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How to read an EPD | One Click LCA

Written by Melina Zacharia | Sep 11 2024

This guide helps you understand what to look for in an EPD document and how to properly compare different EPDs.

An environmental product declaration (EPD) is a document that transparently reports the environmental impact of a product or material throughout its lifecycle. EPDs support carbon emission reduction targets by making it possible to compare the impacts of different materials and products in order to select the most sustainable option for buildings or infrastructure. 

  • Manufacturers are able to measure, analyze, and optimize the impact of their products and market their carbon transparency.
  • Sustainability managers, engineers, and product designers use EPDs to help them choose the most sustainable material for their products.

An EPD is usually valid for five years, and is generated according to the relevant standards. Construction EPDs are based on the ISO 14040/14044, ISO 14025, EN 15804 or ISO 21930 standards.

EPDs are standardized documents that provide detailed information about the environmental impacts of a product or material. These impacts are assessed according to specific Product Category Rules (PCRs), which ensure consistency and comparability across similar products. EPDs are designed to be transparent and do not include proprietary information, focusing instead on disclosing environmental data that is essential for stakeholders, including consumers, regulators, and industry professionals.

Different types of EPDs

EPDs can differ based on their application and verification.

Third-party verified EPD — for any purpose

Third-party verified EPDs are the most widely recognized type of EPD,  they are required by many regulations and certification schemes and accepted by almost all. As well as being third-party verified in compliance with ISO 14025, they are published by an EPD program operator and can be used for almost any purpose. A third-party verified EPD is valid for 5 years unless the parameters change. If there are significant changes in key parameters—such as raw materials used, manufacturing processes, supply chains, or energy consumption—the EPD may no longer reflect the product's true environmental impact. If these parameters change during the 5-year period, the EPD would need to be updated and potentially re-verified to ensure it remains accurate. This is to prevent outdated or misleading information from being used after significant changes to the product.

Some EPD program operators offer Variant EPDs that are based on an already published third-party verified EPD. Variant EPDs must be similar to the third-party verified EPD they’re based on; they must be manufactured using a similar process, from similar raw materials, and for a similar function. This type is also in compliance with ISO 14025.

Project EPDs — for contracts & tenders

Project EPDs are created for a specific project or contract. They are non-published documents verified internally by designated qualified personnel or through a company’s established quality management processes, rather than being reviewed by external program operators or made publicly available. Project EPDs are crucial for companies aiming to manage the environmental impacts of specific projects or tendering processes internally. Project EPDs facilitate the scaling of EPD adoption without the expenses associated with third-party verification for each declaration. Although Project EPDs comply with ISO 14025, they are distinctly marked as “Internally Verified” to clarify their verification status. Some program operators assign shorter validity for Project EPDs.

Self-declared environmental claims — other transparency requirements

A self-declared environmental claim, according to ISO 14021,  is an environmental statement made by a company about its product without third-party certification. The claim must be truthful, verifiable, and not misleading, with evidence available to support it to ensure transparency, consistency, and accuracy in environmental marketing claims.

System EPDs — for EPDs at scale

Automatically generated EPDs for a large number of products which are generated by a system on-demand, meaning the individual documents themselves are not subject to direct verification, but the process or system generating them has been verified. The verification is done on the system that produces the EPDs, ensuring that it meets certain criteria. However, this means the final document itself is not necessarily individually checked or verified. The need for scalable EPD solutions, such as System EPDs, has arisen due to the growing demand for environmental documentation in the construction industry. However, system EPD raise concerns around transparency since these automated systems don’t always provide the same level of scrutiny as traditional, manual verification processes. These System EPDs are widely used in building LCAs for certain product categories, such as ready-mix concrete.

Are they considered third-party verified EPDs? 

For an EPD to qualify as third-party verified, the verification process must clearly indicate that the final EPD document has been reviewed and approved by an independent verifier. System EPDs don’t always meet this criterion, which could be an issue for certain certifications or standards that require explicit third-party verification. To ensure your EPD is third-party verified make sure to always check that the verification statement clearly mentions that the final document has been viewed and verified by a verifier. In traditional third-party verified EPDs, a third-party verifier confirms that the life-cycle assessment (LCA) and the EPD document conform to standards (ISO 14025, EN 15804). 

Always note the verification statement. In System EPDs, only the generation process or method will be noted as verified, as shown in the example below:


How to read an EPD

EPDs provide valuable insights about a product’s environmental performance at a glance. However, EPDs may vary in appearance depending on the Product Category Rules (PCRs) they follow and the program operator that publishes them.

An EPD covers the following information:
  1. General information: Includes details about the manufacturer, the product, the reference standards, and the EPD scope.
  2. Product lifecycle information: Provides details on the lifecycle modules covered by the EPD.
  3. Life-cycle assessment (LCA) methodology: Explains the methodology used to assess the life cycle.
  4. LCA background information: Includes assessment of data quality and interpretation of results.
  5. Environmental impact data: Presents data on the environmental impacts identified in the assessment.
  6. Verification statement: Contains the statement verifying the accuracy and validity of the EPD data.

To effectively compare different EPDs, or to go through the most important information of an EPD, you should focus on these five key points:

  • Reference standards used for the EPD

The reference standards used for the EPD are the official guidelines and scientific methods followed to calculate and report the environmental impacts. These standards ensure that the EPD is produced using reliable, recognized methodologies, so the data is comparable across similar products and is accepted in the industry. Construction EPDs are based on the ISO 14040/14044, ISO 14025, EN 15804 or ISO 21930 standards. In the example EPD below, you can find this information under EPD Standards, Scope and Verification:

  • Period of validity

The period of validity refers to the time frame during which the EPD remains accurate and relevant. EPDs are based on data that can change over time due to shifts in manufacturing processes, energy sources, or supply chains. This period ensures that the environmental impact data provided is up-to-date and reliable for a specific duration, 5 years for third-party verified EPDs. After this period, the EPD should be reviewed or updated to reflect any changes. This example EPD below, has validity for 5 years:

  • Verification

It's important to ensure that an EPD is third-party verified. This means an independent organization has reviewed the data and processes used in the EPD to confirm its accuracy. Third-party verification adds credibility to the EPD, showing that the environmental impacts, such as carbon emissions, are calculated properly and are based on reliable information. 

