As Brits try to cut energy bills amid the cost-of-living crisis, many have turned to electric blankets to help them keep warm on a budget.

With many available from online marketplaces such as Amazon, eBay, AliExpress and Wish, an investigation has revealed some shouldn’t be sold legally in the UK, while others are inefficient when it comes to keeping you warm.

Shock horror

Nine out of 11 electric blankets, throws and shawls tested by Which? were found to be badly made. In one electric blanket wires were simply “twisted together and covered in sealant” to “hide a second-rate connection”, the consumer champion said.

It came with a European two-pin plug and a “cheap and nasty” UK adapter, with the pins much too close to the edge of the plug, which presents an electric shock risk.

Another bought for £18 also had a “dodgy and dangerous” UK three-pin plug adapter that meant users could get an electric shock.

Meanwhile, an electric blanket bought for £22 had wires which could be “easily pulled out”, which was a “clear sign of the poor build quality”, Which? said.

Overall, eight of the 11 electric blankets tested were poorly made, with many standard safety warnings missing and, in some cases, half of the instructions not given in English. Nine of the products Which? assessed failed to include either a UKCA mark or a CE mark, which indicate compliance with safety standards.

Elsewhere, it also found some of the products were “incredibly inefficient”. A Cenlang heated shawl costing £12.99 on Amazon Marketplace, and an electric heated blanket poncho on eBay for £15.99, had only 5% of the total surface area of the respective products heated, the size of a sheet of A5 paper.

Only two electric blankets out of 11 passed all of Which?’s tests. One on Amazon Marketplace, a 1Above double size heated blanket, bought for £27, and another on eBay, an electric heated throw bought for £22.

Tips to help you avoid dangerous electrical blankets

Which? said it is hard to tell if a product is electrically unsafe just from looking at it. If there are problems, they’ll often be hidden away inside but there are some tell-tale signs to look for:

1) Packaging

This should show information about the manufacturer, the importer, how to dispose of the products and a UKCA or CE mark. The two products that passed all of Which?’s tests were professionally packed in carry cases with handles, with both displaying all of the required information. The rest came in plastic bags with no other information.

2) Instructions

Instructions should be in English and explain how to use and how to maintain the blankets. They should contain safety instructions and any relevant warnings, for example, to not use the blankets when wet, guidance on washing them and the warning sign showing that electric blankets should not be used by very young children.

Products failing Which?’s tests came with no instructions or instructions not in English with all standard safety warnings missing.

3) Markings

Look for the UKCA or CE mark on the packaging and the product itself as well as the WEEE disposal logo. And again look for a safety warning and washing instruction labels on the product. If these are missing, the product cannot be legally sold in the UK and could be substandard in other ways, too.

4) Plugs

The plug should be a UK three pin plug. If the product comes with any other kind of plug and an adaptor, the alarm bells should start to ring. It is also worth noting that the markings mentioned above are also required for all plugs. All three blankets Which? tested that came with the wrong plug and an adaptor posed an electric shock risk to anybody using them.

5) Loose wires

Look for wires that do not seem to be safely secured. If anything looks wrong or if you can see the insulation on the wires themselves poking out of the plug or the cable, stop using your electric blanket.

Sue Davies, Which? head of consumer protection policy, said: “Electric blankets have surged in popularity as people look to save money during the cost-of-living crisis, but our latest research shows that buying these products cheaply on online marketplaces can put your safety at risk.

“The Government must urgently act to give online marketplaces greater legal responsibility for unsafe and illegal products sold on their sites so that consumers are no longer put at unnecessary risk of harm.”