7 Common LCA Mistakes and How to Avoid Them: A Guide for Sustainable Innovation

Life Cycle Assessment (LCA) is an exceptionally powerful tool for any organization committed in bringing sustainability to the surface, where businesses are able to look beyond superficial environmental claims and truly understand the impacts of a product or service, looking at the full range, from cradle-to-grave, or focusing on a narrower, yet solid, range, like cradle-to-gate. As the market pushes for greater environmental responsibility, the demand for robust LCAs and EPDs has never been higher. However, conducting an LCA it’s not a simple “walk in the park”. This powerful methodology is complex, and without a careful approach, one can easily make mistakes that can undermine the credibility of the results.

LCA experts frequently observe common errors that can compromise an assessment's value. For instance, a company might invest millions in re-engineering a product with a new "eco-friendly" material, only to discover that the underlying LCA was flawed. Perhaps it ignored a key toxic emission during the material's processing, or it used data from a different geographical source with a completely different energy grid. The result is a costly investment in a product that isn't actually better for the planet and may even be worse.

In another common scenario, a business might launch a high-profile marketing campaign celebrating a product's low carbon footprint. If the assessment that supports this claim conveniently set its system boundaries to exclude the high-impact use phase or its eventual disposal in a landfill, the company opens itself to public accusations of greenwashing. Such a misstep, once uncovered by competitors or environmental groups, can wear out consumer trust and lead to regulatory scrutiny. Such pitfalls prove that even with the best intentions, a seemingly small oversight at the start of an LCA can cascade into a major business liability.

To help organizations navigate this intricate process and ensure their efforts lead to genuine environmental progress, this article outlines seven of the most frequent mistakes in LCA and, more importantly, how they can be avoided.

1. Defining a Vague or Misleading Functional Unit

The cornerstone of any LCA is the functional unit. It defines the precise function of the product system being studied and provides a reference to which all inputs and outputs are related. A common mistake is to define this unit vaguely, which renders any LCA meaningless when performing a comparison. For instance, comparing the impact of "one kilogram of packaging" is far less insightful than comparing the impact of "packaging required to deliver 1,000 liters of milk safely to the consumer."

To avoid this, practitioners must be specific and concentrate on the actual service the product delivers. Critical questions should be asked: What is the product's primary function? What quantity of that function is being analyzed? Over what period? A well-defined functional unit should always be quantifiable and directly relevant to the product's real-world purpose. Instead of vaguely assessing "a t-shirt," a more robust approach is to define the functional unit as "a cotton t-shirt worn and washed 50 times over a two-year period." This level of detail ensures a fair and accurate comparison. Guidelines, such as the PEFCR (Product Environmental Footprint Category Rule), are common resources at this stage, for they consolidate the best practices for an LCA early stage, such as the Functional Unit.

2. Setting Inconsistent System Boundaries

Essentially, a system boundary determines which life cycle stages and processes are included in the assessment. A frequent and critical error is establishing inconsistent boundaries when comparing different products. This can happen by including the disposal phase for one product but not for its alternative, or accounting for the manufacturing of capital equipment for one process while omitting it for another. Such inconsistencies will inevitably lead to a biased and unreliable comparison, and sometimes even untraceable.

In order to prevent this, one shall clearly define and document the system boundaries from the very beginning of the study. When undertaking a comparative LCA, it is imperative that the boundaries are clearly set for all systems under review, a principle that is reinforced by the ISO 14040 and 14044 standards.

Organizations must also maintain transparency about any processes that are excluded, followed by a clear statement as to why their omission is not significant to the overall results. In the end, the criteria for conducting an LCA should follow a transversal approach to every study.

3. Using Inappropriate or Outdated Data

The quality and credibility of LCA results are directly dependent on the quality of the data used. A significant mistake is to rely on generic, outdated, or geographically irrelevant data, which can dramatically skew the findings. For example, using a global average for the electricity mix to analyze a product manufactured in a country with a high percentage of renewable energy will fail to capture the product's actual, more favorable impact profile. In the same way, if an average European mix is to be considered for a product’s manufacturing scenario in a country that relies heavily on coal for its electricity generation, it will provide a worse environmental profile than what it represents.

