. Make sure you request a Clinical Validation Study for any UV disinfection system manufacturer you are considering. Without a validation study, how can a manufacturer claim how effective a product is in regards to disinfection?

Not a One Size Fits All Solution The commercial fixtures and mobile units that provide germicidal UV-C light and do actually kill 99.9% of pathogens when used properly are, as we said, clinically tested so these claims are proven. There have also been independent studies by the CDC and others verifying efficacy. Even if the wand you want to purchase happens to be clinically tested, wands don't and can't account for your specific space; they're one size fits all "solutions." The problem is that not every space is the same size, not every space has the same materials in it, etc. While a wand may disinfect your phone sufficiently (it's true, they can often do this well), it can't just automatically disinfect an entire operating room in a hospital too. The units and fixtures that are effective are selected and installed with your specific disinfection needs in mind and your space's size in mind so that the right level and power of UV lighting can be applied. For instance, a larger room may need five fixtures installed. One wand isn't going to cut it, even if you meticulously use it throughout that space.

Another important factor when using germicidal UV-C lighting is the intensity of the light and how far the light is from the surface or material you're trying to disinfect. With a wand, there are too many human errors that can easily occur to ensure its effectiveness. What if one user holds it one foot from the surface and another holds it three inches from that same surface? Moreover, even if you're told by the wand directions to hold it one foot from whatever you're disinfecting, are you actually going to measure one foot each time you go to disinfect? Are you going to hold that wand steady exactly at one foot the whole disinfection cycle? This is part of what we mean by human error.

When a fixture is installed or the appropriate mobile unit is selected from a reputable source, you and your staff are trained to use it, first of all, but also that fixture, for example, remains in the same spot at the correct distance from whatever you're disinfecting and disinfects in 360 degrees. This article shows how a hospital's use of UV disinfection lighting isn't comparable to a wand because of size.

This study on wands really sums it up:

"'UV light has some utility,' notes Eleanor Fish, a microbiologist and senior research scientist at the Toronto General Research Institute in Ontario. But 'the reality is that with something like a UV wand, it’s the distance, it’s the intensity of the light, it’s the surface that you’re waving this wand over. Is it marble? Is it glass? Is it wood? … And how often is it tested to make sure it’s working?'"

Training. Safety, and Controls We can't underestimate the importance of training, and reputable UV disinfection lighting will require at least some training before operation . Did you know that different spaces and surfaces require precise and differing amounts of time to effectively disinfect? Again, what if one person is holding a wand up to a surface for ten seconds and another person is doing the same for three minutes. Training not only eliminates this problem, but so does the automatic controls and disinfection cycles included with reputable fixtures and units. Good germicidal UV-C lighting comes with preset timed cycles, auto on/off controls, sensors, etc.

Without these auto on/off controls that turn the lights off if someone enters the space when a disinfection cycle is occurring, can we really trust that people will remain safe? Wands do tend to come with some safety controls, but ultimately they require a person to be in the space operating the wand exposing themselves to UV. That's not true of all UV disinfection products. We wrote more on safely using UV products here.

Conclusion: There are Better Convenient Options Available If you're in the market for a convenient and portable UV disinfection solution, we would recommend mobile UVGI units over wands for all of the reasons above. These units can be easily moved from room to room, but still provide the 360 degree proven germicidal effects of an installed fixture. Take a look at the image below for an example, and get in touch with us for a custom UV disinfection lighting solution.

Puro Lighting

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