Do Your Homework Before Buying a UV Disinfecting Gadget

It’s likely that in the past few weeks or months, you’ve come across an ad for a UV disinfecting gadget. It makes sense! There’s a novel coronavirus going around wreaking havoc! Your phones are filthy, your bags are filthy, your masks are full of your own face sweat and spit. Maybe, you ought to buy one of those UV wands, phone disinfectant cases, or hell, back this weird UV toilet brush on Kickstarter.

The latest of these UV gadgets to hit the news cycle is Samsung’s UV Sterilizer with Wireless Charging. In its global press release, Samsung writes, “In today’s world, personal hygiene is more important than ever, and to help combat the spread of bacteria and germs, we’re introducing a new UV Sterilizer with Wireless Charging.” The device itself claims to kill up to 99% of those nasty bacteria and germs, listing E. coli, Staphylococcus aureus, and Candida albicans as certified by Intertek and SGS, two independent product testing labs. This thing also doubles as a wireless charger, meaning you could simultaneously recharge and sterilise any gadget or item that fits in the box.

This sounds great! A history of exploding and cracked smartphones aside, Samsung has a pretty good reputation for electronics. Plus, independent testing and certification sound legit. This is a prime example of a product from a brand you’d probably trust that, actually, you should probably think twice before buying right now.

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It’s not that UV disinfection is a hoax. There’s a reason it’s used in hospitals to disinfect PPE, as well as water supplies. It’s just that there’s more to it than saying something is killing germs with the help of ultraviolet light. For starters, when you refer to something as being capable of UV disinfection, that’s UVC light, which has a wavelength of 100-280 nanometres. The type you find in the sun’s rays or tanning beds is UVA or UVB light. According to the International Ultraviolet Association (IUVA), UVC light has been used for over 40 years as a method of disinfecting water, wastewater, air, pharmaceutical products, and surfaces.

So why the fuss about UV gadgets popping up in your social media, or perhaps even your inbox? Well, even though UVC light works as a disinfectant, it doesn’t mean the products you can buy right now were built with effectiveness and human safety in mind.

“If done correctly, UV disinfection has been really effective for about 100 years,” Jim Malley, professor of civil and environmental engineering at the University of New Hampshire, told Gizmodo over the phone. Malley is not only the founding president of the IUVA, but he also has over 30 years of experience in using UV, as well as other chemical and physical methods, as a disinfectant. “The dilemma, and the big thing here, is ‘if done correctly.’”

According to Malley, the consumer market for consumer UV gadgets is like the Wild West. Not only is there no consistent regulatory oversight, but there’s also no universal seal of approval that makes it easy for consumers to understand that they’re buying something that’s safe to use. For example, in the wearables space, you at least have things like FDA clearance and the CE Mark to indicate a product is unlikely to cause you any harm. “Because it’s an unregulated market, knowingly or unknowingly, companies are putting some absurd products out there,” Malley says.

“The safety and efficacy of many UV light devices sold to the public are not routinely reviewed, so these should be used with caution,” echoes the Penn Medicine FAQ on the novel coronavirus.

Take a UV wand, for example. If you search Amazon for “UV wand sanitiser” you get at least 71 results back. However, these devices unnecessarily expose your skin to UVC, which is actually quite dangerous for both your eyes and skin. Waving one of these wands willy nilly through your house might leave you — or perhaps a child or pet — with unintentional skin or eye damage. The same holds true for UV lamps, or if you want to play it safe, any product that doesn’t fully contain UVC light. On its site of covid-19 Mythbusters, the World Health Organisation specifically says UV lamps “should not be used to disinfect hands or other areas of your skin.”

Malley also notes that the effectiveness of these types of wands decreases with distance. So unless you’re using one of these gadgets up close and methodically, you’re likely not doing much.

Likewise, UV light only disinfects the areas the light can touch. Many UV phone disinfectant gadgets, Malley says, are often constructed poorly. “UV is a line of sight technology,” he explained. “If anything is shadowed, it’s not going to get any disinfection.” So if a box only has UV lights on one side, or isn’t made of reflective materials, it’s possible the top or bottom of your phone is still crawling with germs. This tracks with the fine print on Samsung’s press release, in which a footnote reads that “areas of the product that are not exposed to the UV light will not be disinfected.”

The other issue at hand is covid-19 itself. You can bet these UV gadget makers are capitalising — possibly with good intent — on the current moment now that the public is taking disinfecting more seriously. However, there’s a lack of wide-scale, peer-reviewed research into whether widely available, consumer-grade UV gadgets are effective against covid-19. Malley says given what scientists know about other virus families and SARS-CoV-2, the novel coronavirus that results in covid-19, there’s been no evidence so far that the pathogen would be resistant to UVC disinfection. However, it’s common sense that if a product is claiming it can definitively kill the novel coronavirus without the research or testing to back it up, it’s probably too good to be true.

That’s not to say there are absolutely no companies out there doing things the right way. It’s just likely that their products will set you back several hundred or even thousands of dollars.

But even if you found a well-designed, validated, and affordable UV disinfectant gadget, it wouldn’t mean you could give up hand washing, social distancing, or wearing masks. That, Malley says, is a classic example of a product giving someone a false sense of security.

“Most of the time, it’s not worth your effort,” Malley explains, adding that quick-drying disinfectant wipes that are at least 60% alcohol are a better option. “If UV is really something you need, you got to look at the old sayings. You’re gonna get what you pay for and you need to do some sort of due diligence.”

That means doing your homework. While the IUVA is working on a set of protocols that would codify a validation process, that’s not something that can happen overnight. Likewise, it will be a while before validation or certification centres are established for such a new product category. In the meantime, there are a few things consumers can do to make a more educated choice.

For starters, consumers can look to see whether the companies behind the products have properly invested in research and development. You can also investigate whether a gadget has been used by hospitals, or if the company itself is willing to send you the results of a validation study done by an independent, reputable lab. And if a product checks none of these boxes, perhaps it’s best to simply take it out of your cart.