IPhone owners are being warned not buy budget chargers which have the potential to deliver lethal electric shocks.

The warning comes after charity Electrical Safety First, with the support of Apple, conducted a series of safety tests on 50 counterfeit and lookalike iPhone chargers, in the UK and found (98%) had the potential to deliver lethal electric shock and/or cause a fire.

The chargers were sourced from a variety of online marketplaces and independent discount stores and stalls.

Martyn Allen, technical director at Electrical Safety First, said: “It is extremely concerning that 49 out of 50 UK chargers we tested failed basic safety checks.

“This report shows that anyone purchasing an iPhone charger from an online marketplace or at an independent discount store is taking a serious risk with their safety.

“The majority of chargers we tested had the potential to deliver a lethal electrical shock or cause a fire. We’re urging people to take care when buying a charger and recommend buying directly from trusted retailers only. When you buy a fake, at best you could damage your phone but at worst you could be putting your life, your family and your home at risk.”

Of those tested, all but one failed one or more of the tests and more than one in three chargers failed every part of the safety screening.

Overall, two in three (68%) of the chargers tested carried a severe risk of electric shock due to lack of insulation and poor quality internal components.

But, how can you tell when the charger on offer is the real deal?

1. Check for safety markings on the plug

Look for missing markings (like the CE mark) or spelling errors. These are the easiest ways to spot a counterfeit – but beware as fake products are becoming more sophisticated.

2. Check the plug pins

The pins on a genuine charger are uniform and have a matt finish. On a counterfeit chargers the finish is usually glossy with imperfections.

Another easy check is to flick the largest pin and listen to the noise it makes. A genuine plug will sound and feel solid, while a counterfeit will make a plastic noise and feel hollow.

3. Check the USB port is in the correct place

The USB ports on a counterfeit charger might be upside down or in a different place. A genuine charger will also have a serial number at the back of the USB port.

4. Check the weight

As a counterfeit contains few, if any, of the higher quality components, the are usually significantly lighter then genuine should weigh at least 40g.

For advice and tips on spotting a fake charger, visit electricalsafetyfirst.org.uk/fakechargers or search #SpotTheFake on social media.