Have a symbol on thumbnail with legend for the symbols on the website to include a highlighted rating of the social and environmental compatibility/standard of garments
eg 1 green leaf = 100% cotton for biodegradability
2 green leaves = 100% cotton + certified sustainably sourced
3 green leaves = 100% cotton + certified sustainably sourced + fair trade supply chain etc

Alternatively, apply a default stringent vetting on supply chains of suppliers/manufacturers to incorporate these measures and expand on ethically sourced items.