Which? raises alarm over ‘greenwashing’ risks as it finds hundreds of products using vague and unsubstantiated environmental claims
Which? is raising the alarm about the potential for widespread “greenwashing” as a groundbreaking study from the consumer champion finds many popular products risk falling foul of rules designed to crack down on bogus environmental claims.
Which? trawled through more than 20,000 online product listings using AI software trained to find green claims. Researchers then looked in more detail at 1,000 online product descriptions in a range of categories spanning food, cleaning, electronics, clothing and personal care items, across popular UK retailers including Argos, Next, Ocado and Tesco.
The study found that more than six in 10 (62%) products failed checks in relation to multiple principles of the Competition and Markets Authority’s Green Claims Code - suggesting systemic issues with how eco-friendly credentials are being communicated.
The CMA introduced the Green Claims Code in 2021 to combat greenwashing, protect consumers from being misled and to promote fair competition among businesses by ensuring that those making genuine environmental claims are able to benefit from them.
However, Which? found many products that could be falling short of at least one of the code’s five of six principles including: be truthful and accurate, be clear and unambiguous, only make fair and meaningful comparisons, consider the full life cycle of the product, and be substantiated.
The vast majority of products (84%) that made a green claim failed at least one check in the Which? assessment framework of 24 points, which it derived from five of the CMA’s code of six principles.
Cleaning products, electronics and accessories, and personal hygiene products had the highest proportion of products failing checks for multiple principles, according to the research. By contrast, sectors like fresh produce fared better - likely due to strict regulation of organic certifications.
One of the most problematic principles seemed to be that “claims must be clear and unambiguous”.
Nearly two-thirds (65%) of products assessed failed checks in relation to this principle, largely driven by the use of words such as ‘eco’, ‘sustainable’ or ‘environmentally friendly’ in the product description, without backing them up properly. An overwhelming majority (88%) of these product descriptions did not justify, explain or provide any context to the use of the word at all. Whether truthful or not - this would make it difficult for a customer to assess the accuracy of the claim based on this information.
Which? found that the product description for Grind House Blend Ground Coffee at Tesco stated that the coffee is ‘ethically sourced’ from ‘sustainable farms' but there was no other explanation to support these claims. According to the CMA guidance, such statements are more likely to be misleading.
Another product Which? believes had similar problems was a Hey Duggee bean bag soft toy from Argos, where the product information includes the vague term, “environmentally friendly,” to describe its filling without being clear what backs up that claim.
Another principle in the CMA’s code says ‘comparisons must be fair and meaningful’ but Which? found almost nine in 10 (86%) products risked falling short. A Chad Valley Wooden Puzzles set (taken from Argos) carried the claim that because it was made of wood it was ‘more kind to the environment’. However, without being clear what specific environmental aspects are being compared (e.g. carbon footprint, resource use etc) or what it is kinder than (e.g. plastic toys) Which? believes could also be seen as being misleading.
When Which? looked at food items, the description for a Charlie Bigham’s Lasagne on Ocado claimed to use ‘30% less cardboard’ but without stating if this is comparing a previous version of the same product or other lasagnes on the market. Which? believes this may also fail against the fair comparisons principle of the code for the reasons stated above.
An Apple iPhone 15 Pro Max listing on Argos, claimed to use “more recycled materials” without stating what the comparison was based on (e.g. with a previous model or other smartphones) or providing any evidence. This failed both the comparison and also substantiation checks included in the Which? study.
The CMA’s code says claims ‘must be substantiated’ but Which? found three in five products (62%) failed checks related to this principle. In fact, the vast majority of claims with no evidence (96%) provided no links, QR codes or references.
This included a description for Mr Organic Canned Chickpeas (taken from Ocado) which had multiple green claims relating to the chickpeas being organic and having “zero air miles” a term used to suggest a short distance or a mode of transport that has a smaller carbon footprint than a plane. While it did provide a certification for its organic claim, it did not provide any evidence or justification for its other claim of “zero air miles”. It then did not provide any links or references for consumers to check the evidence if they wanted to. Therefore, in Which?’s view, this example is more likely to mislead compared to one where links or references are provided.
The last principle Which? checked was that claims must consider ‘the full life cycle of the product or service’. An example of this issue was found by Which? researchers in the form of a product description for Adidas ⅞ Leggings (taken from Next) which claimed to be made from "85% Recycled polyester" and said “made with a series of recycled materials and at least 70% recycled content, this product represents just one of our solutions to help End Plastic Waste”. Although it is positive that the use of recycled polyester reduces the need for virgin materials, the description does not mention other significant issues that may be relevant to the product’s lifecycle, such as the release of microplastics from recycled polyester, the fact that it is not biodegradable if it ends up in landfill, and that the source of recycled polyester is often from recycled plastic bottles disrupting the bottle-to-bottle recycling loop.
Where products are sold through third-party retailers, it may not be clear who wrote the product descriptions. Brands do usually provide approved marketing wording to those retailers, but retailers may make edits, and updates made by the brand can take some time to trickle through. Product descriptions used may vary across retailers and from what is found on the brand’s own website.
While further investigation is needed to uncover whether green claims are actually true, Which? is concerned that misleading claims could erode public trust and the use of sustainability claims may be seen as more of a marketing tool than any real effort to be more environmentally friendly.
