Major UK fast fashion retailers will change the way they promote the environmental credentials of their clothes after being accused of greenwashing by a UK watchdog.

Asos Plc, Boohoo Group Plc and Asda’s clothing brand George have signed formal agreements with the Competition and Markets Authority to use only “accurate and clear” green claims, according to a statement Wednesday.

The requirement includes displaying information clearly to shoppers, avoiding using vague terms to describe organic or recycled fabrics and using misleading imagery, such as green leaves to suggest a product is more environmentally friendly than it is.

“The commitments set a benchmark for how fashion retailers should be marketing their products, and we expect the sector as a whole — from high street to designer brands — to take note and review their own practices,” said Sarah Cardell, chief executive officer at the CMA.

Fast fashion brands, which are able to respond to ever-changing trends at low prices, have come under pressure for their high carbon footprints.

Boohoo CEO John Lyttle said the agreement provides “some helpful clarity” and that his business remains committed to finding “collective solutions” to make fashion more sustainable.

A spokesperson for Asda said it worked pro-actively with the CMA and is pleased to come to an agreement. A statement from Asos said it welcomed the CMA’s commitment to ensuring standards are applied across the whole industry.

By Jennifer Creery

Learn more:

Asos Sales Fall Again Amid Turnaround of Fashion Retailer

The troubled online clothing retailer said that sales fell 18 percent in the six months to March 3, which was broadly in line with guidance.