Life Cycle Assessment (LCA) is a fundamental tool for calculating, managing, and mitigating the environmental impacts of products or services.
“LCA studies the environmental aspects and potential impacts throughout a product’s life cycle (i.e. cradle-to-grave) from raw material acquisition through production, use and disposal. The general categories of environmental impacts needing consideration include resource use, human health, and ecological consequences.” (ISO 14044:2006)
The concept of LCA emerged in the late 1960s and evolved into a structured methodology during the late 1980s. The first comprehensive framework for LCA was established with the publication of the ISO 14040 series in 1997.
Despite the robust framework provided by ISO standards, the practical application of LCA often encountered challenges, including:
Complexity: mapping the life cycle stages and assessing the impacts was not straightforward. The data collection, modeling, and analysis can be complex and time-consuming.
Unrealistic requirements: Meeting the exhaustive requirements of traditional LCA methodologies may not always be feasible within time and resource constraints.
Scalability: Traditional LCAs are not scalable because of the limitations of tools used by LCA practitioners.
There is a growing need for a technological solution to solve the complex issues and make LCA more accessible and scalable for the industry.
This is why at Yook, we strive for a pragmatic approach to LCA. Our focus is on crafting a software solution that is performing LCA at scale and looks into the entire expansive product portfolio. Our effort is to keep the balance between pragmatism and scientific precision.
LCA, as defined by ISO 14040, has four key stages:
Goal and Scope Definition: In this initial stage, we precisely define the purpose, functional unit, and boundaries of the assessment.
Life Cycle Inventory (LCI): It is now time to collect the relevant data points. This entails gathering data from the extraction of raw materials to manufacturing, distribution, utilization, and eventual disposal.
Life Cycle Impact Assessment (LCIA): We need to understand the environmental impact attributed to a product. Here is a step where we translate all the compiled data into the form of an environmental indicator (Environmental impact assessment indicator). Different categories such as Global warming potential, Primary energy consumption, Toxicity, Water usage, land usage, and many more are evaluated at this stage.
Interpretation: Time for analytics! This stage involves a thorough analysis and understanding of the results. Based on the results from LCIA, we make conclusions and recommendations for carbon reduction strategies, product modification, or better sourcing, to name a few.
Yook's approach at a glance:
Yook conducts streamlined Life Cycle Assessments with a focus on the products' global warming potential (GWP 100) -IPCC 2021- measured in Kg CO2e.
The products’ life cycle is analyzed on a cradle-to-gate basis, meaning that upstream activities, production, transport, and packaging are included while distribution, use, and end-of-life are excluded from the analysis.
We conduct attributional LCAs and apply cut-off allocation or the PEF Circular Footprint Formula (CFF) if applicable.
Our methodology follows the GHG Protocol Product Standard and follows sector-specific guidelines, for example, the EU PEFCR. In addition, we can follow sector-specific guidelines, for example, the EU PEFCR, or apply sector-specific requirements, for example for differentiating FLAG- from non-FLAG emissions or to be able to use the data for CBAM reporting
In the LCA journey, the first step is to define a clear goal and scope for the analysis.
As there is no single source of truth for LCA, the first phase, Goal and Scope Definition, plays an important role and determines the cooking recipe depending on the objectives.
Different LCA approaches can be applied depending on the objectives and data availability.
Some areas to consider are:
Depth of the analysis: screening LCA for hotspot analysis, or would you like product-level insights?
Scope and limitations: cradle-to-gate LCA with a single impact focus on global warming or cradle-to-grave with multiple indicators?
Compliance: Choose regulations and standards to follow. This will directly affect the modeling of the product.
The least complex but also the least granular approach is the spend-based carbon footprint calculation, using monetary emission factors depending on the product category.
The activity-based approach can be applied to enhance the assessment. This assessment is based on the physical flows within the product system boundaries. As the first step, the average data from databases can be used. In the following step, the results can be enriched by using supplier-specific data.
