The Lifx Clean LED uses HEV light to kill bacteria like staph, strep and salmonella. Later this year, it’ll be tested for antiviral efficacy, including efficacy against the virus that causes COVID-19.
We’ve seen plenty of smart lights you can control with your voice, as well as smart lights that sync with your music, with your TV screen, or with your home security system. But how about a smart light bulb that promises to disinfect your phone, or even your bathroom?
That’s the latest pitch from Lifx, a major smart lighting brand based in Australia. The company tells CNET it’s preparing to release a new Lifx Clean LED in North America later this year, billing it as “the world’s first antibacterial, germicidal smart light that works as a disinfectant.”
The $70 bulb looks and functions just like one of the company’s original, flat-topped Wi-Fi smart bulbs, complete with all of the colors, features and voice controls users are already accustomed to. What’s new are additional diodes that can be triggered to emit high-energy violet light. That HEV light — which Lifx claims is certified safe for people, pets and plants — is capable of killing certain kinds of germs and bacteria, including pathogens like E. coli and staphylococcus aureus.
It’s an approach that’s been used before in medical environments and in things like specialty light fixtures for the kitchen. Now, Lifx wants to bring the idea into the smart home.
“We’d been considering using germicidal light in a smart bulb before March, but the onset of COVID bubbled it up to the surface fast,” said Lifx CEO David McLauchlan. “When supermarkets the world over started to run out of cleaning products, when liquor companies started making hand sanitizer and clothing companies started making face masks, we started thinking about ways we could help.”
How it works
The Lifx Clean LED only activates its HEV diodes when you turn them on. The rest of the time, it’ll put out regular light in any color or any shade of white you like.
When it isn’t zapping bacterium, the Lifx Clean LED can put out light in any color or any shade of white you like.
“It’s a Lifx A19 (white and color), but with this extra thing, rather than just a weird blue light,” explains Lifx Global Marketing Director Sam Moore.
With a built-in Wi-Fi radio, you can connect the bulb directly with your home network — from there, you can control the bulb and schedule lighting changes from the Lifx app on your Android or iOS device. You can also connect the bulb with a third-party smart home system like SmartThings and Apple HomeKit, or with a voice assistant like Alexa, Siri or Google Assistant.
Lifx sees the bulb as a good fit for a smart lighting schedule. Screw the bulb into a bathroom vanity, for instance, and you could program it to bathe the space in HEV light each night as you sleep, killing bacteria in the area around your shower, toilet and sink. You could similarly turn a desk lamp into a disinfecting station for your cell phone, keys and anything else you touch regularly throughout the day.
“In certain ranges our lights can outperform non-smart commercial competitors, with overnight disinfectant kill rates of up to 99.99% for certain bacteria,” McLauchlan says.
What kinds of bacteria?
That’s a good question, and currently the subject of lab-based efficacy testing conducted by the Department of Chemistry and Biotechnology at Australia’s Swinburne University of Technology. Lifx tells CNET that it wants to be careful not to overstate any germ-killing claims, and that it’s still running various trials to determine the specific bacteria-killing efficacy at specific distances and for specific periods of time.
“We needed to get certain efficacy in testing to be a viable product,” Moore tells CNET. “We have that. We’re excited.”
For now, Lifx tells CNET that the tests have established efficacy against E.coli and staphylococcus aureus. The company adds that it will be publishing detailed bacteria kill rates closer to launch next quarter, and that additional tests are underway and in the works.
Is it safe?
The Lifx Clean LED arrives amid a global pandemic, and interest in germicidal light is surging. Much of that interest has centered on ultraviolet UVC light, which functions as a natural and long-established antiviral disinfectant, but comes with significant safety concerns, since even a few moments of direct exposure can be hazardous to the eyes and skin.
When HEV mode is activated, the Lifx Clean LED will emit soft, bluish light capable of killing bacteria.
The HEV light used by the Lifx Clean LED is different, and less intense. Shining at a wavelength of 405 nanometers, it sits comfortably above the 100-280 nanometer range of invisible UV light, with visible light that looks bluish in appearance.
That doesn’t mean that HEV light is harmless. Concerns about the effect of HEV or blue light on our eyes and sleep patterns have been around for years, specifically with regards to the blue light emitted by TV and phone screens. Other scientific studies note the antibacterial properties of HEV light and its common dermatological applications as a treatment for conditions like acne — but they also suggest that blue-violet light at high doses could be hazardous to human skin.
To that end, Lifx says that the bulb was tested to meet the IEC 62471 photobiological safety standard at an accredited Underwriters Laboratories facility in China. That, Lifx says, ensures that there’s no risk from exposure to the skin and eyes.
“IEC 62471 is now recognized in many countries as the key standard addressing photobiological safety issues related to lamps, lamp systems and other non-lamp sources of optical radiation,” reads UL guidance on LED safety published in 2015.
“IEC 62471 identifies the UV range from 100 to 400 nm,” adds Bahram Barzideh, UL Principal Engineer for LED Lighting Components. “The 405 nm wavelength is considered part of the visible light spectrum (400- 700 nm) and is not subject to actinic UV hazard exposure limits of IEC 62471.”
In other words, UL draws a line between UV light and HEV light when it comes to skin. The former is a clear hazard in the organization’s eyes, but the latter is not. Lifx agrees.
“Products that use UV light (under 400 nm) can be very effective in killing (or eliminating the reproducibility of) cells, but those wavelengths of light are not safe for unprotected human eyes or skin,” McLauchlan says. “However, light above 400nm is safe for humans, and specifically 405nm light has demonstrated consistent germicidal properties.”
Another one of the risks that IEC 62471 tests for is photoretinitis in the eyes, or blue light retinal injury. A photochemical reaction to visible light that typically falls between 400 and 500 nanometers, photoretinitis can cause blind spots in the retinas, and has been linked to macular degeneration.
Devices certified as risk-exempt under IEC 62471 “do not pose any photobiological hazard,” UL says. That’s the certification earned by the Lifx Clean LED, the company says.
What about COVID-19?
Tests for antiviral efficacy — including tests against SARS-CoV-2, the virus that causes COVID-19 — are up next for the Lifx Clean LED, but the company doesn’t expect to have those results until after the bulb hits store shelves sometime in the fourth quarter of 2020.
“No claim is currently being made that the product is effective in an antiviral capacity of any kind, including on SARS-CoV-2,” reads the company’s press release announcing the bulb. “Lifx will be publishing detailed bacteria kill rates closer to launch next quarter, and continues to conduct extensive testing on various microbes, which will include SARS-CoV-2 testing.”
I’ll certainly be eager to see that data once it’s available, but I wouldn’t hold out too much hope that this thing is a potential COVID-killer. While UV light is well documented to combat viruses like influenza and coronaviruses like the one that causes COVID-19, the little science that I’ve been able to dig up regarding potential antiviral applications for HEV light seems inconclusive at best. Time will tell, but the Lifx Clean COVID trial may amount to little more than a moonshot.
We’ll keep an eye on those tests as the bulb’s release draws near. Expect to hear more by the end of the year.
First published on Sept. 1, 2020 at 5:00 p.m. PT.