Walmart, Nike, Target, JC Penney, Levi’s and fellow members of the Sustainable Apparel Coalition have unveiled the group’s index for measuring the environmental impact of apparel products across the supply chain.

The Higg Index is an indicator-based tool for apparel that allows clothing manufacturers and brands to evaluate material types, products, facilities and processes based on a range of environmental and product design choices.

This 1.0 version of the index was developed for apparel products and measures environmental outcomes in water use and quality; energy and greenhouse gas; waste; and chemicals and toxicity.

Future releases of the index, slated for 2013, will include footwear products and social and labor impact areas, the coalition said. The index eventually will be expanded to include quantitative data and metrics and feature an improved scoring method.

The current version of the Higg Index asks practice-based, qualitative questions to gauge environmental sustainability performance. It’s based on the Eco Index and Nike’s Apparel Environmental Design Tool. However, the Higg Index has been significantly enhanced through the pilot testing period, the coalition said.

The tool includes a Materials Sustainability Index, a cradle-to-gate assessment tool to give designers and the global supply chain information on the environmental sustainability of materials.

A group of 30 manufacturers and retailers launched the Sustainable Apparel Coalition last year to improve the environmental and social performance of the apparel and footwear industry, from water consumption and chemical use to waste and embedded energy in products.

Last month, Nike partnered with Random Hacks of Kindness in the Open Challenge for Sustainable Materials, an initiative that asks apparel designers and developers to use sustainable materials listed on the Nike Sustainable Materials Index.