Let's dive into each approach:
The spend-based calculation uses general emission factors (EFs) and only considers a product's price and category. The relevant emission factors indicate [Kg CO2e/EUR spend]. As the required input data is mainly accessible, the assessment is relatively easy.
However, some disadvantages are:
No possibility to account for differences in one product category
Price or spending is not a sufficient proxy for climate impact due to the volatility of CO2e results because of externalities (e.g., inflation, price reductions)
When a price discount is offered, the PCF decreases, though it´s the same product
Higher-priced goods, e.g., luxury brands and sustainable options, result in a higher product carbon footprint compared to low-priced products
Based on our experience, retailers might be motivated to conduct LCA for carbon accounting reporting. In such cases, exact product data might be missing. Therefore, initially, a spend-based analysis can be a useful starting point to get an overview of hotspots and important reduction levers.
The case below shows that the granularity of a spend-based calculation is not sufficient to explain variation in one product category. As it's only determined by product category and the product's price.
paper, white
1,49
paper and cardboard
1,09
1,62
9
paper, recycled
3,99
paper and cardboard
1,09
4,35
9
The activity-based calculation is more complex but also as more accurate. Depending on the granularity of the study, three methods are available :
The average-data approach uses industry-specific default data for a defined product category. In this approach, the granularity depends on the available industry and product category average data.
The supplier-specific approach requires specific, primary data along a product's supply chain to conduct an LCA. This method helps to determine the precise environmental impact of a specific product.
The hybrid approach combines the methods mentioned above, using a mix of supplier-specific data whenever available and average data to fill gaps.
Curious to learn more? This scientific article provides more detailed insights into each of these approaches.
The functional unit specifies the unit of analysis for the LCA study, such as one kilogram of product, one kilometer of transportation, or one hour of service. It defines the reference quantity against which all inputs and outputs are measured and compared.
At Yook, the functional unit is specified as one product.
Environmental impact indicators are essential components of LCA, as they provide a structured framework for quantifying and assessing the environmental burdens across different stages of a product's life cycle.
Here are the key environmental impact indicators commonly measured in LCA studies:
Measures the potential of greenhouse gas emissions to contribute to global warming over a specified time horizon, typically 100 years.
It is expressed in terms of carbon dioxide equivalents (CO2e) and encompasses emissions of carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and other greenhouse gases.
Quantifies the potential for sulfur dioxide (SO2) emissions and nitrogen oxides (NOx) to acidify the environment, leading to acid rain. It assesses the impacts on soil, water bodies, and vegetation, which can harm ecosystems.
Evaluates the potential for nutrient emissions, such as nitrogen (N) and phosphorus (P), to cause eutrophication in water bodies. Excessive nutrient levels promote algae growth, leading to oxygen depletion and ecological imbalance in aquatic ecosystems.
Measures the potential of substances, such as chlorofluorocarbons (CFCs) and halons, to deplete the ozone layer in the stratosphere. Ozone depletion increases the harmful UV radiation reaching the Earth's surface, posing risks to human health and ecosystems.
Evaluates the potential for substances to cause harm to human health through various exposure pathways, including ingestion, inhalation, and dermal contact. It considers both acute and chronic toxicity effects and helps prioritize substances based on their hazardous properties.
Assesses the potential for substances to cause harm to ecosystems and non-human organisms, including aquatic and terrestrial species. It considers the toxicity of substances to different organisms and ecosystems, helping identify environmentally sensitive areas.
Quantify the amount of land occupied or transformed by a product or process, including direct land use (e.g., agriculture, infrastructure) and indirect land use (e.g., habitat destruction). They help assess the impacts on biodiversity, ecosystem services, and land availability.
Water use
Assesses the consumption of water resources.
By integrating these indicators into LCA studies, stakeholders can identify hotspots, prioritize improvement opportunities, and promote sustainable decision-making to minimize environmental impacts.
