Choosing the scope and boundary for a product carbon footprint assessment is crucial for accurately measuring carbon emissions. A correct scope allows to obtain useful results for companies aiming to make informed decisions about the products they design, manufacture, sell, purchase, or use. This guide helps you understand the main considerations such as life cycle boundaries, data requirements, and how business goals impact your decisions when calculating your product's carbon footprint.

In this guide:

What is the 'Scope' in a product carbon footprint assessment?

A scope defines the limits of your carbon footprint, aiming to specify exactly what is being measured. This includes selecting the product, its measurement unit, and the greenhouse gasses to be studied.

Most standards require inclusion of greenhouse gasses CO2, CH4, N2O, SF6, PFCs, and HFCs. In Cozero, all results are calculated in carbon dioxide equivalents, measuring the impact of all greenhouse gasses. This simplifies the comparison and aggregation of the different greenhouse gasses by converting their varying impacts on global warming into a single, standardized unit. Therefore, your main decision is to decide which products to study.

What is the ‘Boundary’ in a product carbon footprint assessment?

A boundary defines which parts of a product's life cycle you will include, and which activities will fall within them for the carbon footprint assessment. Establishing a relevant boundary will allow consistent comparability for year on year accounting.

The boundary selection largely depends on the goal of the assessment and how you intend to use the results. For example, if you wanted to share data of the product’s manufacturing impacts to your customers, you could choose a boundary covering raw materials acquisition and manufacturing. If you wanted to measure the product’s entire impact throughout its lifecycle, you could expand the boundary to also cover the product’s transportation to customers, emissions from the energy needed for its use, and its disposal at the end of its life.

Together, the scope and boundary specify exactly what your product carbon footprint measures. Clear definitions for both enhance transparency, facilitate comparison of different products, and support informed product development decisions.

How to choose which products to assess?

Choosing the products for a carbon footprint assessment ultimately depends on your sustainability goals, available data, and resources. Here are some recommendations:

Focus on Key Products:
- Products generating most of your revenue.
- Products you manufacture the most.
- Products with readily available data.
Leverage Corporate Carbon Footprint Data:
- Select products with the highest impact on your overall emissions.
Keep your business goals in mind:

Which products are sold to your most important customers?

If important customers request carbon footprint data for their own calculations, prioritize these products. Providing carbon footprint data for products you sell can offer a significant competitive advantage and improve customer relations, especially if your customers have set climate targets of their own.

Where can you have the most impact to reduce emissions?

If you want to create more sustainable products, the first goal is to measure which actions can create the most impact to reduce emissions. You might have already identified that some products could be manufactured by using recycled or locally procured materials, or manufactured using materials with a lower carbon intensity. Some products could be recycled at the end of their life cycle. In these cases, focusing on such products is often the best course of action.

Assessing multiple products with one product carbon footprint

If you produce similar products with minor differences in composition or production processes, there's the option to calculate:

an average product carbon footprint using data of many products within a group,
or a representative footprint for one product seen as the best representation of the group.

When using averages, weight all data based on produced quantities. For a representative product, it's often recommended to choose the assumed "worst-case product" generating the highest emissions among the group.

These approaches are, however, less accurate than single-product focused footprints and have a lower data quality. They also don’t provide the granularity of assessing individual product components for more targeted transformation. Different raw materials, production processes, or product uses can change the climate impacts of products drastically, and therefore the calculated footprint might not accurately represent all the products. For this reason, it is important to only include very similar products with the same main material composition and production processes. It is also important that you communicate the scope of such footprints to stakeholders transparently.

An example:

A textile company manufactures multiple types of clothing, but has limited time and resources to calculate individual product carbon footprints. The company makes multiple different colors and sizes of each clothing type, but the main raw materials and production processes for products within the same category are the same.

The company decides to create one average footprint for each product category to represent all colors and sizes, and starts with their most sold product category, cotton t-shirts. The company decides to collect data for each product size, and calculate the product footprint based on the weighted averages for each input, using sold quantities for each size.

How to set the product carbon footprint boundary?

Once you have selected the products you want to assess, the next step is to assess what your product carbon footprint should include. This should include the following considerations:

1. Select a life cycle boundary based on the purpose of the assessment

Not familiar with life cycle boundaries? Read more on our article on life cycle assessment boundaries

The first step to define your boundary is to define why you are conducting the carbon footprint assessment. Determining the “why” helps you decide which activities the assessment should reflect, and what should be prioritized to make the most out of the obtained results.

In this section, we present you with example scenarios to help you identify key considerations.

Activities included in a full life cycle boundary. The selection of included activities depends on the desired boundary and purpose of the analysis.

Scenario 1: You want to reduce production emissions or your customers are requesting you provide PCF data for their own carbon footprint calculations.

Customer data requests are one of the main drivers for manufacturing companies’ need for product carbon footprint data. In this case, you would most likely want to focus on the impacts of raw materials and the emissions from your own production processes. A cradle-to-gate boundary, which covers raw material acquisition, production, and packaging, is often the most sensible choice. Understanding emissions from these activities can also help you make informed choices about the types of raw materials you procure, or how to start optimizing your manufacturing processes.

Scenario 2: You want to reduce emissions throughout a product’s lifetime or inform your customers on the emissions created by the use and disposal of the product.

Does your product require energy to be used by consumers, either directly like vehicles or machinery, or indirectly like clothes that require washing during use? This often means that the use by consumers creates an important source of emissions for the product. To reduce these emissions, you could find ways to improve the product’s energy efficiency, use materials that require less washing, or educate your customers on the most climate-friendly way to use your products. Additionally, you might want to explore the impacts from material disposal once the product is disposed of. This allows you to consider choices of used materials to increase the product’s recyclability, and inform your customers on the best ways to dispose of the product.

