LCA Terminology Questions
Q: What is LCA/LCIA?
A: Life cycle assessment (LCA) is an analytical tool used to to evaluate potential environmental impacts of a product during its entire life cycle as a result of flows to and from the environment (including emissions to air, water and land, as well as the consumption of energy and other material resources), over the entire life cycle of a product or service. The boundaries of an LCA should be clearly stated and consistently applied; typically LCAs are “cradle to gate” including impacts from raw material extraction (cradle) to the factory gate, or “cradle to grave” including impacts from raw materials, manufacturing, use, and end of life.
LCIA (Life Cycle Impact Assessment) an impact assessment is conducted in which the data are interpreted in terms of their environmental impact (for example global warming and eutrophication potential).
Q: What is background data?
A: Datasets cover all relevant environmental flows, such as resource extractions, emissions, as well as all material and energy inputs and products of an activity. Background datasets, such as raw materials and energy, are used to build models of each process. Using a single background database is important for consistency within the database. The Higg MSI 3.0 (2020) uses GaBi as its background database.
Q: What are system boundaries?
A: System boundaries are established in LCA for consistency across the product systems. Identifying the system boundaries ensures that comparisons between two products are including the same process stages. The boundaries in Higg MSI are “cradle to gate”; from the impacts of raw material extraction (cradle) to the material factory gate (finished material before it is transported to the assembly/finished goods processing) are included. Each production stage also has gate to gate boundaries (or cradle to gate for raw materials) which are kept as consistent as possible to allow direct substitution.
Q: What impact categories are covered in the Higg MSI?
A: The MSI has five impact areas included in scoring:
Global warming potential (kg CO2e)
Eutrophication (kg PO4e)
Abiotic Resource Depletion (MJ)
Water scarcity (m3)
There are also two inventory metrics displayed for each process that are not included in the scoring:
Biogenic carbon content (kg C)
Water Consumption (kg)
Q: What is GWP?
A: The characterization model was developed by the Intergovernmental Panel on Climate Change (IPCC). Factors are expressed as Global Warming Potential for time horizon 100 years (GWP100), in kg carbon dioxide equivalent (CO2e). A majority of this is emitted through the combustion and consumption of fossil-based energy sources. However, there are also several more substances and processes that contribute to climate change, including agricultural and soil emissions, landfill gas, and some refrigerants, which are characterized in terms of CO2 equivalents.
Q: What is biogenic carbon? Is it included in the score?
A: Biogenic carbon is carbon contained in biomass that is accumulated during plant growth. As a result, many natural materials store, or “sequester” atmospheric CO2 in the short term. In the Higg MSI, this is not subtracted from the Global Warming results, but displayed as a separate inventory metric. This is consistent with many standards for communicating LCA results and is because there is no way of knowing that the carbon is sequestered for 100+ years in a cradle-to-gate LCA since the end of life is not included. Note that biogenic carbon is measured in kilograms of carbon, not CO2. One kilogram of biogenic carbon is equivalent to 3.67 kilograms of CO2 (based on stoichiometric ratios). So a material that has 0.39kg of biogenic carbon has incorporated the equivalent of (0.39kg * 3.67kg CO2/kg C = ) 1.43kg of CO2.
Q: What is eutrophication?
A: This impact category measures richness of nutrients in a lake or other body of water, frequently due to runoff from the land, which causes a dense growth of plant life and death of animal life from lack of oxygen. This is measured in kg PO4 equivalent. Biobased materials tend to score higher in eutrophication compared to synthetic materials due to use of fertilizers on farms. The burning of coal also contributes to eutrophication.
Q: What is water scarcity? What is water consumption? How do the two metrics differ?
A: Blue water consumption has been added as an inventory metric and is not included in scoring. Blue water consumption measures water consumed during the production process, including water that is incorporated into the product or evaporated as part of the production process. This includes net water use (water input minus water output) and does not include green water (rain water) or gray water.
