At long last, fast fashion companies are being scrutinized for "greenwashing," the practice of employing misleading marketing claims to convince consumers that a product is sustainable or eco-friendly.

In the UK, sustainability claims made by major brands including Boohoo and Asos are being investigated by the Competition and Markets Authority (CMA), the country's competition regulator. Last fall, the organization published the Green Claims Code, a set of guidelines stipulating that companies using green marketing "must not omit or hide important information" and "must consider the full life cycle of the product."

Both Boohoo and Asos said that they will cooperate with the CMA's investigation, rendering the future of their respective "sustainable" and "circular" collections shaky.

The UK's crackdown follows in the footsteps of several other regions reassessing the state of sustainability marketing. In June, the Norwegian Consumer Authority warned outerwear brand Norrøna and fast fashion giant H&M against using data from the Higg Index — a sustainability assessment tool created for the fashion industry — to substantiate its environmental claims.

And in March, the European Union proposed tougher regulations for brands and retailers looking to market their wares as green.

The debacle has even spilled over into the United States, where H&M has found itself at the center of a lawsuit alleging that the company has "created an extensive marketing scheme to ‘greenwash’ its products."

While fast fashion isn't the only sector that markets its products using misleading sustainability claims (the auto, beauty, and luxury apparel industries also come to mind), companies such as Asos and Boohoo produce and sell such a high volume of cheaply made garments that the dissonance between "eco-friendly" and "fast fashion" is especially deafening.

As the UK, EU, and US begin to consider greenwashing a punishable offense, companies might think twice before throwing terms such as "sustainable" and "circular" around. A more transparent fashion system is something we can all get behind.