At Yook, we are currently calculating carbon footprints. We focus on the climate change impact category, which measures the global warming potential (GWP 100).
Whenever possible, we constantly use updated emission factors from reliable databases and primary data. We constantly use updated emission factors from reliable databases and primary data whenever possible.
Note: Additional environmental impact categories might have relevant effects and can lead to trade-offs or unwanted burden shifting.
The system boundary includes all life cycle stages of the product, process, or service, from raw material extraction and production, distribution, use, and end-of-life disposal (cradle to grave).
Raw Material Acquisition: Includes activities such as resource extraction, agricultural production, and material processing.
Manufacturing: Encompasses all processes involved in the production of goods or the provision of services, including assembly, fabrication, and packaging.
Distribution and Transportation: Involves the transportation of the raw materials, components, and finished products between different stages of the supply chain and to end-users.
Use: Covers the operational use of the product or service by consumers, including energy consumption, maintenance, and product performance.
End of life: Addresses the disposal, recycling, or recovery of materials and energy at the end of the product's life cycle, including waste management and recycling processes.
In some studies, the boundaries can be to the gate of the distribution (cradle to gate). At Yook, our current model is cradle-to-gate. This means we include all upstream and core activities while the downstream activities are excluded.
Here is an example of a product system with cradle-to-gate system boundaries.
Allocation refers to assigning environmental burdens or benefits among multiple co-products or processes within a life cycle system.
Allocation is necessary when a product system yields more than one product or service simultaneously or when a process produces the desired product and by-products or co-products.
According to ISO 14040/44, there are three choices in the case of multi-output processes:
Avoid allocation by system expansion: Employing this strategy, particularly in consequential Life Cycle Assessment (LCA), helps to sidestep the complexities associated with allocation.
Physical relationships allocation: Allocation factor based on dry mass or volume of the co-products: Simplifying the process, this method ensures a fair distribution of environmental impacts across the system based on the physical properties of the co-products.
Allocation by other relationships (e.g., economic): Use the price of the co-products to determine allocation factor: By considering economic factors, such as the price of co-products, this approach offers a straightforward and transparent method for determining allocation, enhancing the accuracy and reliability of LCA assessments.
Now, we are getting a bit deeper into LCA Theory. But let's start smoothly:
One case is when multiple products are interconnected or share standard processes. In such cases, also called multi-output processes, it can be challenging to precisely attribute the environmental impacts to a specific product.
Example is:
Another case is the recycling process.
Regarding recycled materials, we also have two interlinked products: The virgin material recycled in its end-of-life phase and the resulting recyclate. This raises two questions that require an allocation decision:
which material bears the burden of the recycling process? Is the virgin material in the End of Life (EOL) phase or the recyclate in the material phase?
how is the burden of virgin material extraction allocated? Is it only to the virgin material, or is a portion also allocated to the recyclate?
There are some alternatives as the solution.
Burdens or credits associated with materials from previous or subsequent life cycles are not considered.
For example, scrap input to the production process is considered to be free of burdens, but equally, no credit is received for scrap available for recycling at end-of-life.
Hence this approach rewards the use of recycled content but does not reward end-of-life recycling.
In the substitution approach, the environmental burdens or benefits of co-products are allocated based on their potential to replace other products or materials in the market.
This method assumes that the co-products can be used as substitutes for virgin materials or products, thereby avoiding the environmental impacts associated with their production.
Example: In steel production, if the slag generated during steel production is used as a substitute for virgin aggregate in construction materials (e.g., road base, concrete), the environmental impacts of producing the slag would be allocated based on the amount of virgin material it replaces. This approach considers the avoided impacts of using the co-products as substitutes.
Alright! Now that we know about multi-output processes and allocation, let's head over to the next topic: Attributional versus Consequential LCA.
The analysis would focus on comparing the direct environmental impacts of producing the two types of packaging over the life cycle (raw materials, production, etc.) for both packaging types.
