Which? found four alarms consistently failed to sound when gas was present
A Topolek GEHS007AW CO alarm, which was a bestseller on Amazon.
Dozens of potentially deadly carbon monoxide alarms have been removed from sale by Amazon and eBay after a Which? investigation found some of them would not have protected their buyers.
The consumer group tested four alarms that were on sale on both sites – including an Amazon bestseller – and found that they consistently failed to sound when the gas was present.
Which? said all four claimed to meet the British safety standard for detecting carbon monoxide.
Carbon monoxide poisoning causes about 50 deaths a year in England and Wales, and up to 4,000 incidents a year result in a hospital visit.
Which? has called on the Office for Product Safety and Standards to take a more active role in market surveillance to identify products that pose a potential safety risk.
It said one of the alarms – the Topolek GEHS007AW CO alarm (£14.99) – was listed as a bestseller on Amazon. It failed to detect the gas in more than 80% of tests.
Three other unbranded alarms that were made in China and sold through sellers on Amazon and eBay for under £10 also repeatedly failed to sound when there was carbon monoxide present.
Amazon and eBay have removed the alarms from sale and delisted another 50 lookalike alarms.