Water scarcity measures the potential of water deprivation, considering both water consumption and scarcity/region. The Higg MSI uses the AWARE method to analyse water scarcity. This is the new consensus method to measure water scarcity, recommended by the EU Joint Research Center and included in the EU Product Environmental Footprint (PEF) methodology. The AWARE metrics represents the relative Available WAterREmaining per area in a watershed after the demand of humans and aquatic ecosystems has been met. So, water used in more water scarce areas is more impactful than water use in an area without water scarcity issues. For global processes where the specific manufacturing region is undefined the Higg MSI uses the EF method global AWARE water scarcity factor.
Q: What is abiotic depletion of fossil fuels?
A: Abiotic depletion of fossil fuels measures the depletion of non-renewable fossil fuel resources like coal, oil, and natural gas. It is related to the Lower Heating Value (LHV) expressed in MJ of fossil fuel.
Higg MSI Questions
Q: Where does Higg MSI data come from?
A: The Higg MSI uses a variety of data sources. The main background data source is GaBi. Primary data inputs come from manufacturers, databases, literature, and trade organizations. Data sources for each material or process are listed in the Higg MSI under Meta Information when users click on a specific raw material or production process. Anyone may submit data to the SAC to be reviewed and used to score materials in the Higg MSI through the MSI Contributor.
Q: How are the Higg MSI scores calculated?
A: The midpoint score is the actual result from the impact assessment in kilograms of carbon equivalents, MJ, kg of phosphate equivalent, or cubic meters of water. After the impact results are calculated, normalization factors are applied and scores are derived.
The purpose of normalization is to contextualize these scores and create one common unit that can be added together. This helps users to see if the impacts are high or low compared to other materials and processes. The reference for normalization is based on the volume of the materials most used in the industry. More details on the normalization method can be found in the Higg MSI Methodology document . The total score consists of a sum of the five normalized scores (CO2, eutrophication, abiotic resource depletion, water scarcity, and chemistry) to get a single score.
Q: What is the difference between LCIA and Points?
A: LCIA stands for “Life Cycle Impact Assessment” and represents the environmental impacts in the unit of that impact category. For example, the kg CO2e, MJ, kg phosphate equivalent, or cubic meters of water. The points, or score, are the normalization impacts and all impact scores are in the same common unit. The process for normalization is described in the question above.
Q: How does Higg MSI update and improve data?
A: The Higg MSI is updated twice per year with new and changed processes listed so that users can know what is new and improved. There are several ways in which data in the Higg MSI may be updated:
- The first is when the background database is updated, such as annual GaBi Service Pack updates. In this case, the model isn’t changed and just the impacts are updated.
- The second is when a higher quality data model is available that better represents the specific process. The data quality is determined using four factors listed in the metadata and include the precision of the model and how recently the primary data was collected. In this type of change, the process scores tend to change more – sometimes up, sometimes down – but always with the intention that it is more accurate than before.
- The third is when new processes and materials are added to provide more detailed raw material and manufacturing options to choose from. This means that materials can be modeled with more specific impacts, allowing better accuracy and detail when measuring material impacts.
Q: How can I compare different raw materials or material processing options in the Higg MSI?
A: While process level raw material comparisons can be useful and interesting, it is important to examine the overall material impacts and not only look at the fiber level impacts. Some materials require different processing steps that have greater loss rates, so only looking at one stage does not always give a complete picture.
Further, sometimes it is difficult to completely align the boundaries across different material production stages (compared to the full cradle-to-gate material boundaries, which are aligned to the finished material gate). For example, natural fibers are already in fiber form at the Raw Material Source. For synthetic fibers like polyester, the Raw Material Source is in pellet form. This is because for continuous filaments the input is pellet form. For staple fiber polyester, the fiber formation is included in the yarn formation stage. Therefore, comparing staple fiber polyester to cotton fiber is not an even comparison unless the Yarn Formation stage is included for both materials as well.
Q: How are materials prioritized for addition to the Higg MSI?How does this addition take place?
A: Anyone may submit feedback to SAC regarding what materials are missing and should be added. SAC members review this feedback and prioritize those data needs based on what would make the tool most usable. Once a list is prioritized, SAC asks data providers, such as SAC members, Sphera, or Quantis, what prioritized data is available. If data is available from manufacturers, it is encouraged that those manufacturers submit data via the MSI Contributor.