Before taking action, it’s important to assess the impact you can create. Therefore, accounting for the full life cycle of the product with a cradle-to-grave or cradle-to-cradle approach is the best way to identify which emissions hotspots you should address.

Scenario 3: You want to compare the climate performance of different products.

Using product carbon footprint data for product comparisons brings an added layer of complexity to the analysis. Instead of the scope and boundary of one product, you need to make sure the scope and boundary are equal and comparable for both. This typically means the products need to fill the same function and have all the same types of emission-generating activities included.

Not familiar with definitions like functional units or not sure how to choose the product measurement unit? Read more about how to set up your products in Cozero.

For example, if you compare two laundry detergents, one might have a lower cradle-to-gate footprint per kg of product, but might require a larger quantity to be used during washing, or a higher temperature for the washing programme. These factors could make the product’s total footprint higher. This is why defining a matching functional unit and including all life cycle steps in the analysis is important for understanding the products’ full impacts. Comparisons of digital products and physical products that fill the same function can be even more complex, as the products are created and used in very different ways. Whatever the type of products you want to compare, it’s important you approach the comparison without aiming to make one product seem better. It is important your decisions and communications are driven by accurate data.

It is important to note that in order to avoid greenwashing, public statements of one product’s better performance over another need to be backed up by public reporting of the product carbon footprint assessment. This needs to include a detailed explanation of the methodology used for both assessments.

We also recommend having the assessment evaluated by a third party verifier to ensure you are communicating only accurate information. You can always reach out to Cozero for support in finding a verification partner.

2. Prioritize the most significant activities

We recommend every product carbon footprint to cover at least the cradle-to-gate boundary. However, if your product continues to use energy in consumer use, needs long-distance transportation, or contains hard-to-recycle materials, downstream impacts should also be considered.

When selecting life cycle stages, map out and select relevant activities and processes at each stage. Aim to include every activity the product undergoes, especially within your own production processes, where data availability is highest. Product carbon footprints should only include activities specific to the product. For example, energy consumed by the production line should be included, but not electricity use of overhead lighting or office facilities. These can be included if they are deemed important for overall business goals, but should be documented and reported transparently.

When to exclude materials or activities:

Most PCF standards allow minor exclusions of raw material data and downstream activities. In general, no exclusion should be larger than 1% of the product’s footprint within the life cycle phase. For example, if one raw material that you can’t connect to a fitting emission factor weighs less than 1% of the total weight, you can consider excluding this material from the calculation. Before making exclusions without emissions data, you should, however, also assess the emissions potential of the component. If despite the small weight it includes a complex or energy-intensive production process, or materials that need to be mined or processed excessively, we recommend making an estimate of the impact rather than completely excluding it.

Tip: Estimations, such as using a similar activity or material as a proxy to estimate the emissions can be an excellent way of covering data gaps for minor activities without using too many resources to complete the carbon footprint. Whenever you do make exclusions, you should document and report them well.

3. Make decisions based on data availability

It’s important to evaluate the availability and accuracy of data. Reliable data is crucial for an accurate assessment. If data for a certain life cycle stage or process is lacking, you might need to adjust your boundary or select an entirely different product for which you can collect the necessary data. Alternatively, if such an activity is estimated to be minor, you could consider ways to reflect its emissions with a similar activity for which you can obtain data. Often, creating a carbon footprint is a process of balancing accuracy with available resources, and making the correct decisions can help you achieve both.

Product footprints are more focused than organizational footprints, which is why their data requirements are often higher. If your customers are requesting you to follow a specific standard or if your sector or national regulatory demands set data quality standards, it is important to follow them. We always recommend using activity data at least for the cradle-to-gate boundary, such as the actual weights of materials, transport distances, and energy consumption, over data points like spend that are often used to estimate organizational emissions. For downstream activities, a good way to collect data is often to make assumptions based on your product and your industry practices. You could for example review any product instructions on the recommended use of the product that you share with consumers. This can give you a basis for assumptions on how customers use or dispose of your product. Another way is to look for industry benchmarks to establish assumptions for the activities.

An example

The textile company has received requests from their customers to share data on their purchased products’ footprints to be able to use in their scope 3 accounting. Therefore, they decide to include life cycle steps Raw material acquisition, Production, and Packaging, to be able to communicate cradle-to-gate data. The company decides to include all production processes, including product coloring, that is identified to require a significant amount of energy. However, the coloring agent used as the raw material is identified to only make up 0.01 % of the product composition. The company also uses a set of different coloring agents from a multitude of suppliers, making data collection difficult. Therefore, the company decides to exclude the coloring agent from the assessment.

However, the company also manufactures t-shirts using polyester, and would eventually like to understand the differences in climate impacts between the two fabric types. They know the products go through the same manufacturing process, but use different materials. They review the care instructions for the products, and identify the recommended washing and drying instructions are different. To ensure they can accurately compare the two product categories in the future, the company decides to calculate full life cycle impacts for the cotton t-shirts. Therefore, they include life cycle steps Distribution and storage, Usage, and End-of-life and turn their cradle-to-gate boundary to a cradle-to-grave boundary.

Need Further Assistance? The Cozero team is happy to help!

If you have more questions about which activities to include in your product carbon footprint or have questions about boundary setting, please get in touch with your Customer Success Manager. Our team of climate experts is happy to support you in finding the best option for you.

Continue with our second part of the PCF series for a step-by-step guide on how to set up your Product Carbon Footprint (PCF) in the Cozero software.