 Asos PLC and Primark have both come out with pledges to make their clothing more sustainable, as competition among fast-fashion retailers has reached boiling point this year. The environmental, social and governance ESG reputations of rivals Boohoo Group PLC and Chinese newcomer Shein are not the best, so the more established UK pair seemed to be looking to gain ground in an area that is important to some but by no means all of their predominantly young customer base. 