The Sustainable Apparel Coalition (SAC) will be “retiring” the Higg Materials Sustainability Index’s (MSI) aggregated single score amid growing criticism about the accuracy of the platform’s cradle-to-gate methodology, which sought to help brands make eco-friendlier choices by comparing the environmental impacts of fashion’s most widely used materials.
The change, the SAC announced Monday, “paves the way” for a second edition of the Higg Product Module, which launches next spring and will include, for the first time, a more holistic consideration of a material’s use and end of life instead of only the environmental burden of its production.
The MSI, the first product to emerge from the Higg Index’s suite of sustainability measurement tools in 2011, employed third-party-verified data to distill the five environmental impacts of materials production—global warming potential, nutrient pollution in water, water scarcity, chemistry and fossil fuel depletion—into a single score meant to reflect the “best available peer-reviewed science.” Until the announcement, it was updated twice a year, with the most recent permutation released in August.
But animal fiber producers, including Australian Wool Innovation, the International Sericultural Commission and the Leather and Hide Council of America, have variously condemned the MSI over the years for rating the impact of synthetic materials such as polyester, acrylic and polyurethane orders of magnitude below silk, wool and cow-based leather and, in so doing, framing them as better-for-the-planet options.
In 2019, researchers Stephen Wiedemann and Kalinda Watson, in a study funded by Australia Wool Innovation, noted that “several significant” impacts and processes are excluded from the MSI, including the use phase, recyclability, biodegradability, resource renewability and microfibers.
“Without assessing these factors, it is impossible to correctly understand the impacts from different clothing,” they said. “It is also impossible to combat the problem of fast fashion if the amount of time a garment is used for is not taken into account.”
Last month, a coalition of leather industry groups—including the International Council of Tanners, the Brazilian Tanners Association, the Confederation of National Associations of Tanners and Dressers of the European Community and the Leather Working Group—asked the SAC to suspend the Higg Index MSI score for leather, “pending review of the underlying methodologies and data,” which they described as “out of date, unrepresentative, inaccurate and incomplete” and yoking leather with a “disproportionately high” score that has resulted in a negative perception of the animal hide.
“In the quest for improved sustainability, manufacturers will reference the Higg Index when designing products and making choices on materials,” they wrote in a letter dated Oct. 8. “On the basis of current Higg score, these manufacturers are deselecting leather in favour of fossil fuel-derived, unsustainable synthetic products. As such, we believe that the reputation and viability of leather and leather manufacturers is being unfairly damaged by an assessment that does not reflect the true nature of leather or indeed, the alternatives.”
Similarly, Rajit Ranjan Okhandiar, secretary general of the International Sericultural Commission, which represents the silk industry, wrote to the European Commission on Oct. 15 calling out “serious flaws and deficiencies” in the MSI that have “unfairly discredited natural fibers” and endangered the livelihoods of tens of millions of people in silk-producing countries such as China and India.
The International Alpaca Association, too, has publicly questioned how polyester made from crude oil can be more sustainable than naturally derived and biodegradable alpaca wool. (And indeed, People for the Ethical Treatment of Animals frequently touts alpaca’s abysmal MSI score—second only to silk among the worst performers—as one of the reasons brands should ditch the fiber.)
Amina Razvi, executive director of the SAC, says the pivot away from the MSI aggregated single score reflects not only the organization’s “intended evolution” of its focus from materials to the product level, but also because it wants to address the concerns of its materials stakeholders. While the retirement of the aggregated single score was initially planned to coincide with the launch of the second edition of the Higg Product Module, it has been “accelerated” as a result of ongoing engagement with other industry associations.
“In recent weeks, organizations from the leather, silk and alpaca industries reached out to us to convey concerns about their respective Higg MSI impact scores,” she wrote in a blog post Monday. “Although a number of the concerns raised about the Higg MSI are misinformed, we recognized an opportunity to both correct this misinformation while also extending our collaboration work and invite more stakeholders across the value chain into the ongoing conversation about measuring what matters.”
The second edition of the Higg Product Module, she added, will “ultimately empower members to shift their focus to the product level, where we can achieve a greater impact.” The SAC will also “strengthen” its efforts to glean new and updated life-cycle assessment data from industry stakeholders to “help ensure the highest quality and representativeness of the Higg MSI as part of our regular review process,” Ravzi added.
Michele Wallace, director of product Integrity at Cotton Incorporated welcomed the elimination of the single aggregated score as a “positive step.”
“Sustainability measurement tools need to balance ease with accuracy,” she said in a statement through the SAC. “Although single scores are easy to grasp, they do not address the inherent complexities of impact assessment. With this change to Higg MSI and the release of the Product Module with the full lifecycle, the Higg product tools will move closer to conformity with ISO standards.”
Others remain skeptical, however.
“The announced changes to the Higg MSI will make absolutely no difference,” Veronica Bates Kassatly, an indepedent analyst, told Sourcing Journal. “MSI users already have access to the five individual impact area scores and can use them any way they please. It’s those impact scores that are unsubstantiated and misleading. Deleting the aggregated single score simply makes the MSI’s bias in favor of plastic fibers less apparent.”