Background
This ruling forms part of a wider piece of work investigating environmental claims in the retail fashion sector. The ads were identified for investigation following intelligence gathering by our Active Ad Monitoring system which uses AI to proactively survey ads in specific sectors. See also related rulings published on 3 December 2025.
Ad description
A paid-for Google ad for Nike, a clothing retailer, seen on 18 June 2025, stated “Nike Tennis Polo Shirts – Serve An Ace With Nike[…]Sustainable Materials”.
Issue
The ASA challenged whether the claim “sustainable materials” was misleading.
Response
Nike Retail BV t/a Nike said the ad was framed in general terms and was intended to call out the benefits relating to a wide range of Nike products and services, rather than being specific to a particular product or service. The ad included a range of promotional claims, such as discounts, delivery and payment options, as well as the reference to “sustainable materials”.
Nike said the reference to “sustainable materials” in the ad was intended to reflect the availability of products on Nike’s website that incorporated recycled materials. In their view, consumers would reasonably interpret the reference to “sustainable materials” as indicating that some, but not all, products offered by Nike contained materials designed to reduce environmental impact, such as items made from recycled polyester, and that further information was available on the Nike website to support informed decision making. They acknowledged that sustainability attributes might vary across their products, but that they aimed to provide clear and accessible information on individual product pages to support transparency.
The ad was a paid-for Google ad, which had character limitations of 30 characters for the headline and 90 characters for the body text. Nike said that limited the level of detail they could provide in the ad, and that it was not possible to provide a full description of the products or services referenced, or to include all relevant qualifying information in the ad. However, they aimed to ensure that consumers were able to access specific and substantiated product information as they progressed through the customer journey on their website.
When consumers clicked on the ad, they would have been directed to the product wall on Nike's website showing all Nike tennis polo shirts available at the time the ad was live. Some of those shirts included a “sustainable materials” banner. Nike explained that a product listing could only feature a "sustainable materials" banner if it contained a minimum of 50% recycled materials. All of their Summer 2025 tennis polo shirts contained at least 75% recycled materials and, therefore, qualified for the “sustainable materials” banner. Individual product listings provided additional information on the product’s composition via a drop-down tab “How this was made” which also included a link to Nike’s sustainability page.
Nike used a third-party tool, Higg MSI, to assess the environmental impact of their materials and to support their environmental claims. The tool provided industry-average data on the environmental impacts of different materials They provided a screenshot of the Nike Higg MSI data showing the environmental impact of using recycled polyester (which was used in Nike tennis polo shirts) on a cradle-to-gate basis – that showed a reduction in CO2 equivalent as compared to non-recycled polyester. They considered the data to be a meaningful and relevant indicator of environmental benefit, particularly given that the downstream stages (such as distribution, use, and end-of-life) were not expected to differ materially between recycled and non-recycled polyester products.
Nike said that the ad was no longer live and was taken down in June 2025 as part of their standard advertising practices.
Assessment
Upheld
The CAP Code required that the basis of environmental claims must be clear, the meaning of all terms must be clear, and that absolute environmental claims must be supported by a high level of substantiation. Claims must be based on the full life cycle of the advertised product, unless the ad stated otherwise.
The Competition and Markets Authority guidance ‘Complying with consumer law when making environmental claims in the fashion retail sector’ (the CMA Guidance) stated that broader, general or absolute claims such as “sustainable” were likely to mislead consumers, and that their meaning was unclear. It further stated that consumers were likely to assume from the use of the term that the product about which it was used as a whole had a positive environmental impact, or at least no adverse impact. The ASA had regard to the guidance in assessing whether the ad had complied with the CAP Code.
The ad included the claim “sustainable materials” and did not include qualifying information explaining the basis of the term “sustainable”. We considered the ad was not limited by time or space to such an extent that the information could not be provided and, without qualification, the “sustainable” claim was ambiguous and unclear. The claim was absolute and therefore a high level of substantiation in support needed to be produced. While ambiguous, we considered the term “sustainable”, in the context of the ad, was likely to be understood as meaning that all Nike tennis polo shirts, across their entire life cycle, would at the very least have no detrimental impact on the environment.
We understood that Nike tennis polo shirts contained at least 75% recycled materials, such as recycled polyester, and that recycled polyester, on a cradle-to-gate basis, resulted in a reduction in CO2 equivalent as compared to non-recycled polyester. However, Nike had not provided evidence to demonstrate that their tennis polo shirts had no detrimental effect on the environment, taking into account their entire life cycle.
The basis and meaning of the claim “sustainable materials” had not been made clear, and we had not seen evidence to support it. We therefore concluded the ad was likely to mislead.
The ad breached CAP Code (Edition 12) rules 3.1 (Misleading advertising), 3.7 (Substantiation), 11.1, 11.2, 11.3 and 11.4 (Environmental claims).
Action
The ad must not appear again in the form investigated. We told Nike Retail BV t/a Nike to ensure that the basis of future environmental claims, and their meaning, was made clear, and that a high level of substantiation was held to support them.