Q: Is there a pre-defined timeline for integrating and scoring new materials?
A: Data submission for new materials and production processes may take place at any time. The time it takes to review submitted data varies. The Higg MSI is updated twice a year and the update includes whatever data is reviewed, scored, and approved by the times those updates take place.
Q: Is Higg MSI data verified?
A: All data entered into the Higg MSI is reviewed by the MSI Gatekeeper and Data Manager. Acceptance criteria includes:
- The data was correctly entered into the online platform
- Explanations of material production are clear and relevant production processes are accounted for
- The scope of the data is consistent with the defined boundary conditions
- Sources, vintage of the data (timeframe represented), source types, and methods for data collection are documented
- Methods used for data collection and decision making are scientifically and technically valid Assumptions and limitations are identified and plausible
- All calculations are correct
- All data are verifiable and reproducible
- The data submission is approved by the MSI Gatekeeper
- The processes are organized into the life cycle stages in the Higg Product Tool taxonomy
- The overall data quality is at a minimum “fair” or higher quality rated
- If an LCIA Submission, data and midpoints must have been previously reviewed by an independent external expert. This expert must not be or have been employed in a full-time or part-time role by submitting organization or the practitioner of the study. This person also must not have been involved in defining the scope or conducting the LCIA. A review report must be submitted along with the results.
Q: How often is the Higg MSI data updated?
A: The Higg MSI is updated twice a year. Users can see what changes took place with the most recent update in the change log.
Q: How can Higg MSI scores be communicated to customers/consumers?
A: There are specific communication guidelines that must be followed as part of any business to business (B2B) or business to consumer (B2C) communications. If Higg MSI users wish to share specific scores, it must be done in accordance with the SAC MSI communication guidelines.
Q: How is social performance scored in the Higg MSI?
A: The Higg MSI assesses environmental impacts of materials — social impacts are out of scope. The Higg FSLM assesses social performance of factories, and the Higg BRM assesses social performance of brands.
Q: Is the impact of microfibers included in Higg MSI scores?
A: The Higg MSI scoring does not factor in scoring around microfiber pollution yet. The Higg MSI only leverages methodologies that are more broadly accepted as inputs. A widely accepted methodology for microfiber measurement does not exist. Once a peer reviewed, published, consensus methodology is available, SAC plans to incorporate it into the MSI ranking, and weigh microfiber impacts amongst the other critical issues. This is an area that SAC is watching closely.
Q: Is material biodegradability considered in Higg MSI scores?
A: The research of impacts related to biodegradability of materials is ongoing and there is currently no sound method for inclusion. SAC plans to review methodologies with members when available.
Q: Why isn’t land use included in Higg MSI scores?
A: Prior to the initial launch of the Higg MSI, SAC members considered the following measures of land impacts for inclusion: Land Use Change, Land Occupation, and Soil Organic Matter. They were ultimately not included because it didn’t lead to a better understanding of material impacts. Land that is being used does not necessarily mean it leads to more impact, such as a loss of biodiversity. Furthermore, adding land use metrics does not necessarily change the relative impacts of scores – it only increases the segregation between natural and synthetic materials, showing more impact for natural materials.
Q: What about impacts associated with material use or disposal?
A: The Higg MSI is a cradle to gate assessment; it considers impacts associated with material production only. Impacts from subsequent lifecycle phases are considered in the Higg Product Module.
Q: How are regions considered in the Higg MSI?
A: Specific regions are only included if data for a particular raw material or process has been submitted, and that process always takes place in that specific region. Otherwise, a global average is used to represent the materials and processes shown in the Higg MSI. The Higg MSI aims to capture specific production processes that may typically take place in particular regions that lead to impact differentiation and specify those production processes in the tool.
Q: How is Chemistry handled in the Higg MSI?
A: The chemistry methodology in the Higg MSI assesses chemistry on a process level. The methodology is a semi-quantitative one, where USEtox impact results are an input but are further modified to account for process and inventory uncertainty. Essentially, a logarithmic normalization of the USEtox ecotoxicity LCIA results is used for a process to reduce variability. Then, those results are grouped into high, medium, or low. Additionally, if chemistry-related certification is used at a facility or for a particular material, it may be applied in the Higg MSI to improve the score. Read further detail in the appendices of the Higg MSI Methodology document.
