Higg index is a unified sustainability measurement tool that uses data from across the textile, apparel, and footwear sectors. It enables brands of all sizes - to measure and score product’s sustainability performance. In comparison to other LCA measurement tools on the market, Higg provided the most extensive data derived from all stages of the manufacturing process, and the most comprehensive data to identify impact. This numerical approach helps us to identified opportunities for improvement.
There’re two major tools we use in order to assess the environmental impact.
Higg Materials Sustainability Index (MSI): A cradle-to-gate assessment tool for materials that use life cycle impact assessment data and methodology. It addresses impact from the extraction or production of raw materials, through manufacturing and finishing to the point where the materials are ready to be assembled into a final product. It help brands and manufacturers understand the environmental impacts and hotspots related to the production of different materials.
The production process consists of the below steps:
Higg Product Module:
The product module is designed to Calculate the environmental impacts of a finished product. The module uses lifecycle impact assessment data and methodology to measure product manufacturing footprints, including waste material derived during the process. (PS- New Higg Product Module which calculates the full cradle-to-grave analysis throughout lifecycle stages of the product - will include consideration of use and end-of-life, including material and product quality, repairability, and the use phase. will be released in the 1st Quarter of 2021. We will follow the update closely)
Primary data (data collected from the site of production) is also collected from the industry for specific processes and raw materials. Secondary data sources (publicly or commercially available datasets) include GaBi, the World Apparel Lifecycle Database (WALDB), ecoinvent, literature and SAC member input. The background database used for modeling uses the most current GaBi software version and Service Pack (Sphera).
Together with the database, the Higg Index developed modeling principles based on: GaBi modeling Principles, Ecoinvent data quality guidelines, ISO14040/14044, and PEF guide. The Higg MSI is updated twice a year to reflect new and updated LCA data, new materials, and new manufacturing processes from suppliers
The methodology and its limitations
Higg MSI framework uses various widely accepted LCIA methodology to calculate midpoints for the impacts.
Higg MSI framework uses various widely accepted LCIA methodology to calculate midpoints for the impacts: Global Warming, Eutrophication, Depletion of Water, Resource Depletion and Chemistry.
LCIA method based
Intergovenmental Panel on Climate Change. 2013. IPCC Fifth Assessment Report. The Physical Science Basis. https://www.ipcc.ch/
IPCC 2013 GWP100a global warming potential (GWP) LCIA impact methodology. This is the most broadly accepted and up-to-date method to measure greenhouse gas emissions.
Eutrophication is the result of nutrient loading, and is measured in Nitrogen and Phosphorous equivalents. Each waterway will respond differently to different nutrient loads.
more complex model, data for water use/ consumption is relevant at watershed spatially specific level, country level. Water availability varies over time and needs to be periodically updated in order to be accurate. Water availability is assessed at regionally specific levels. http://www.wulca-waterlca.org/
CLM, 2013 v4.2 Global. Energy use is a major driver of environmental impacts, and depletion of global resources is a widely recognized concern. assess the extraction and use of fossil fuel resources based on availability and access. Center of Environmental Science of Leiden University (CML). 2013. CML-IA Baseline. http://www.cml.leiden/edu/software/data- cmlia.html
The precision of USEtox is low, and the toxicity of substances are not consistent enough, therefore Higg uses a semi-quantitative model, and take chemical qualifiers (certification/standard) into consideration
We use Product Module to calculate the environmental impact of all the products. At this stage, it is limited to cradle-to-factory-gate. It lacks consideration of product usage and the impact of end-of-life.
The calculation is based on the main fabric, and excludes other materials that have lower than 10% of the total weight. For instance, trims (zipper, buttons, labels, rivets, etc.), other supporting fabric(pocketing, lining, etc) are not included in the scope of the analysis. We will continue to see the update of Higg on the trim, and research about the data on our end.
For blended fabrics, we calculate the footprint based on the percentage of the composition. (Example, a fabric consist of 90% cotton and 8% polyester 2% elastane, the impacts are a combination of 90% of impact attributed from cotton, 8% from polyester and 2% from elastane)
Compare, criticism & limitation
We calculate it is based upon the same weight as our product. And substitute the raw material that is produced based upon conventional practice.
Organic\recycle cotton against conventional cotton.
Recycle polyester against virgin polyester.
Tencel fiber against viscose.
Recycle nylon against virgin nylon.
Organic hemp against conventional hemp.
It is based on a cradle-to-gate approach. Meaning, it doesn’t consider the impact of the product after it’s sold to the customers, nor does it factors in the impact of the product at the end of its lifespan.
The single aggregated score methodology has received criticisms from the leather, silk, alpaca industry which accuse data used in MSI are incomplete, have a narrow-geographical focus, and ignorance on durability and longevity in assessing its environmental impact.
The geographical data may not reflect the whole picture. Cotton grew in different countries have various farming methods, however, the data Higg present is the one’s that is available - often provided by the cotton association in the U.S. Expending data source covering more geographic are needed to reflect farming methods in different regions.
Based on Higg Index’s calculation, polyester is better than cotton in some metrics(water pollution and scarcity, chemistry); slightly worst in other metrics(global warming and resource usage. It states that polyester has an overall lower negative impact. One of the criticism is because the polyester’s impacts are measured starting at the base chemical, instead of the extraction of fossil fuel, while cotton’s impact is measured at the point where the seed is planted.