Amazon, eBay and Wish remove blood oxygen testing devices after Which? raises concerns

Amazon, eBay and Wish have removed a number of blood oxygen testing devices from sale after Which? found products that were not legally fit to be sold in the UK and, in some cases, falsely claimed to be NHS-approved.

The consumer champion found 11 out of 15 cheap pulse oximeters bought from online marketplaces for as little as 99p failed to comply with UK and EU law when it assessed them.

Pulse oximeters have become increasingly popular since the Covid-19 pandemic began. They measure oxygen levels in the blood which can drop to dangerously low levels without the patient noticing, in what is known as “silent hypoxia”. Pulse oximeters are being used by the NHS to assist vulnerable patients with home monitoring of Covid or post-Covid symptoms. Patients may be given a pulse oximeter by their GP.

The products that Which? analysed featured prominently in search listings, had lots of reviews and in some cases featured marketplace endorsement labels.

Which? found that one product being sold via the online marketplaces was missing its CE mark completely, while others had CE marks that failed to comply with Medicines and Healthcare products Regulatory Agency (MHRA) guidance on required markings for a medical device. Some falsely claimed to be NHS-approved or used the NHS wording or logo to look more legitimate. This could potentially be a breach of consumer protection law.

A Department of Health and Social Care spokesperson told Which?: “The NHS does not approve or endorse any medical devices, including oximeters.”

When Which? notified the marketplaces about the incorrect certification on the products it found, they took them down – although five devices had already disappeared from sale before the consumer champion contacted the marketplaces.

Since the initial investigation, Which? found more ‘NHS-approved’ pulse oximeters being sold on Amazon and eBay. Amazon even sent marketing emails to Which?’s researchers, promoting ‘NHS-approved’ pulse oximeters.  This demonstrates that the reactive approach from marketplaces is not dealing with the overall problem.

All of the pulse oximeters Which? tested passed its accuracy tests without any major issues, so they were able to measure the blood oxygen saturation of each of Which?’s panel with an acceptable error margin. However, buying from an unknown seller could come with risks, as the high number of uncertified models shows. It can be a lottery for consumers to know what they are getting and other snapshot tests Which? has done, such as digital thermometers, have uncovered products that can give inaccurate readings.

The lack of CE marking or the presence of a non-compliant CE mark on most of them could call into question the safety, quality and accuracy of these pulse oximeters as they may not be manufactured to the required standards or conform to the requirements of the medical device legislation.

Which? believes the government needs to do more to increase checks on products being sold online by bringing in tougher laws and regulations to make online marketplaces legally responsible for ensuring the safety of products offered through their sites. It is not good enough for online marketplaces to take down products reactively when they are flagged by Which?.

Which? is sharing its findings with the MHRA and Office for Product Safety and Standards (OPSS). Later this year the OPSS will be providing an update on its UK product safety review and this provides the perfect opportunity to give online marketplaces greater responsibility for vetting products sold on their sites.

The UK has some of the strongest safety standards in the world but these are undermined by products that do not adhere to standards and regulations and easily make their way onto marketplaces.

Natalie Hitchins, Which? Head of Home Products and Services, said:

“It is very concerning that our investigation found these medical devices for sale without the required safety markings or brazenly claiming to be approved by the NHS – and the biggest online marketplaces were not picking up on these red flags.

“Which? believes the government needs to do more to protect consumers from a lack of effective safeguards when they are shopping online by bringing in tougher regulations for online marketplaces.

“Consumers should be wary of cheap oximeters sold on online marketplaces.”

Notes to editors

  • In January 2022, Which? assessed whether pulse oximeters sold on online marketplaces had the required CE markings and information present to be legally sold in the UK.

Oximeters that failed the CE mark assessments:

Bee Smart Pulse Oximeter, £12.99, bought from Amazon

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 does not have a CE mark of any description on the device or box, so it should not be sold in the UK.

Kamrose Pulse Oximeter, £7.99, bought from Amazon

Another Amazon model that failed Which?’s 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 does not comply with UK/EU law.

Tanness Finger Pulse Oximeter, £5.99, bought from Amazon

The product and the box it came in both have (very small) non-compliant CE marks, but Which? was concerned not to see any information about the manufacturer or their counterpart in Europe or the UK. It was also missing the four-digit code required to meet EU regulations, showing it has been assessed by a Notified Body.

This pulse oximeter does not comply with UK/EU law.

UK Fingertip Pulse Oximeter, £0.99, bought from eBay

This cheap pulse oximeter was missing several pieces of information for a compliant CE mark. Which? was 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 does not have one.

Unbranded finger pulse oximeter, £4.66, bought from Wish

While this cheap pulse oximeter has a visible CE mark in the right location, it is missing the name and address of the manufacturer and fails to provide the name of an EU representative. There is also no four-digit code linking the product to the Notified Body that checked it.

Because of this, it does not have a compliant CE mark for a medical device and therefore cannot legally be sold in the UK.

M260 Nail Pulse oximeter, £5, bought from Wish

Which? is 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 cannot be legally sold in the UK.

Others that failed Which?’s CE mark tests but had already been removed by the marketplaces before Which? approached them:

  • OEM Pulse oximeter, bought from eBay

  • Unbranded fingertip pulse oximeter, bought from eBay

  • Unbranded pulse oximeters (x3), bought from Wish

Additional background

  • Ten out of the 15 models on test had CE marks that did not comply with the law, and one was missing a CE mark completely.

  • A CE mark is a requirement for many products sold in the EU and European Economic Area. If a product has a CE mark, it shows that the manufacturer has checked that it meets all relevant health, safety and environmental requirements and complies with EU law.

  • In the UK the CE mark is eventually going to be replaced with the UKCA (UK Conformity Assessed) mark, which will become mandatory in January 2023. Businesses are still currently able to use a legally confirming CE mark for products sold in the UK until the permanent switch in January next year – which is why Which? checked for it in its product tests.

  • The UKCA mark came into effect from January 2021, but CE and UKCA markings are both allowed until January 2023 to allow for businesses to adapt after leaving the EU.

  • Pulse oximeters are classed as a medical device and the CE mark that each one carries needs to tick several boxes. The box, manual or the device itself need to include the name and address of the manufacturer, the name and address of the EU/UK representative (if the manufacturer is not based in the UK) and a 4-digit number, identifying the independent 3rd party organisation which assessed the device.

  • Which? also tested the fifteen 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). Experts 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).

Rights of reply


An Amazon spokesperson said:

‘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 Which?:

‘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 Which?:

‘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.’


‘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.’

A Department of Health and Social Care spokesperson said:

‘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.

About Which?

Which? is the UK’s consumer champion, here to make life simpler, fairer and safer for everyone. Our research gets to the heart of consumer issues, our advice is impartial, and our rigorous product tests lead to expert recommendations. We’re the independent consumer voice that influences politicians and lawmakers, investigates, holds businesses to account and makes change happen. As an organisation we’re not for profit and all for making consumers more powerful.

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