Review highlights weaknesses in Apparel Sustainability Rating System

A review of a leading environmental impact tool for apparel finds that unless improvements are made, weaknesses in the underlying science could lead to misleading results, with potentially far-reaching consequences for the environment

Discussion Paper: Analysis of Data and Methods applied in the SAC MSIand Associated ToolsPrepared on behalf of: Australian Wool Innovation and the International Wool and Textiles Organisation (IWTO):

The authors are K. Watson and and S.G. WiedemannIntegrity Ag& Environment26/11/


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The Sustainable Apparel Coalition (SAC) is a non-government organisation that aims to reduce the environmental and social impacts of apparel, footwear and textile products, by providing a common approach for assessing a product’s sustainability performance and to drive behaviour improvement. The SAC has built a strong industry foundation with SAC member companies, which are estimated to represent over one third of global apparel and footwear production. Since its launch in 2010, the SAC has engaged in significant industry research and development to produce tools and datasets to measure sustainability, using an approach based on life cycle assessment (LCA). However, there are still areas of uncertainty, knowledge gaps and inconsistencies in this approach when it is compared to the relevant background LCA standards, and this limits the ability of SAC to reach their laudable goals. The aim of this paper is to provide a constructive summary of methodological issues, and practical recommendations, that the SAC could use to increase the scientific robustness of their tools, to achieve its environmental sustainability goals. This summary document was developed after a comprehensive review of the public SAC Higg Materials Sustainability Index (MSI) methodology, database and SAC communications of relevance, with reference to the International Standards from the 14040 and 14020 series, and the European Commission Product Environmental Footprint (PEF) guidelines.

This discussion paper has highlighted a series of issues, many that relate to inconsistencies with the international guidelines and best practice for LCA. This discussion paper concludes that to achieve its long-term vision of transforming the apparel industry so that it produces no unnecessary environmental harm and has a positive impact on the people and communities associated with its activities, SAC must address the following shortcomings in it’s methodologies. These are related to:

(1)          the guidance for comparative analysis and public disclosure;

(2)          the choice of system boundaries and functional unit;

(3)          the exclusion of important impact categories;

(4)          the choice of LCA method and handling multi-functionality;

(5)          data quality, transparency and handling of uncertainty;

(6)          weighting and normalisation; and

(7)          the comprehensive coverage of non-LCA assessed issues.

It is noted that the key issues raised here have the potential, if not addressed, to result in burden shifting, unintended consequences, and incorrect guidance from the MSI and associated tools. If not addressed, these issues could lead to less sustainable fibre choices, which may compromise the SAC’s goal of promoting a sustainable apparel industry.

Based on the analysis and discussion paper reported here, a list of key inconsistencies and risks to the scientific robustness of the MSI have been identified, and recommendations have been provided to rectify these. Overall, the discussion paper found that the provision of, and adherence to the appropriate Standards for LCA and best practice in LCA, would rectify most, if not all of the issues raised. The authors recognise that addressing these issues may, in some cases, be a substantial undertaking and therefore the following recommended ranking of key issues is provided:

i)             Development or adherence to Product Category Rules (PCRs) is a recommendation of this discussion paper, to improve consistency between datasets. In the interim, withholding results from public disclosure and comparison is a priority to ensure erroneous conclusions are not drawn.

ii)            Inclusion of the full life cycle in the MSI and use of the correct functional unit for textiles is an urgent priority. To be consistent with the raw material and manufacturing

stages, and to be consistent with good practice in LCA, an evidence-based approach, reflecting actual garment use and end-of-life by consumers is essential. Application of a durability approach, which has a weak correlation with garment lifetime during consumer use, is inconsistent with the MSI and good scientific practice, and may result in directing users towards choices that result in burden shifting.

iii)           Inclusion of currently omitted impact categories, such as microplastics, is a high priority to increase the coverage and relevance of the MSI.

iv)           Clarification of LCA methods is recommended, and consequential LCA (cLCA) methods with system expansion, are recommended, considering the goals of the MSI and associated tools.

v)            Inclusion of a quantitative uncertainty analysis and confidence intervals with all MSI results, and coefficient of variation’s with data sources, is strongly recommended to ensure only scientifically valid comparisons are made. In addition to this, a full justification of the use of proxy data is recommended, together with improvement in the description of methods and datasets used in the MSI.

vi)           Disclosure of non-weighted and normalised data is recommended in the MSI tool.

vii)          Inclusion of a broader range of impact categories, including those not easily assessed by LCA, is recommended, using a similar approach to how chemicals are currently handled in the MSI. This will provide a broader commentary to accompany results. For example, assessing renewability and biodegradability is recommended.

It is essential that this important work to improve sustainability of the textile industry continues, and that robust, accurate and reliable methods are used to generate results that can be trusted by all parts of the textiles supply chain, including consumers. Although further development of methodologies is necessary, SAC and their tool has the potential to significantly improve the sustainability performance within the industry, reducing environmental impacts of the global apparel, footwear and textile industries. In commissioning this discussion paper, the wool industry continues its constructive and science-based approach to promoting the assessment of environmental sustainability in the textiles industry.

Key Recommendations

1.      The MSI needs to include the full life cycle of products.

Currently, two main parts of the life cycle are excluded: the use phase and end of life.

The period of use – of active wear and care of a garment – is generally the highest impact stage.

How different types and kinds of clothing are cared for and the length of time they are used is known to vary significantly depending on purpose and fibre content.

Without assessing these factors, it is impossible to correctly understand the impacts from different clothing. 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.

2.      Microplastics must be included

Growing evidence of the significant environmental impacts of microplastics are coming to light, yet this important impact is currently left out of the MSI’s scoring. While ever this remains a gap, the scores are unbalanced.

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

While the science for measuring microplastics is still being developed, an interim accounting system could be implemented.

3.      Improve the underlying data

The reviewers found that the quality of data in the MSI was, in many instances, poor.

It is common practice in LCA – and other fields of science – to report the scientific confidence in the results, indicating whether the differences are meaningful or just “noise”.

But this has not been done in the MSI.

4.      Improve Transparency

Overall, the MSI lacks transparency in its use of proxy data and in description of its methods – a lack which weakens the tool’s credibility.

Proxy data from limited sources is used for many fibre types, meaning the assessments are assumption heavy. As there is no measure of the uncertainty of the results, it is impossible to know how influential these many assumptions are for the results.

Another lack of transparency lies in the MSI’s scoring methods. The MSI combines environmental impacts (energy, water, greenhouse gases, etc) into a single “score.” There is no agreed scientific way to say which of these is more important than another, and the methods used in the MSI to achieve this score are not publicly available, hence value judgements have been made to derive the MSI score.

The “raw” information that leads to the score should be, as a matter of good practice, provided and reported along with the scoring.

5.      Don’t Stop with LCA.

LCA based results currently reflect only a part 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 equation and need to be considered in a comprehensive environmental measurement.

Wool supports a sustainable Future

Naturally renewable, biodegradable, readily recycled, with low-cost of care, wool is a highly prized apparel fibre.

In its support of the well-being of the planet and its people, the wool industry supports a robust and scientifically defensible approach to environmental assessments in the textile industry.

The wool industry has been and continues to be an active contributor to the processes such as the Sustainable Apparel Coalition, and to the funding of much-needed research.

With a worldwide membership encompassing the wool pipeline from farm to retail, the IWTO represents the interests of the global wool trade. By facilitating research and development and maintaining textile industry standards, IWTO ensures a sustainable future for wool.