While regulatory bodies like the CMA and Advertising Standards Authority have taken some action against greenwashing, the scale of the issues uncovered by Which? suggests the Green Claims Code may not be working as it should.
Which? believes these findings highlight the need for stronger enforcement from regulators against firms that are misleading consumers and support for businesses that are serious about complying with the Code.
Lisa Webb, Which? Consumer Law expert, said:
"We know many shoppers are trying to shop more sustainably, yet this research shows they are being let down by vague or unsubstantiated claims.
“Misleading green claims don’t just waste people’s money - they also erode trust and give an unfair advantage to businesses that cut corners.
“We want to see stricter enforcement so that brands can’t get away with having vague claims about sustainability on products and eco-conscious shoppers can be confident in what they’re buying.”
-ENDS-
Notes to editors:
This research was conducted by Which? and London Economics.
The assessment framework used 24 checks derived from the CMA’s Green Claims Code.
The methodology combined AI analysis and consumer panel testing for robustness.
The investigation analysed 1,000 product listings from popular UK retailers, covering items in food, cleaning, electronics, clothing, and personal care.
To scale the analysis, the team used an artificial intelligence model trained to assess each product description against 24 rigorous checks derived from five key principles of the Green Claims Code:
- Claims must be truthful and accurate
- Claims must be clear and unambiguous
- Comparisons must be fair and meaningful
- Claims must be substantiated
- In making the claim you must consider the full life cycle of the product or service
Which? was unable to include the remaining principle:
- Claims must not omit or hide important information.
This is because after initial testing, Which? found that it was not possible to get the model to accurately identify what information was missing that could be considered important to a consumer.
All the examples mentioned have been subject to further human analysis.
Signs of Good Practice
Not all businesses failed. Which? highlighted examples where companies got it right:
Ocado’s Organic Vine Tomatoes were praised for clearly stating their Soil Association certification and control number in support of their ‘organic’ claim.=
Birra Moretti 18x330ml Lager also taken from Ocado states that it has ‘cut our emissions when making our beers and ciders by 68% since 2008’. The green claim presented in the product description does not use any vague / general terms. Instead, it is clear and specific about the environmental benefit of the brand.
Next Men’s Sweater includes one green claim about their Better Cotton initiative. Whilst it does not provide specific evidence why Better Cotton is ‘protecting and restoring the environment’, it does provide a link to the initiative for consumers to read about it.
Download the full report from Wednesday 2nd July.
Read the online news story here from Wednesday 2nd July.
The full report, How Green Are Green Claims?, is available now and offers vital insights to help regulators, businesses, and policymakers build a greener, more trustworthy consumer marketplace.
Right of replies
Adidas said the example mentioned is on a third party website that is not operated by Adidas and the wording is not in line with their current marketing communication.
However, it said the example is factually correct and offers full information about the composition of the product material with 85 percent recycled polyester and 15 percent elastane.
Apple said they are working with Argos and other reseller partners to ensure the language reflects the Green Code of Conduct.
An Argos spokesperson said: "We take our role as a responsible retailer very seriously and it’s important to us that customers are able to make informed choices when they shop with us. We offer thousands of products, from hundreds of suppliers and are working to review all product descriptions."
A spokesperson for Charlie Bigham’s said: “At Charlie Bigham's, we have always been about crafting delicious food for our consumers whilst also focusing on the long-term impact we have, both on the environment and the community. Part of that is that we believe great food deserves thoughtful packaging. That’s why, 18 years ago, we introduced wooden trays, sourced from PEFC-certified poplar and designed to be oven-friendly, compostable, and reusable. Since then, we’ve continued to improve, from switching to energy-saving red clay ceramic pots to using plastic film made with 30% recycled content and cutting plastic waste by 24 tonnes a year.
“When it comes to our cardboard sleeves, we removed the additional cardboard flap, thereby reducing material by 30%.
“For more details on this and our wider sustainability work across sourcing and food waste, visit charliebighams.com/our-purpose; to see our detailed Impact Reports for the last four years, visit https://www.charliebighams.com/our-purpose. And if you have ideas on how we can improve further, we’d love to hear from you... email hello@bighams.com”
Grind said that when selling through one of their retailers, the copy that they are able to provide and share is limited. They have all relevant sustainability information on their brand site.
Mr Organic Chickpeas said that in January 2022 it set out on its journey of rebrand which launched on shelf in January 2025. One thing highlighted for removal was the Zero Air Miles messaging and being clearer with consumers of the environmental and health benefits with our range and brand. It has rebranded its range of 120 products, which has taken time to roll out due to not wanting to throw away any old packaging for environmental reasons.
Next declined to comment.
Ocado said: "We work closely with our suppliers to ensure all the information they provide for our website is accurate. We also have a training programme and toolkits for our colleagues to make sure we're compliant and up to date with the evolving regulatory landscape."
When approached for comment, Tesco directed Which? to the BRC.
Tracey Banks, Climate Action Roadmap Manager at the BRC, said: “Retailers are responding to customer demand for more sustainable products, and the industry is working hard to ensure all green marketing is clear, accurate and substantiated, ensuring customers are able to make an informed choice about the products they buy. This is why many have joined the BRC-Provenance Retailer Green Claims Forum, which aims to help the industry share expertise on how it markets sustainability information in adherence to the CMA's Green Claims Code.”
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