Result: The LCA might show differences in carbon impacts between the two materials.
The analysis would go beyond the immediate impacts and consider the broader consequences of the material switch.
This assessment accounts for potential changes in market behaviors and technology adoption
Result: It would provide an understanding of the overall carbon impact due to market changes.
Here is a comparison of these two approaches:
Environmental impact in its current state
Environmental impact of changes
Inputs and outputs are attributed to a product.
Activities are linked. Thus, the product system adapts to changes.
Direct and indirect impacts associated with the production, use, and end-of-life of a product
Includes indirect effects beyond the direct system boundaries and considers the consequences of decisions
Analysis of product environmental impact and product optimization within specific system boundaries
Broader analysis such as market changes or policy decisions e.g. changes in market prices and subsequent effects
You might wonder what is the most relevant method for your product. Currently, there is not a single LCA standard applicable across all product categories. Therefore, facilitating easy comparison of LCAs does not exist. Instead, there are numerous guidelines, standards, handbooks, and sector-specific initiatives, which can be daunting to navigate.
At Yook, we diligently monitor regulations within each industry sector and employ the widely accepted methodologies available.
To learn more about the regulations, please check our Climate Regulation Jungle. We have thoroughly reviewed and provided an overview of the different guidelines.
Life Cycle Inventory (LCI) is the second step of LCA. Here is where you need to collect all the data points required for LCA.
Your data doesn't need to be perfectly complete. Yook's software can work with every type of data. Whether complete or incomplete, whether automated data exchange via API or manual CSV exports - We have you covered. Data gaps are closed by our software and we guide you toward collecting the most relevant and vital data points with the help of our accuracy metric. make
We collect your product data using manual or automatic exports from your ERP/ PLM system. In general, we work with every data point available. But keep in mind that, the more and better data points are available, the more accurate the result is ( see the Accuracy Score).
Important data points over the product's life cycle are weight, material composition, origins, production methods, as well as supply chain data, and packaging information. We use sector-specific guidelines and industry-specific proxies in case of data gaps. Thus, most of the data points are already available in a BOM export. Additional information, such as the energy mix used in your production facilities or supplier-specific data, can be uploaded additionally.
The following table shows which data is required in the different life cycle stages, using the example of a plastic chair.
Materials
Weight (product + components)
materials
Name
Composition
Origin
Supplier properties
chair weight: 5,5 kg
4,5 kg Polypropylene (PP)
>origin: unknown, proxy: China
>50 % recycled
1,0 kg Steel Screws
>origin: Poland
Material Transformation
Process type
Material loss
Energy consumption
Type of energy supply
Additional input (e.g. chemicals)
Location
Injection Molding (PP)
>3,5 % loss rate
>12 kWh electricity
>Italy
Production
Process type
Energy consumption
Energy mix at production facility
Additional input (e.g. chemicals)
Location
Chair Assembly (semi-automated)
>2,5 kWh electricity
>Germany
>100 % renewables
Transport
1. Raw materials - Transformation
2. Transformation - Production
> Distances
> Transport means
PP: China (proxy) - Italy - Germany
>12.000 km ship + 1.500 km truck
>1.800 km truck
Screws: Poland - Germany
>1.500 km truck
Packaging
Weight and type of raw material packaging
Weight and type of component packaging
Weight and type of product packaging
corrugated carton: 1,2 kg
>100 % recycled
Plastic bag: 0,085 kg
Now it's on us: we check your product data, close data gaps, merge data from different sources, and clean it up. Then, we use your static data to replicate the product flow, accounting for non-linear relations and supply chains. This is what we call a virtual BOM.
Typically, your BOM comprises a multitude of components and sub-components. Among these are items that undergo processing or sub-assembly, details not directly included in the BOM. Therefore, we enrich this information to provide a more comprehensive overview.
Life Cycle Impact Assessment is the third step of an LCA - now it's getting interesting!
