Sustainability has become one of the most powerful marketing tools of fashion. Terms like “eco-friendly”, “conscious”, and “green” are widely used, from hangtags, websites, to social media campaigns, to lure customers into thinking they are making smarter, more ethical choices. But do we –as customers– know what each term actually means? Do the fancy green words have as much meaning as we think they do?
In the context of fashion law, these questions now matter more than ever. Sustainability is no longer just an abstract value that fashion uses for branding; it is a statement that can strongly influence consumer purchasing decisions. As greenwashing becomes a larger problem in the fashion industry, the gap between what brands claim they are and what they actually sell is no longer merely an ethical concern; it has become a legal one.
Why ‘sustainability’ became a legal issue
In recent years, sustainability has moved from a niche fashion margin to the mainstream. As customers gained awareness of the fashion industry’s environmental impact –from carbon emissions and water pollution to textile waste– many shoppers now actively seek out products marketed as “sustainable” or “green”. For instance, a consumer may prefer a sweater with a hangtag claiming it’s made from recycled polyester to a standard polyester one, believing these labels reflect environmental benefits.
What does this change mean for brands? Sustainability has become a priority for brands to address alongside design and price. This includes launching new “conscious” lines, like Zara, known for their ‘Join Life’ collection – highlighting recycled and “green” materials, and publishing impact reports to demonstrate their environmental responsibility.
However, there is a clear asymmetry of information, meaning consumers have no choice but to rely on whether the brand suggests that a product is environmentally better or not. This is where the law intervenes. Because sustainability-related terms influence consumer purchasing decisions, the law is involved when the terms are misleading, unsubstantiated, or exaggerated. This places them on par with false advertising, leading customers to believe they are buying something they are not. Under the shift toward sustainability, regulators are becoming increasingly involved in how fashion brands communicate sustainability.
The problem with vague green language
One of the core challenges in sustainability marketing is the use of broad, undefined, vague terms. Words such as “eco-friendly,” “sustainable,” and “responsible” appear appealing but provide no substantive information or clarity. Regulators have begun to challenge this practice.
In 2025, Italy’s competition authority (AGCM) fined the fast-fashion company Shein €1 million for misusing environmental claims. The regulator found that Shein’s sustainability wording was “sometimes vague, generic, and/or overly emphatic, and in other cases omitted and misleading”. For example, Shein promoted their ‘evoluSHEIN’ collection as sustainable and responsible, misleading consumers to think that the collection was made with materials that are fully recyclable materials, which was untrue.
In the United Kingdom, the Advertising Standards Authority (ASA) banned several sustainability-related Google ads by Nike, Lacoste, and Superdry after finding that the ads exaggerated environmental benefits and lacked proper evidence. The brands used terms such as “sustainable materials” and “combining style and sustainability,” which the ASA found difficult to substantiate and likely to mislead consumers.
These cases show that sustainability claims are judged on two different levels:
- whether they are factually correct, and 2. how they are perceived by consumers, regardless of the brand’s intent.
What do these terms actually mean, legally?
A common misconception is that sustainability terms have fixed, universal definitions. In reality, most of the terms used in sustainable marketing are not formally defined in law. Instead, regulators focus on whether the use of these terms can mislead consumers.
“Eco-friendly” and “Green”
These terms imply an overall environmental benefit. They can be high risk because regulators require brands to explain in detail what makes the product “eco-friendly” and to substantiate the claim with evidence. Because it is such a broad claim, suggesting a general environmental benefit, it is more likely to be challenged unless they have reliable, clear evidence.
“Recycled”
Compared to “eco-friendly”, the term “recycled” is much more specific. However, there is still no single global threshold that automatically decides whether a product qualifies as recycled or not. Problems can arise when a product is marketed as recycled without clarifying which part of the product is recycled, or what proportion of recycled material is used. To keep consumers better informed, the UK Competition and Markets Authority (CMA) has issued regulations requiring brands to clearly state whether the claim “recycled” applies to the entire product or only to certain components.
“Sustainable”
“Sustainable” is one of the most legally sensitive terms because it suggests a reduction of environmental impact across the entirety of a product’s lifecycle. For example, if a product improves one aspect –such as material sourcing– but keeps the other processes resource-intensive, it cannot be called “sustainable”. Unless brands can clearly explain the scope and basis of their claim for sustainability, regulators consider the term potentially misleading.
Rather than defining sustainability itself, regulators focus more on how sustainability claims are made. At the EU level, the new Green Claims Directive introduces requirements for substantiating environmental claims. Brands will now be required to back their claims with scientific evidence, specify if the claims apply to the whole product or only part of it, and avoid generic language that’s hard to prove.
In the UK, the CMA issued a sustainability terms guide for fashion brands, urging brands such as ASOS, Boohoo, and Asda to implement clear and accurate green claims. This included brands using clear, easy-to-read language, specific terms, like “organic”
Or “recycled” as opposed to vague terms like “eco” or “responsible”. By having brands provide regular reports, the CMA aims to build on the Green Claims Code and adapt it to the fashion industry.
Australia’s consumer regulator has taken a similar approach. The Australian Competition and Consumer Commission (ACCC) issued detailed guidance explaining how regulators assess greenwashing, including how imagery, colour schemes, and omissions can contribute to misleading claims.
Across jurisdictions, the emphasis is consistent: sustainability claims must be specific, evidence-based, and clearly explained.
What comes next
The growing number of investigations, fines, and regulatory guidelines signals a shift in fashion- sustainability is no longer an aspirational branding choice; it is regulated like any other product claim. For brands, this means greater legal risk if sustainability messaging outpaces reality. For consumers, it means clearer information and fewer empty promises. And for the fashion industry as a whole, it signals a move toward accountability and transparency, where “being conscious” must be demonstrated, and not just declared.
Author: Sunwoo Kang
Sunwoo Kang studies Fashion & Textiles and Business Administration at Seoul National University. She is interested in the intersections of fashion, law, and finance- particularly how creative industries operate within the systems of regulation and capital. Having worked in finance and as a content creator, she developed a deeper interest in the structure surrounding the fashion ecosystem. Outside of academics, she enjoys curating fashion archives and exploring fashion trends and predictions.
