An in-depth study by the consumer champion found that many popular products risk falling foul of rules designed to crack down on bogus environmental claims.
Researchers trawled through more than 20,000 online product listings using artificial intelligence (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 (CMA’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 and protect consumers from being misled.
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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 lifecycle of the product, and be substantiated.
The vast majority (84%) of products 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.
Lisa Webb, Which?’s 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.”
When it comes to financial products, Financial Conduct Authority (FCA) anti-greenwashing rules came into effect in May 2025. Businesses must now keep to a set of four principles so their statements about how sustainable or environmentally friendly their products do not mislead customers or investors.