Q: Why is BCI cotton classified under “chemistry certifications”, but CmiA is classified as a “raw material”?
A: While Global Warming Potential, Eutrophication, Water Scarcity, and Resource Depletion of Fossil Fuels are calculated using production data and LCA methodology, Chemistry is assessed using a mixed approach that includes qualitative modifiers based on the chemicals management requirements of different certifications and programs. BCI production information has not yet been integrated into the Higg MSI so it can’t be included as a raw material process but they have had their program assessed to the Chemistry Qualifier Survey and are included as a chemistry modifier. Meanwhile, CmiA has submitted the production data required to calculate the raw material process impacts so it is listed as a raw material process option.
Q: Is the ZDHC chemistry framework used as part of the Chemistry methodology in the Higg Index?
A: Yes. One area that is asked about in the Chemistry Qualifier Survey is about input chemicals management. The levels of the ZDHC pyramid and the levels within the Qualifier Survey are aligned. Another area of the Chemistry Qualifier Survey asks about the Chemical Inventory at either a Facility level or Product level. If there are minimum requirements for the level of assessment for input chemistry as part of the chemical inventory then this is also used as part of the Qualifier assessment. In both cases the Chemistry Qualifier Survey defaults to the lowest level that is consistently required. Currently, only material certification programs and facility certification programs are included but in the future we are looking to integrate and use Higg FEM data for measured chemicals management practices. This will mean that facilities that are completing the Higg FEM and are reporting the percentage of their chemical inventory that achieves each level of the ZDHC pyramid will be able to use this data to reduce material specific chemistry impacts in the Higg MSI in the future.
Q: How do other companies use the MSI?
A: Companies are using the Higg MSI for a variety of purposes, from setting science-based targets, to created preferred materials lists, to training designers on sustainability. You can read about specific use cases of the Higg MSI and other Higg Index tools on the SAC Website.
Q: Can I use the Higg MSI to calculate Scope 3 greenhouse gas emissions?
A: Yes, the Higg MSI can be used to calculate your Scope 3 greenhouse gas (GHG) emissions for Tier 4 to Tier 2 material impacts. For any public disclosure, please refer to our MSI Communications Guidelines. The carbon footprint for Custom and Example materials in the Higg MSI is calculated using the IPCC method (see “What is GWP ”). If the annual production volume (in kilograms) of a material is known, multiply the carbon footprint for that material by the production volume to determine the Scope 3 GHG footprint. If this is completed for all of a company’s materials, that company’s Scope 3 footprint is calculated! Example Materials can also be used as proxies to get an estimate. For instance, if 100,000kg of cotton fabric per year is purchased, you could use the Cotton Fabric example material even if it doesn’t match the exact production steps to create a first estimate of Scope 3 emissions.
Q: How does the Higg MSI handle data updates, data gaps and uncertainties?
A: The Higg MSI uses the best available data and is updated twice a year to handle data updates. The data is not static; we fully expect the data and results to change over time as better data is acquired and updated. We announce the data updates in advance and users can view the change log to understand what has changed. In some cases, proxies and reasonable estimations based on expert judgement need to be made. We aim to be as transparent as possible about data quality; the meta data for each process lists the data quality rating and other modelling notes are included as well. SAC and Higg Co plan to collect more, higher quality data over time through the following means:
- Prioritize and solicit data from the industry
- Industry stakeholders submit data to include specific raw materials, processes, or other Material specifications in the Higg MSI
Q: Can the Higg MSI be integrated with my PLM system?
A: Yes. An API of Higg MSI data has been developed to allow for PLM integration. To learn more about the API please read the Higg MSI API Overview.
Q: Can I use the Higg MSI data in my LCA software tool?
A: No, Higg MSI data is designed to be used only in the Higg MSI tool for a few reasons. We have specific agreements with database providers about the licensing conditions of the data. The Higg MSI also contains proprietary data from individual companies that would not want their data exposed in any more detail than we currently have (the LCIA midpoints) and full LCA inventory data is not available.
