Can You Clean Your Smartphone Off Bacteria and Viruses with a $23 UV Disinfection Box?

This morning, as I browsed the web looking for products or other news, I found out that Banggood was selling a $23 UV sterilizer disinfection box that can clean & disinfect your smartphone, and other small items like surgical masks, using 3-minute of exposure to ultraviolet light.

I suppose it showed up in the new arrival feed because of the COVID-19 pandemic, and a relevant entry on Wikipedia states that UV light can kill bacteria and viruses since it destroys DNA and RMA. It works on humans too, and when I say work, it means humans should not subject themselves to strong UV light since it will damage their DNA too.

An article on Digital Trends mentions that while there aren’t many studies about the UV light effect on SARS-CoV-2, the virus causing COVID-19, it’s been shown to be effective against the similar SARS and MERS viruses, and hospitals are using robots zapping UV light to disinfect hospital rooms while face masks are being cleaned with UV treatment to allow reuse in this time of shortage.

UV Light Disinfection Box Coronavirus

Some basic specifications:

  • Lights
    • Wavelength – 254nm
    • Lamps – 2x 2W
    • Lamp life: 20000h
  • Disinfection time –  3 minutes with LED indicator for status
  • Input voltage: 5V 1A
  • Dimensions
    • External – 210 x 116 x H41mm
    • Internal – 200 x 100 x 22mm
  • Weight: 264g
  • Material: ABS

UV Light Disinfection BoxIn order to use the box, connect it to power and the LED should turn on. Insert your phone, face masks, or other small items you’d like to disinfect, close the lid, and press the button. The LED will be flashing blue during disinfection, and three minutes later it should be done, and the LED will turn orange. You can open the box and get back your item. 99.99% of bacteria should have been killed, and it’s also said to work on viruses. It’s not a clinically approved device, so who knows how efficiently it actually works.

For safety reasons, the box is hermetic in order to prevent UV light from leaking, and the UV lamp will turn off automatically when the lid is opened which may not be a bad idea since some people may decide to disinfect their hands that way, and it’s not safe, although I am not sure how much damage can be done with two 2W UV lights… [Update: Apparently a lot see comment]

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adrien
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adrien

UV-C is very dangerous: 2W is a *lot* and will quickly damage eyes and skin within tens of a second if not less. I have a 9W UV-C lamp and as far as I’ve understood it ought to kill germs 20cm away within 50ms or less.

Ozone blocks UV-C and that’s why the ozone layer matters that much. Keep in mind that merely with the currently slightly thinner ozone layer rougly above australia, the rate of skin cancer has vastly increased, includong among dolphins!

UV-C is terribly dangerous.

JJJ
Guest
JJJ

UVC is absorbed by the atmosphere, not necessarily just ozone. Basically no UVC reaches the earth surface as a result. Skin cancer is caused by either UVA or UVB (still a hot topic in the literature as to which one is the culprit, or which is worse). UVC is more commonly found from artificial sources such as mercury lamps and welding arcs.

Edit: just to be clear, skin cancer is not caused by UVC from the sun, purely because it can’t actually get to the surface of the earth, not because it isn’t dangerous. I’m not up to date on my UVC, but it would almost certainly increase cancer risk as it is basically approaching ionising radiation energies.

gum
Guest

odd I read that some medical devices were made to use UV-C to avoid harm.. because it penetrate skin much less than other UV wlengths.

JJJ
Guest
JJJ

This will not irradiate the underside of your phone. Might even be worse than not using it if it makes people think that their phone is clean when it is not.

If the light source is a mercury bulb then it’s likely to be 2W with best case 30% UVC output, so less than 600mW per bulb. Still very dangerous though.

UV can also damage polymers with high dosages, and UVC is the highest energy type of UV. So it may damage plastic/cases on your phone or adhesive on the display. High intensity UV will also damage LCD displays (see resin 3D printing where they need to be replaced regularly), and that’s barely even using the much weaker UVA. Not sure of the exact rate of damage, but just ask anyone who has left plastic things out in the sun in Australia.

theguyk
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theguyk

I too thought about the non exposed side of the phone. The safest way with your phone is use it less and do not share. Also think about remote controls for tv, media players. Door knobs, handles, keyboards and mice. Light and plug switches also taps, cups.

JJJ
Guest
JJJ

Isopropanol at 75% should be more than enough for your phone. The only reason they don’t use this on masks is that it destroys the filter. Viricidal power of isopropyl or ethanol is not the problem with reusing masks.

theguyk
Guest
theguyk

Sadly how many self isolating people have that ready to hand?

Note i am in UK.

JJJ
Guest
JJJ

Basically any “wipes” you buy from the supermarket that aren’t “water only” have this or equivalent (granted they are being hoarded, but still). But yes, some countries do control technical alcohols quite tightly. 151 proof spirits is also equivalent to 75% ethanol, apparently that is quite easy to buy in the US (also apparently people drink that???)

Isopropanol is easy to buy here in Australia (or was until recently…). $30 AUD for 5L of 99% or so.

David Willmore
Guest
David Willmore

Technical alcohols and other solvents are readily available in the USA at any hardware store. Go to the paint section and you’ll find a nice selection. Your local pharmacy (chemist) will have 91% IPA. Any decent liquor store will have 197 proof EtOH–look for brands like Everclear.

