In a sea of unsubstantiated claims about sustainability, BoF’s Sarah Kent explains why it's so hard to measure impact, and what sort of regulation could be coming for fashion.     Background:    Concern about the environmental impact of clothing has swelled in the past few years. So too, has the practice of greenwashing. Right now, fashion marketing is flooded with eco-conscious messaging as brands dub their products “sustainable” without doing the groundwork to back up declarations. Consumers and regulatory parties are starting to demand more.    “What we're seeing is companies wanting to talk more about this, consumers wanting to know more about this, and regulators really sitting up,” said chief sustainability correspondent Sarah Kent. “It's this perfect storm where something that has been an issue that needed to be addressed for a long time is coming to a head.”    Key Insights:  With little oversight outside voluntary inter-industry initiatives and no regulation, a sustainable marketing free-for-all has swept over fashion.  European policymakers looking to crackdown on greenwashing are currently considering legislation about how impact across various environmental areas can be measured.  Several snags have inhibited any real progress on measuring sustainability, including bad data, tangled methodologies, and the presence of complex social factors that go beyond ecological impact.  Some brands have begun efforts to increase transparency and show consumers information on why their products are more or less sustainable. H&M has started to give items nutrition-style labels that tell buyers things like what level its materials rank on a scale of better alternatives. Allbirds attributes carbon calorie counts to its products, so consumers understand associated emissions.        Additional resources:  Green or Greenwashing: Who Gets to Decide?: European efforts to introduce standardised rules governing how brands backup environmental claims are fuelling a heated debate that stands to create winners and losers. The Sustainability Regulations That Could Reshape Fashion: Governments in Europe and the US are discussing regulations and policy proposals that could help steer the sector in a more sustainable direction. Fashion's Greenwashing Problem Begins with Bad Data: Fashion is doubling down on ambitious promises to clean up its environmental impact, but bad and misleading data are complicating efforts to build a more sustainable industry.     Join BoF Professional today with our exclusive podcast listener discount of 25% off an annual membership, follow the link here and enter the coupon code ‘debrief’ at checkout.    Want more from The Business of Fashion? Subscribe to our daily newsletter here.