The index rates polyester as one of the world’s most durable fabrics, for example based on data on European polyester production from a plastics industry group, although the majority of the world’s polyester is made in Asia, typically using a dirtier energy network and less strict environmental regulations. The Higg classification for elastane, also known as Lycra or Spandex, is based on a study by the largest elastane producer in the world at the time, Invista, a subsidiary of the Koch Industries conglomerate. (Invista sold its Lycra business in 2019.)
The Higg index itself was created about ten years ago as consumers became increasingly concerned about sustainability, the environment and animal welfare. It coincided with advances in synthetic-based fabrics that were not only inexpensive but also had new features buyers craved, such as improved elasticity or improvements in the ability to wick away perspiration.
Many of the apparel brands that sit on the board of directors of the group that oversees the index benefit from two fashion megatrends that have benefited directly from advances in synthetics such as these: fast fashion and athleisure. For example, fast fashion giant H&M shows what it calls Higgs-based sustainability profiles alongside some of its products.
“Higgs members, many of them are fast fashion brands, and they all use mainly polyester. So it’s beneficial for them to give polyester a better rating,” said Brett Mathews, editor-in-chief of Apparel Insider, an industry-focused publication based in London. But the data used was “very poor,” he said, and “the net result is that the actual Higg score, which says this fiber is more durable than that one, is misleading to consumers.”
The Sustainable Apparel Coalition said company data was accurate, comprehensive and collected in accordance with industry standards. Any gap between European and Chinese polyester production would be small compared to other differences in textile production, such as the knitting or weaving process, it said.
H&M, which sits on the Coalition Board, said the index was based on “standardized and verified third-party information” and that the tool “was under constant development and improvement.” Walmart said the Higg wasn’t the only tool it used to improve the durability of its clothing, and it continued to assess the index’s capabilities. Invista did not respond to a request for comment.