Cheap pulse oximeters sold on online marketplaces including Amazon, Ebay and Wish have been removed after a Which? probe revealed they didn't have the required CE marks to be legally sold in the UK, and some also made false claims to be 'NHS approved'.
11 out of the 15 pulse oximeters bought from online marketplaces did not have the correct certification.
The products were either missing CE marks completely, or had CE marks that failed to comply with UK Medicines and Healthcare Regulatory Authority (MHRA) guidance on required markings for a medical device.
Our research also revealed products making unauthorised claims to be 'NHS approved' or using the NHS wording or logo to look more legitimate.
When we notified the marketplaces about our test findings, they took down the uncertified products. However, days later we received marketing emails from Amazon promoting pulse oximeters which claimed to be NHS approved, despite the Department of Health and Social Care (DHSC) telling us that no such products are endorsed by the NHS.
Pulse oximeters were a relatively niche medical product in pre-covid days, but have become increasingly popular as some GPs recommended having one at home to monitor covid or post-covid symptoms during the pandemic ().
While all the cheap options we tested fared ok in our accuracy tests, buying from an unknown seller is still risky, as without the proper certification you never really know what you're getting.
A CE mark is a requirement for many products sold in the EU and European Economic Area.
A valid CE mark indicates that the manufacturer has checked that the product meets relevant health, safety and environmental requirements and complies with EU law. In the UK it is eventually going to be replaced with the UKCA (UK Conformity Assessed) mark, which will become mandatory in January 2023.
Pulse oximeters are classed as a medical device and the CE mark that each one carries needs to come with a series of things either in the box, manual or on the device itself. These are:
It also means if anything does go wrong, it's easier to track down the manufacturer and sort it out.
The 15 pulse oximeters we tested did at least pass our accuracy tests without any major issues, so they were able to measure blood oxygen saturation with an acceptable error margin, but 10 out of the 15 models had CE marks that didn't comply with the law, and one was missing a CE mark completely.
A CE mark being missing or wrong doesn't always mean that your product will be unreliable or unsafe, but it is a warning sign that something could be wrong, and the product may not be manufactured to the required standards or conform to the requirements of MHRA medical device legislation.
Products need a CE mark or a UKCA mark to be legally sold in the UK too, so a product without either should not be on sale.
It's worrying that out of a relatively small selection of what's available on these marketplaces, so many weren't fit to be sold.
These are the models that were removed from sale after we flagged issues with them:
Not only is this pulse oximeter missing valid contact information for the manufacturer or details of a UK/EU representative, there's also no four-digit code to show that it has been assessed by a Notified Body - which is a requirement for medical devices in this country.
It also doesn't have a CE mark of any description on the device or box, so it shouldn't be sold in the UK.
Another Amazon model that failed our CE mark assessments. There were non-compliant CE marks on both the box and the device, but they were very small (less than 5mm) and there was no information about the manufacturer - or a four-digit code identifying the Notified Body which assessed the device.
This pulse oximeter doesn't comply with UK/EU law.
The product and the box it came in both have (very small) non-compliant CE marks, but we were concerned not to see any information about the manufacturer or their counterpart in Europe or the UK. It's also missing the four-digit code required to meet EU regulations, showing it has been assessed by a Notified Body.
This pulse oximeter doesn't comply with UK/EU law.
This cheap pulse oximeter was missing several pieces of information for a compliant CE mark. We were unable to find the name or address of the manufacturer, the name and address of an EU or UK representative, or a four-digit number to show it has been assessed by a Notified Body.
As pulse oximeters are classed as medical devices, it requires a compliant CE mark to be legally sold in the UK/EU - and it doesn't have one.
While this cheap pulse oximeter has a visible CE mark in the right location, it's missing the name and address of the manufacturer and fails to provide the name of an EU representative. There's also no four-digit code linking the product to the Notified Body that checked it.
Because of this, it doesn't have a compliant CE mark for a medical device and therefore can't legally be sold in the UK.
