EPDs and LCAs Are Not Interchangeable — and Treating Them That Way Creates Risk

Environmental Product Declarations (EPDs) and life cycle assessments (LCAs) both show up regularly in conversations about embodied carbon and sustainability requirements for concrete.

While the two are closely related, they serve different purposes — and treating them as interchangeable can lead to misinterpretation, misplaced confidence, and real risk in specifications, procurement, and reporting.

LCA: An Analytical Method Designed to Answer a Specific Question

An LCA is a systematic analytical method used to quantify the environmental impacts of a product or process across defined stages of its life cycle. The scope of an LCA is established through explicit choices about system boundaries, data sources, and scenarios.

In concrete applications, an LCA might include impacts associated with raw material extraction, transportation, and concrete manufacturing — but it also might include placement, use-phase assumptions, and end-of-life or disposal scenarios. Which stages are included depends entirely on the goal of the analysis — whether that goal is exploratory decision-making, scenario evaluation, or alignment with a standardized disclosure such as an EPD.

This flexibility is a defining feature of LCAs. Because an LCA is designed to answer a specific question, its scope, boundaries, and assumptions can be adjusted to explore different scenarios or trade-offs. Depending on the goal, an LCA may be used to compare design options, evaluate sourcing strategies, or test how changes in performance requirements affect environmental outcomes. LCAs are not limited to embodied carbon alone and can assess multiple environmental indicators as defined by the study design.

In other words, LCAs are designed for exploration, not disclosure.

Because LCAs are goal-driven and assumption-dependent, they are most often used internally by engineers, sustainability teams, and consultants to support analysis, comparison, and decision-making — not standardized disclosure. In concrete production, this typically means producers do not need to work directly with LCAs unless they choose to develop EPDs internally or undertake specific analytical studies beyond disclosure requirements.

EPD: A Standardized Disclosure Built from an LCA

An EPD is a standardized disclosure document derived from an underlying LCA. Rather than answering a specific analytical question, an EPD reports selected LCA results in a prescribed format so that environmental information can be disclosed consistently across products with similar functions.

In concrete applications, EPDs are developed in accordance with product category rules (PCRs) that define elements such as declared units, system boundaries, required impact categories, and calculation methods. These rules constrain how the underlying analysis is performed and how results are reported, ensuring that concrete EPDs are developed within a common methodological framework.

This standardization is intentional. By fixing key assumptions and reporting requirements, EPDs limit analytical flexibility in exchange for consistency and transparency. An EPD is not designed to explore scenarios or test alternatives; it is designed to communicate environmental impact indicators for a defined product under defined rules.

That constraint is what makes EPDs usable as disclosure documents.

Because EPDs are disclosure tools, they are most often used to support documentation, procurement, compliance, and reporting requirements. Verification confirms that the declaration follows the applicable rules, not that the product is optimized for a particular project or that the results can be applied beyond the EPD’s defined scope.

The Difference That Gets People Into Trouble

The confusion between LCAs and EPDs usually doesn’t come from missing information — it comes from assuming the tools serve the same purpose because they are numerically related. LCAs generate results to answer a question. EPDs disclose a subset of those results under fixed rules.

When that distinction is ignored, environmental data is asked to do work it was never designed to do — the issue is not the data itself, but the expectations placed on it.

How LCA–EPD Confusion Shows Up — and Why It Creates Risk

The confusion becomes visible when environmental data moves from analysis into specifications, bids, or reporting workflows — and the distinction between analysis and disclosure gets blurred.

In practice, this shows up in two recurring ways:

• EPDs are treated as project-specific predictors, despite being standardized disclosures.
• Internal LCAs are treated as compliance-ready comparisons, despite being assumption-driven analyses.

In concrete projects, these misinterpretations translate into practical risk: misaligned specifications, disputed comparisons during bidding, over- or under-commitment to carbon targets, and credibility issues when reported numbers don’t hold up under scrutiny. The issue isn’t the math — it’s role confusion. Each tool is reliable within its intended use, and risky when asked to do work it was never designed to do.

How LCAs and EPDs Should Be Used Together

Every EPD is based on an LCA, but not every LCA becomes an EPD. In concrete practice, LCAs are typically used internally to explore options and identify environmental “hotspots” — such as cement content, SCM availability, transport distances, or energy use — under assumptions tailored to a specific question. When a producer chooses to publish an EPD, that analysis must be aligned to the applicable PCRs, documented, and verified so results can be disclosed consistently.

This transition from analysis to disclosure is where misunderstandings often occur. An internal LCA may include scenario ranges, sensitivity testing, or exploratory assumptions. A publishable concrete EPD, by contrast, reports a defined product under defined rules, even when those rules require conservative or standardized assumptions. Both tools are valuable, but only when they are used for the purposes they were designed to serve.

Practical Takeaway: Match the Tool to the Question

LCAs and EPDs serve different roles in concrete sustainability work. LCAs are analytical tools, used to explore options, test assumptions, and understand how changes in materials, sourcing, or design affect environmental outcomes. EPDs are disclosure tools, used to report selected results under standardized rules so environmental information can be documented and interpreted consistently.

Problems arise when that distinction is ignored. When teams are clear about whether they are answering an analytical question or fulfilling a disclosure requirement, the choice of tool — and the interpretation of results — becomes straightforward. That clarity is what allows environmental data to support credible decisions, rather than create confusion or risk.

Have questions? Want to learn more? Contact Climate Earth.

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