A Which? investigation has led to 10 dangerous carbon monoxide alarms being removed from sale by Amazon and Ebay.
Our independent tests revealed that a group of cheap and imported carbon monoxide alarms that are widely available online failed to detect the killer gas in more than a third of our carbon monoxide gas tests.
All of the unreliable and dangerous alarms were claimed to meet the EU safety standard (EN 50291) for carbon monoxide alarms. But the results of our lab tests lead us to believe that these claims are false.
In contrast, 13 other carbon monoxide alarms from leading brands passed every one of our 312 gas detection tests.
Dangerous carbon monoxide alarms to avoid
These three dangerous carbon monoxide alarms collectively failed 26 out of our 72 gas tests. They also come with potentially unsafe instructions advising owners to not install in the kitchen, where in most UK homes you’ll find a gas boiler.
ATZ Saviour Carbon Monoxide Alarm, £12.99
Failed to detect carbon monoxide in six gas tests.
Mudder Carbon Monoxide Alarm, £8.99
Failed to detect the killer gas in five gas tests.
Binwo Carbon Monoxide Alarm, £8.99
Failed to detect the killer gas in 15 gas tests.
Read more about Don’t Buy carbon monoxide alarms.
Dangerous instructions and lookalike carbon monoxide alarm brands
Following the three alarms failing our lab tests, we bought eight more identical alarms from Amazon, which sells dozens of lookalike brands that we’re equally concerned about.
Seven included the same dangerous installation advice, which could lead to the alarm being fitted too far away from the source of carbon monoxide to be able to detect the gas. Four had claims that they are ‘Calibrated per EN 50291’, the EU safety standard, but we believe that these claims are false.
Our search for the source of the dodgy alarms led us to a factory in China. We’ve seen documents stating that one alarm made there – which is identical in appearance to the models that failed our tests and was offered for sale to us – had passed the EU safety tests.
But on closer inspection, the claimed legitimacy becomes murkier. The documents show only four days between the start and end of testing, when it actually takes at least three months to pass the EU safety tests.
Amazon and Ebay respond
Amazon told us: ‘The products in question have been removed from sale while we conduct a review of them.’ Ebay told us that customer safety is its number one priority, that it’s working with the alarm sellers to ensure its customers are informed, and that it works with Trading Standards to ensure listings comply with the law.
The importers of the Binwo and Mudder alarms didn’t respond to our offer to comment. ATZ Essentials, the seller of the ATZ Saviour alarm, told us it’s removed the alarm from sale, it apologises for any inconvenience and has offered a refund for alarms bought through Amazon.
We’re pleased that 10 dangerous carbon monoxide detectors have been withdrawn from sale following our investigation, but many alarms seemingly indistinguishable from those that so badly failed our tests are still for sale on Amazon, Ebay and elsewhere. We think that all identical alarms should be withdrawn while UK stockists investigate the safety of the products they are selling. And we’re calling on Amazon and Ebay to contact every customer who has bought one of the three Don’t Buys to alert them to the dangers.
If you’re looking to buy a carbon monoxide alarm, aim to pay around £20, look for the Kitemark on the packaging and check out our carbon monoxide alarm reviews before you buy.