We're concerned about the complete lack of manufacturer info provided in the box of this pulse oximeter. It also fails to include a four digit code linking the product to the company that carried out CE mark checks on it, and there are no EU or UK representatives either.
Because of this, it can't be legally sold in the UK.
Some pulse oximeters that failed our CE mark tests were no longer on sale once we'd finished testing. These include:
It's very common for these types of products to disappear from sale and reappear a few days - or weeks - later, using a slightly different brand or title or perhaps a new image, so it's possible they have since been re-listed.
With so many unbranded, generically-named products that come and go regularly, it's very hard to determine which ones are likely to be legitimate, or even tell the difference between them.
Several of the models we originally ordered turned out to be very similar devices that had been listed with multiple different names and images - showing you can never be 100% sure what you're going to end up with.
When it comes to a device as crucial and potentially life-saving as this, is it really worth taking the risk?
If you spot a mention of the NHS, the familiar blue logo or a product claims to be 'NHS-approved' you might feel reassured the product is more legitimate, but don't be fooled - these claims are unauthorised and meaningless.
We spotted pulse oximeter listings from third-party sellers on Amazon and eBay (including several of the non-compliant devices we tested) which made claims to be 'NHS-approved' or included the NHS wording or logo in the listing, giving the impression the devices were endorsed by the NHS.
We queried this with the DHSC, which told us: 'The NHS does not approve or endorse any medical devices, including oximeters. The department strictly controls the NHS identity and takes unauthorised use or adaption of the NHS logo and the letters 'NHS' very seriously.
'Where issues around misuse of the NHS identity and brand are brought to our attention, we actively investigate and will not hesitate to take the necessary action if we find unauthorised use.'
It went on to confirm it would be looking into this issue. We also flagged our findings with Amazon and eBay, who said they would take the listings down.
Following our investigation, we notified the online marketplaces of the six non-compliant products that were still available, and of the issue of products claiming NHS approval, and they took the offending listings down.
An Amazon spokesperson told us:
'Safety is important to Amazon and we want customers to shop with confidence on our stores. We have proactive measures in place to prevent suspicious or non-compliant products from being listed and we monitor the products sold in our stores for product safety concerns.
When appropriate, we remove a product from the store, reach out to sellers, manufacturers, and government agencies for additional information, or take other actions.
If customers have concerns about an item they've purchased, we encourage them to contact our Customer Service directly so we can investigate and take appropriate action.'
On the issue of 'NHS-approved' listings, Amazon told us:
'We have removed the products you have flagged and asked for relevant supporting evidence from the sellers for their claims.'
An eBay spokesperson said:
'We have strict policies in place to regulate the sale of medical devices and have removed the single listing flagged by Which? that did not comply with these policies.
However, we are pleased that Which?'s investigation found that the vast majority of products purchased on eBay met the relevant standards for safety and performance.'
On the issue of 'NHS-approved' listings, eBay told us:
'These items breach our medical devices policy, which sets out that when listing medical device products on eBay, sellers must comply with labelling requirements that apply to the packaging and Instructions For Use (IFU). We have removed these items from the site.'
Wish told us:
'All of our merchants must comply with local laws whenever selling on our platform, as noted in Wish's Merchant Terms of Service and Wish Policies.
After learning that these two listings were in violation of UK legal standards, which is a violation of our terms and policies, we promptly removed the listings from the platform in accordance with local law.'
We tested fifteen cheap pulse oximeters bought from online marketplaces including Amazon, eBay and Wish to extracts from British Standard EN ISO 80601-2-61:2019 and 'Particular requirements for basic safety and essential performance of pulse oximeter equipment' (ISO 80601-2-61:2017, corrected version 2018-02).
We tested how accurate each product was at recording blood oxygen saturation at rest on a diverse panel of six healthy volunteers, with each test being repeated five times.
Each reading was compared to those taken by a reference pulse oximeter (a professional medical device that complies with the IEC 60601-1 when providing its specifications).
In addition, we assessed whether each product had the required CE markings and information present to be legally sold in the UK.