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Reviewers of a leading environmental impact tool for apparel find that its systems must improve, or it risks producing misleading results.

A number of environmental impact tools have been developed in recent years.  These tools aim to measure the environmental footprint of apparel products. One such tool is the Sustainable Apparel Coalition’s Material Sustainability Index (MSI). It is one of the suite of tools in the Higg Index.

Dr Stephen Wiedemann and Dr Kalinda Watson of Integrity AG & Environment (Australia) reviewed the MSI with specific reference to fabrics made from natural fibres, making several key recommendations. These recommendations would bring the Higg tool into alignements with ISO standards, and establish a level playing field for rating both natural and syntheric fibres.

Read the full review in the peer-reviewed journal Sustainability.

Where the MSI Needs to Improve

In their review, Drs Wiedemann and Watson found that the Higg MSI in many places does not comply with international best practice guidelines. Because of this, the MSI does not present a reliable measure of impacts to the environment.

However, the researchers concluded that most of the problems could be solved by bringing the MSI in line with international standards.

“We need robust, accurate and reliable methods to generate meaningful ratings ,” said lead researcher Dr Wiedemann.

“Most of the issues we found can be resolved by adhering to International Standards and guidelines for best practice in LCA. The result would be a stronger tool that would be more likely to help the apparel industry become sustainable.”

Key Findings

The review makes five key recommendation for improvement.

1. Include the full life cycle

Currently, two main parts of the life cycle are excluded from the MSI: the use phase and end of life. Yet, the period of use is generally the highest impact stage.

By excluding the impacts from wear and care, which are known to vary by fibre type, the MSI misses substantial information. Without this information, it is impossible to fully understand the true environmental impact.

Read more: First Full Wool LCA Reveals Importance of Use Phase

2. Include microplastics

One of the top three causes of microplastics pollution is shedding from synthetic clothing. Any robust assessment of environmental impacts to textiles must include microplastic fibres.

There is growing evidence of the significant damage being done by microplastic fibre pollution. But, the MSI excludes it from the scoring.

Certainly, even while the science for measuring microplastics is still being developed, an interim system could be used.

3. Improve the underlying data

The reviewers found that the quality of data in the MSI was often poor. In addition, it is common practice in LCA – and other fields of science – to report how confident one can be in the data. But this has not been done in the MSI.

Both of these issues urgently need to be addressed.

4. Improve transparency

Overall, the MSI lacks transparency in its use of proxy data and in description of its methods.

Firstly, for many fibre types, the MSI uses proxy data from limited sources. The MSI is therefore what scientists call  “assumption-heavy.” But because there is no measure of the certainty of the results (point 3, above), it is impossible to know how influential these many assumptions are.

Secondly, the MSI’s scoring method is not transparent.  The MSI combines several impacts into a single “score.”  The method applie different weightings to each impact.

Science does not agree which environmental impacts are more important. Thus, as a matter of good practice, the weightings should be reported along with the final score.

5. Don’t stop with LCA

LCA can only measure some of the environmental impacts of a product. Renewability, biodegradability, carbon cycling and biodiversity are all aspects which, although difficult to integrate into LCA, are part of the environmental reality.

Therefore, they need to be considered in a comprehensive environmental measurement.

Read the full review in the peer-reviewed journal Sustainability.

Wool Supports a Sustainable Future

Wool is a highly prized apparel fibre that is naturally renewable, biodegradable, and readily recycled.

In its support of the wellbeing of the planet, the wool industry calls for a robust and transparent approach to environmental impact measurements for textiles. Australian Wool Innovation, an IWTO member, funded this review of the MSI. Dr Wiedemann is Chair of the IWTO’s LCA Technical Advisory Group.

Learn more about wool’s sustainability here.

Or try one of our Fact Sheets or Wool Notes, a guide to all things wool.

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