One note with the EtOH from the hardware store, it will have a denaturing agent in it. Most likely an agent that can leave an incredibly bitter aftertaste if used on surfaces which may reach the mouth. (https://en.wikipedia.org/wiki/Denatonium)

Chemical supply stores are less common, but are readily patronized via mail order. Any solvent that’s not regulated are readily available there.

theguyk
Guest
theguyk

Is that what we in UK calls Meths.

” Methylated Spirits is commonly known as Meths, Denatured Alcohol or Ethanol (Ethyl Alcohol), it is a virgin alcohol mixed with a small quantity of Methanol to make it unfit for consumption, and dyed purple. “

Matt
Guest
Matt

Not exactly, while any additive that makes alcohol improper for human consumption is a denaturing agent, methylated spirits have methanol as a denaturing agent and are improper mostly due to the toxicity of methanol, while denatonium makes it improper by making it too bitter to drink, same objective different methods.

geokon
Guest

Just do note that if you get >75% alcohol, you do need to water it down to 75%. A bit counter intuitively higher concentrations are not as effective at disinfection.

https://en.wikipedia.org/wiki/Isopropyl_alcohol#Medical

Member

Just received 2 bottles of Ethanol fuel for “Ethanol Fireplaces” from Amazon.de (I’m in Germany), as my previous 3 liter one is near the end after 3 years of use. It’s not for medicinal use, but as long as you don’t apply it to open wounds or drink it, should be perfectly fine to sanitize things like phones and door knobs.

gum
Guest

stupid question, how do displays and platics react to UV-C ? since many materials are degraded by UV, you’d be happy to know what is the limit before destroying your phone

David Willmore
Guest
David Willmore

Unless these use a quartz enclosed gas discharge tube for the UV source, I highly doubt anything they claim. I’m not aware of any UV LED in that frequency range. I just purchased a replacement UV source for an air processing filter and it cost more than this whole system–and that’s without the HV source, etc. Producing UV and ozone for disenfection in reasonable quantities takes more than a couple of 395nm LEDs in a box.

Matt
Guest
Matt

Actually UV LEDs are available in wavelengths down to at least 255nm iirc, which is in the UV-C range and pretty close to one of the emission lines from low pressure Mercury vapour. You can even find some UV-c LEDs on digikey.
There are also scientific papers on the use of uvc LEDs for pathogen inactivation: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6145099/

Edit: just to be clear I’m not saying this box works, I’m just saying that technology-wise it’s possible.
It’s also perfectly possible that the box is not irradiating at low enough wavelengths or that it’s not powerful enough, thought longer irradiation times could at least partially makeup for it.

David Willmore
Guest
David Willmore

Okay, let me clarify. I know that LEDs with emissions at pretty much any wavelength from deep UV to deep IR are available and have been for decades–IIRC, there was a place in Australia that made them–they are *horribly* inefficient. They’re good for lab uses if you need some specific known wavelength that you can’t get a laser for. But they’re so horribly inefficient that they’re not good for any kind of illumination. You can find simiconductors with the right band gap if you search hard enough, but getting high efficiency out of them is a different matter. The current GaN technology doesn’t scale to that short of wavelengths with any efficiency–and shouldn’t given the physics of the materials in question.

The efficienty figures in that paper are very low–and optimistic at best. The articles they link to seem to be all 404, so that doesn’t inspire confidence in their quality. Honestly, that paper looks more like a literature survey by a poor AI than by something a knowledgable human might have written.

What’s the chance that this $23 box uses some super amazing new 280nm technology? Honestly, you’d be better off with a little box, a fan, and an ozone source. That would cover more of the suface of an enclosed device and be way easier to produce.

Matt
Guest
Matt

Yeah I get it, hence the clarification about it possibly not being powerful enough.

I got tired after going through about 10 references, none were 404 most were behind some paywall, and as for the article itself it is very much par for the course and I fail to see how it looks like a literature survey by a poor IA, especially given the very much reproducible description of their experiment (except for saying some things were carried at room temperature and leaving me to guess how hot their lab was when they carried the experiment).

I suspect disinfecting your phone with ozone might eat through gaskets and plastic pieces in it, so please don’t.

Willy
Guest
Willy

I suspect it is indeed using a tiny 254nm UV tube, they exist in various sizes. These heat a lot and will damage most plastics. I’ve used them to erase EPROMs and expose PCBs. They also slightly ionize air and produce ozone which causes this nice slightly bitter smell.

Such wavelengths are really dangerous. During a summer 25 years ago we were infested by fleas due to cat and dog bringing them inside the house. After being really fed up with not being able to put a foot on the floor in my bedroom without it being covered with black dots I decided to turn on my UV lamp (four 21W tubes) for one hour or so wide open in the room. A few hours later, no more trouble, all fleas were apparently dead.

There are much less dangerous UV LEDs available at 365nm. They still make lots of white plastics glow, will itch your eyes a little bit but not as much as the 254nm tubes. I’ve though about using them to make cleaning devices to clean up COVID-19 but I abandoned the idea as this would further reinforce people’s paranoia, and I’m pretty sure others will do it anyway.

theguyuk
Guest
theguyuk

Not just phones, how do average people even test these kill germs?

https://www.aliexpress.com/item/4000805875515.html?

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