Valentino topped the list of 15 fashion houses, while six brands came joint bottom on the ranking for failing to take any credible action on these environmental issues. The ranking, “Fashion Duel” rates Italian and French luxury brands based on a survey of three areas of the brands’ global supply chain: leather, pulp and paper and toxic water pollution.

According to Greenpeace, Valentino has already committed to eliminating all releases of hazardous chemicals and to Zero Deforestation in its products, while Dolce&Gabbana, Chanel, Hermès, Prada, Alberta Ferretti and Trussardi refused to even disclose information for the survey. Brands were evaluated based on how transparent their supply chains are and their willingness to make binding commitments to create fashion free from hazardous chemicals and rainforest destruction.

“Since the launch of Greenpeace’s Detox campaign in 2011, 15 major fashion brands have already committed to eliminating all releases of hazardous chemicals along their supply chain and products,” said Chiara Campione, of Greenpeace Italy. “If these major companies, and today Valentino, have taken the step, why should we expect less from all luxury fashion brands?”

Greenpeace is asking supporters and consumers to challenge luxury fashion brands to clean up their act and eliminate hazardous chemicals and rainforest destruction from their supply chains and products.