This phase is about calculating the environmental impact of the products. To do so, we must specify each product's background and foreground system.
Foreground system
The foreground system, also known as the system under study, represents the specific product or process assessed in the LCA. It includes all the activities and stages directly associated with the production, use, and disposal of the product or process.
The foreground system focuses on the unique characteristics and attributes of the product or process, such as material composition, manufacturing processes, distribution channels, and end-of-life scenarios.
Data related to the foreground system are typically collected through LCI phase.
Background system:
The background system refers to the broader context within which the product or process operates.
It encompasses all the upstream activities and inputs necessary to support the foreground system. These activities include raw material production, electricity or heat production for product's assembly.
Background data provides information about the environmental burdens associated with these upstream processes. This data is typically collected from databases, industry reports, scientific literature, and other secondary sources.
Now that we have specified the product system for conducting LCIA, we need to:
Choose background data (emission factors) from databases with high-reliability score
Map foreground- and background data (e.g., product materials and emission factors)
Use the PCF calculation engine to calculate the environmental impact
In most cases, primary supplier data about the environmental impact of purchased goods (e.g., LCAs or PCF studies) are unavailable. In those cases, we use secondary background data from widely used, third party reviewed databases. These include:
Ecoinvent 3.10
EF 3.1
Idemat 2024
Agribalyse
Base Empreinte V23
World of Steel 2022
published EPDs from suppliers
Published LCAs in scientific journals
Each product data point is assigned to an emission factor.
At this stage, our automated LCA engine maps product components to their attributed environmental data.
Now, let's delve into calculating the results.
Below, we'll illustrate this process using the example of a plastic chair in a simplified manner. In practice, this analysis is automated in our LCA engine. Our LCA engine enables the assessment of entire product portfolios and intricate items with numerous components and non-linear supply chains.
Let's go back to our example of the plastic chair.
Weight
5,5 Kg
Composition
81% - PP (of which 50% is recycled)
19% - Steel
Production
Injection molded PP
Loss rate
3,5%
CF (Materials): How to calculate the carbon footprint of materials?
For the recycled material, we apply the CFF method and use an EF from Ecoinvent for the PP.
For the steel screws, the supplier has published an EPD, so we can use supplier specific data here.
The plastic is injection molded, there we have an assumed loss rate of 3,5 %. Therefore, the material carbon footprint (CF) is calculated as follows:
CF (Production):
How to calculate the carbon footprint of production process?
In the next step, the environmental impacts of the production are calculated.
Here we have two steps: First, the PP is injection molded. It means that the plastic granulate is transformed into the desired form.The injection molding process requires 12kWh electricity. The producer reported that they use the Italian grid mix. there is a material loss rate of 3.5 %.
The next step is the chair assembly. This process is done in a semi-automated way in Germany. The amount of electricity required per chair is 2.5 kWh. The producer reported that they renewable electricity.
In most cases, these two phases account for the largest part of the overall PCF. Nevertheless, we still need to calculate the environmental impact of the transport and packaging. In a cradle-to-gate assessment, all upstream transport steps and packagings are considered until the product arrives at the production gate or the warehouse.
In our example, it's crucial to consider the journey of PP granulate from China to Italy via truck and ship, followed by its transit from Italy to Germany by truck.
We adjust for varying material weights due to the loss rate during the injection molding. Meanwhile, the Steel Screws travel from Poland to Germany. Notably, as we rely on the EPD provided by the Steel Screw Supplier, the raw material transport is already factored into the CF, ensuring we avoid duplicating these calculations.
For packaging, we include the product packaging of the final product, which is 1,2 kg corrugated carton (100 % recycled material) and a plastic bag which has a weight of 0.085 kg. The packaging of the steel screws is included in the EF from the supplier EPD and the PP raw material packaging is cut-off in this case.
Adding up all CFs we get the final PCF excluding Safety Margin.
-> Read more about how the Accuracy Score determines the Safety Margin here.