Further, the Higg MSI is not organized as a traditional database. The Higg MSI LCI datasets are built to function very specifically for the Higg MSI and it’s data structure. Many of the processes cannot be used on their own, but have to be combined with other processes in a particular way to represent a full kg of material.
Q: Where are all of the custom materials I saved in the old Higg MSI?
A: The new Higg MSI was completely rebuilt on the higg.org platform to create an integrated user experience and to add member requested features. It uses updated data, revised methodology, and includes additional customization options for making custom materials. Therefore, it is a manual process to transfer any data into the new system. If you would like your materials transferred for you, or if you would like to retrieve an Excel export of your previous to assist with transferring the materials yourself, please contact hannah.seabury@higg.
Q. Who can access the Higg MSI?
A. While the Higg MSI has been developed by the industry as a technical tool for business use, we welcome the fact that academics and other interested stakeholders are interested in learning more about it. Any individual interested in learning more about the Higg MSI can register on Higg.org. A variety of service levels are available, depending on user needs.
Material Specific Questions
Q: Why does it seem like bio-based materials score higher than synthetic materials?
A: This is primarily because of the impact areas chosen and the fact that the MSI is a cradle-to-gate assessment. All impact areas are weighted equally. Bio-based materials typically have a lot of resource use associated with raw material production compared to conventional counterparts.
Q: Why is it that woven materials score worse than knit materials?
A: More energy is required to weave fabric than to knit fabrics, generally leading to a higher impact. However, woven fabrics tend to be lighter than their knit counterparts of the same yarn size, so woven fabric impacts may be less when comparing materials on an area basis (rather than a one kilogram basis). This type of analysis will be possible in the Higg Product Module (Higg PM).
Q: What if my exact yarn size isn’t available?
A: SAC aims to make the Higg MSI more and more detailed; however, it is not possible to show all imaginable processes. The How to Higg guide provides guidance on how to select the right yarn process for your exact yarn size in the Textiles Yarn Formation Method section.
Q: Why has the PTFE score changed so much overtime?
A: The previous Higg MSI PTFE process has a reference year 1999 and was adapted from ecoinvent version 2.0 (current ecoinvent is version 3.6). According to Sphera (who developed the updated model), the difference is mostly due to the R22 refrigerant emissions, which are orders of magnitude higher in ecoinvent compared to GaBi.
Sphera has worked with Europe’s main producers of PTFE more recently (reference data of 2018), so we have more confidence in this data overall. However, since the dataset was produced using production data from Europe there could be differences amongst global production that are not reflected in this dataset. As with all Higg MSI process data, we will continue to review feedback and data sources to make sure that best available and most appropriate information is being reflected in the Higg MSI.
Q: Why is the score for silk so high?
A: The high impact comes from the heavy water needs for mulberry trees as well as eutrophication in the silk filament production stage. The Higg MSI offers scores per kilogram of material. As silk fabrics tend to be lightweight, the overall product impact differences can have a lower impact than the Higg MSI score conveys (as all materials in Higg MSI are on a per kg basis). The Higg Product Module (Higg PM), which assesses product designs and completed products, provides impact results for specific amounts of materials used in a product.
Q: What is the allocation methodology for cow leather and how does it compare to the Leather PEFCR?
A: The Higg MSI uses a cow leather dataset created by Sphera that implements economic allocation at the slaughterhouse. The Sphera model only includes cows raised for the meat industry and does not include milk cows, so no allocation factor for farming is applied. Currently an allocation factor of 3.9% is set for the cattle hides in the slaughterhouse in the Sphera model, while the PEFCR requires a 3.6% allocation factor. Therefore, the current difference between the environmental impact of leather using the PEF recommended allocation and the allocation in the Higg MSI dataset is marginal.
Sphera plans to update datasets to use the allocation factor recommended by the PEFCR in the future; when available, the MSI will be updated accordingly.
Q: Why is the score for hemp and flax so high?
A: The scores for hemp and flax are driven by water and eutrophication impacts. The eutrophication impact is coming from direct emissions to water (nitrate, phosphorus, etc.) during hemp cultivation. It’s also important to consider that this data is based on data in the Quantis WALDB database, but it is also one dataset that represents a “generic” fiber based on the best data available to us. Farms that have much more sustainable or unsustainable practices would need to submit data to us to be reflected. We are expecting to have more flax and hemp processes included in future updates of the Higg MSI.