  • The environmental data summary

The environmental data summary provides key information about the product’s environmental impact. The main components to look out for include:

  1. GWP-total (global warming potential), A1-A3 (kg CO₂e): This measures the product's total carbon footprint, showing how much it contributes to climate change. It accounts for all greenhouse gas emissions from stages A1 to A3 (raw material extraction, transportation, and manufacturing).
  2. GWP-fossil, A1-A3 (kg CO₂e): This focuses specifically on emissions from burning fossil fuels during production. It's a more detailed look at how much fossil energy is consumed and how much CO₂ is emitted as a result.

  • Declared unit 

You can find the the declared unit under product description. Declared unit is the reference point for measuring environmental impact. It's like saying "calories per serving" when describing food nutrition. For construction products, this might be measured in terms of weight (e.g., kilograms of concrete) or volume (e.g., cubic meters of a material). The declared unit standardizes the environmental data so that the impacts, such as emissions or energy use, are compared on the same basis across different products.

By checking these elements, you ensure the EPD is current and that you're examining the intended product. This approach helps you understand  the characteristics for comparison, including type, impact, and unit. 

How to compare different EPDs

Manufacturers, architects, and engineers often need to compare EPDs when selecting suppliers or choosing products with the lowest environmental impact for their projects. To make an informed decision, it's essential to focus on key factors that reveal the most important details of their environmental performance. These factors will help ensure a fair and accurate comparison between EPDs:

1. Functional unit 

Products should be compared based on the same functional unit to ensure that their environmental impacts are measured equivalently. If the functional units differ, the comparison will be skewed.

2. Scope of the EPD

EPDs can have different life cycle stages:

  • Cradle-to-gate: Covers extraction of raw materials to manufacturing.
  • Cradle-to-grave: Covers the entire lifecycle, from extraction to disposal.
  • Cradle-to-cradle: Includes recycling at the end of life.

Ensure the products being compared use the same life cycle stages in their EPDs to avoid inconsistencies.

3. System boundaries

Understand what is included in each EPD. Some may cover additional or fewer processes, such as transportation, energy use in operation, or end-of-life disposal. The system boundary should be consistent to ensure all aspects of the product’s lifecycle are accounted for similarly.

4. Environmental impact categories

The environmental impact categories are the same and comparable. Ensure that both products report on the same categories to make meaningful comparisons. Common categories include:

  • Global Warming Potential (GWP)
  • Ozone Depletion Potential (ODP)
  • Acidification Potential
  • Eutrophication Potential
  • Photochemical Ozone Creation Potential

5. Data quality and source

Verify the quality and sources of data used in the EPD. Primary data (from actual manufacturing processes) is generally more reliable than secondary data (from databases or literature). Products with well-documented, high-quality data are easier to compare accurately. You can find this information in the 'LCA background information' section.

6. Geographical and temporal differences

Geography can influence the environmental impact of a product (e.g., energy mix in manufacturing locations or transportation distances). Similarly, temporal differences (the year the data was collected) matter, as technologies and regulations change over time. Ensure both products are analyzed in the same geographic context and time period.

7. Assumptions and allocation methods

Some EPDs make assumptions about things like energy use, transportation distances, or recycling rates. Be sure that similar assumptions or allocation methods are used when comparing products. You can find this information in the 'LCA background information' section.

8. Certification and verification

Ensure that both EPDs are verified by an independent third party to ensure the data is credible and consistent with international standards (e.g., ISO 14025, EN 15804).

9. Product lifespan

Some products might have different expected lifespans. Comparing them on a per-year basis (e.g., GWP over 50 years of service) can provide a clearer picture, especially if one product lasts significantly longer. Find this information the product description.

10. Material composition and recyclability

Consider the materials used and their potential for recycling or reuse. A product with a high environmental impact during manufacturing might offset this by being highly recyclable or having a long lifespan.

By focusing on these factors when comparing different EPDs, you can ensure you’re comparing products in a way that reflects their true environmental performance, helping you make more informed and fair eco-friendly choices.

How can One Click LCA help you with your EPD journey?

1. Create & publish EPDs for your products

One Click LCA's EPD Generator tool offers an end-to-end solution for manufacturers who need to create environmental product declarations (EPDs) compliant with global ISO and EN standards. With this tool, users can perform unlimited life-cycle assessments (LCAs) and generate EPDs for any product category. Additionally, the EPD Generator provides the flexibility to create customer-specific private EPDs and TM65-compliant calculations. 

2. Evaluate your EPD & optimize your product with EPD Usage Analytics

EPDs can be crucial tools for manufacturers to assess and optimize a products' environmental performance. One Click LCA understands that the EPD journey doesn't end with the creation and publication of EPDs. Being able to see how your EPD is performing and the interest it generates, can help you make data-driven decisions to enhance your product strategy and market positioning. 

To maximize these benefits, manufacturers can leverage advanced One Click LCA tools like EPD Usage Analytics, which provides detailed product insights, global performance tracking, and an interactive dashboard. This tool allows manufacturers to analyze usage statistics, identify top-performing products, and anticipate EPD expirations, enabling informed strategic decisions that align with market demands for sustainable construction materials and contribute to broader sustainability goals in the industry.