UV Sanitisers

What a UV sanitiser is

A UV sanitiser shines ultraviolet light on a phone, as a way to deal with germs without liquid. They come in two main forms: a closed box that the phone goes inside, and a handheld wand that you pass over it. They appeal to people who handle a phone all day in shops, offices, hospitals and on public transport, and to anyone wary of putting liquid near a phone.

Neither Apple's nor Samsung's cleaning advice mentions UV. Their advice is a soft cloth for cleaning and, to disinfect, a 70 percent isopropyl alcohol wipe or cloth, gently on the outside of the phone. A UV sanitiser is an extra to that, not a replacement.

What ultraviolet light can and cannot do

What is known about ultraviolet light on surfaces comes from health regulators. The US Food and Drug Administration explains that ultraviolet-C light can only act on a surface it reaches directly. Anything in shadow, or covered by dust or grime, may not be disinfected. On a phone that means the edges, the ports, the gap between phone and case, and anywhere greasy.

Ultraviolet light also does not remove dirt. It does nothing for fingerprints, fluff in the port or grit under a case. Cleaning removes dirt; disinfecting deals with germs on a surface that is already clean.

Boxes or wands: the safety point

The FDA warns that direct ultraviolet-C light on skin and eyes can cause painful eye injuries and burn-like skin reactions, and it has told people not to use some handheld UV wands that give off unsafe levels of it. That is the main reason to choose a closed box over a wand: in a box the light stays inside. A box that switches its lamp off when the lid opens is the safer kind.

How to use one

1. Clean the phone first with a soft cloth, because ultraviolet light does not reach through grease or dust. See screen sprays and cloths.
2. Take the case off, so the light reaches the whole phone.
3. If the box lights only one side, run it with the phone face up, then face down.
4. Never look at the lamp or shine it on skin.

The guide to cleaning your phone safely sets out the makers' advice in full.

Questions people ask about UV sanitisers

Does a UV sanitiser replace cleaning?

No. It does not remove dirt, and it cannot reach shaded or dirty surfaces. Clean the phone first.

Can I put earbuds in one?

The same limits apply: only surfaces the light reaches directly. Clean earbuds by hand first, with a dry soft brush from port and earbud brushes.

More to look at

• All cleaning and care
• Screen sprays and cloths
• Phone cleaning kits
• Port and earbud brushes
• Dust plugs
• Guide: How to clean your phone safely