Q: Why is the Higg MSI score for Alpaca so high?
A: The primary hotspot is Eutrophication during raw material production. It is primarily driven by ammonia emissions from alpaca farming. The nitrogen in the ammonia comes from alpaca excretion (the assumptions for which is based on IPCC 2006 numbers). Around 12% of nitrogen from excretion is assumed to volatilize as ammonia.
Q: Why is kangaroo leather impact so low compared to other leathers?
A: Kangaroos are commercially harvested from the wild, therefore no impacts are assigned from the on-farm/animal husbandry phase. Only processing and transportation impacts are included.
MSI Contributor Questions
Q: When should I use the MSI Contributor?
A: The MSI Contributor is used to submit a new raw material or process to the Higg MSI based on your own production data. By submitting your data to the Higg MSI (via the MSI Contributor), you contribute to an industry materials database of environmental information. You will be able to differentiate your materials from competitors’. Your will also contribute to an unprecedented repository of information and deepen environmental understanding within the industry. Finally, you will be able to use this information to make more sustainable decisions in your business. See the “Learn More” section of the MSI Contributor page for more information.
Q: How much does it cost?
A: Costs are based on the review and modelling time. Non-members pay $175 per hour. Members receive the first 10 hours for free, then it costs $175 per hour above 10 hours. The average submission takes 5-6 hours, but this is largely dependent on the complexity of the data, how it fits into our taxonomy, and the questions of the review team.
Q: How long does it take?
A: It can take several weeks to several months depending on both the complexity of the data, how many questions we have, and the timely response to our questions. Typically it takes a few months to go through the gatekeeping process and calculate the score. We do two data updates per year, so once the score is approved by you for publication in the tool, it will be scheduled for the next release.
Q: My product has chemistry certifications (like OEKO-tex), can these be included in the process with my submission?
A: No, chemistry certifications cannot be added to the materials by default. Rather, they are customizations that may be applied to a material by Higg MSI users. If a submission has a chemistry certification, the description to instruct users “if you select “XYZ material” you should also select OEKO-Tex and GRS”. Alternatively, the data submitter can create the correct custom material themselves and share it with customers (or both).
Q: Do I need to have an LCA of my product to submit data to the Higg MSI?
A: No, you do not! There are two types of acceptable submissions:
Type I: Material, energy, water, waste, and emissions can be submitted to our Data Manger to model in our LCA software.
Type II: If an LCA has been conducted and is aligned with our methodologies (outlined in the MSI methodology document), and it has been independently reviewed, characterized results life cycle impact assessment (LCIA) can be submitted to the MSI.
There are benefits and drawbacks to both types of submissions, see the below table for more details:
• The submission is more cost effective than conducting a full LCA since Higg Co will be responsible for modeling the data
• The data model will be updated using the most current background datasets, ensuring the best alignment with the rest of the Higg MSI
• If impact categories are added or changed in the Higg MSI there are no additional fees associated with re-modelling.
• Midpoints and final scores are integrated into the Higg MSI after approval by the Data Submitter.
|• Detailed production data will need to be submitted. Note: This information is only available to staff and contractors (such as the MSI Gatekeeper) who are required to guard the confidentiality of the information.|
• If you have already conducted an LCA, results can be reassessed to comply with Higg MSI methodology (i.e. re-use existing work)
• It is not necessary to provide the same level of production information to the MSI Gatekeeper, Data Manager, SAC, and Higg Co as is required for a Type I submission.
• The overall submission involves more steps and tends to be more costly. Supporting documentation of data and the LCA must be made available to and reviewed by an independent third party. A review report must be submitted along with the LCIA results.
• LCIA methodologies must match MSI LCIA methodologies exactly, which can require re-analysis of the existing LCA
• If the Higg MSI assessment methodology changes (e.g., for reasons to maintain consistency with the EU-PEF LCIA methods), updated data must be re-submitted. The fee for covering the quality assurance process will need to be paid each time.