Meticulously documenting all data sources and assumptions is non-negotiable. To ensure that accurate data is used, practitioners should prioritize the use of high-quality, specific data, which implies collecting primary data directly from the organization's operations whenever feasible. When secondary data is necessary, it is crucial to rely on reputable and professionally managed LCA databases, such as ecoinvent or GaBi. Furthermore, the data must be verified as recent and geographically appropriate for the specific context.

4. Ignoring the Use and End-of-Life Phases

It is tempting for companies to focus heavily on the manufacturing stage and its close value chain nodes, where they have the most operational control and direct access to data. However, neglecting the other stages is a serious oversight. For many products, the most significant environmental impacts occur during the use phase, such as the electricity consumption of an electronic device over its lifetime, or at the end-of-life, like the methane emissions from landfilling.

A truly comprehensive assessment is conducted using a cradle-to-grave or cradle-to-cradle approach. Modeling the use phase based on realistic user behavior can be tricky, since usually there is no way of tracking consumer habits, which can also be quite volatile. For the end-of-life stage, the analysis should consider all probable scenarios, including recycling, incineration, and landfilling, weighted according to the actual practices and available infrastructure in the relevant region.

5. Misinterpreting Results and Ignoring Uncertainty

An LCA generates a wealth (and many times overwhelming amount) of data across numerous impact categories, like Global Warming Potential and Water Consumption. A prevalent mistake is to focus on a single impact category and ignore the others. This can lead to "burden shifting," where solving one environmental problem inadvertently creates one or many. Not to mention that all LCA results contain a degree of uncertainty, and presenting them as absolute outcomes is both inaccurate and misleading

A more responsible approach involves analyzing the results across a broad range of relevant impact categories. Normalization and weighting are methodologies that can be used, with caution and full transparency, to better understand the relative significance of different impacts. Another way of testing fluctuations is by conducting a sensitivity and uncertainty analysis, proving the robustness of the conclusions. Communicating findings as ranges or with confidence intervals reflects the inherent uncertainty in the model, in a truly transparent and honest way.

6. Forgoing a Critical Review

Much like any formal scientific study, an LCA can be subject to unintentional bias or errors, where failing to have the LCA critically reviewed by an independent third party can severely damage its credibility. This is especially true if the results are intended for public disclosure or to support comparative assertions, where scrutiny will be highest.

To uphold the integrity of the work, adherence to the ISO 14044 standard is essential, as it explicitly requires a critical review for any publicly disclosed, comparative LCA. Even for internal studies, commissioning a review by a qualified, independent expert or panel is a best practice that significantly strengthens the quality and reliability of the final conclusions.

7. Poor Communication and Lack of Transparency

Communicating the results is the final stage of an LCA, where diligent work can be undone. Presenting findings without proper context, using inaccessible jargon, or failing to disclose key assumptions can easily lead to misinterpretation and mistrust. An LCA report that is not understood or trusted serves no constructive purpose. That is why an LCA is built on a framework that allows a practitioner to return to any previous stage if a finding is inconsistent downstream in the methodology, as it is stated in ISO 14040, turning it into an interactive and iterative process.

To avoid this, communication strategies must be tailored to the intended audience. For instance, a detailed, technical report is appropriate for an expert eye, but an executive summary or infographic brochure is far more effective for the general public or non-technical stakeholders. Regardless of the format, the guiding principle must be transparency, whereas being explicit about methodology, assumptions, limitations, and data sources is critical to prevent misunderstanding.

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Avoiding these common mistakes requires expertise, diligence, and a significant investment of time. For organizations looking to conduct credible, impactful, and decision-useful LCAs without the steep learning curve, joining forces with a specialized partner is the most effective path forward.

ZeroPact provides direct access to a team of seasoned LCA professionals who ensure every step of the process is robust, compliant with ISO standards, and strategically aligned with your business goals. The gains are instant: accelerated project timelines, enhanced credibility through expert third-party analysis, and the translation of complex environmental data into clear, actionable insights. With ZeroPact, your organization can move beyond simple compliance to leverage LCA as a powerful tool for sustainable innovation, risk management, and building a stronger, more transparent brand.