|Executive Summary - BIFMA Chair LCA Study|
Manufacturers, suppliers, architects, and designers face increasing pressure today to provide information about the environmental impact of the products they manufacture and specify. Yet understanding a product’s environmental properties is not as straightforward as one might think, as many issues factor into this evaluation.
Raw material production and the energy used to manufacture a product play a role in its environmental impact, as do other factors such as its transportation to market, how it interacts with its environment while in use, and how the product will be disposed of at end of life.
As the transparency trend gains momentum, more manufacturers are developing and releasing public documentation including Environmental Product Declarations (EPDs). While the use of these documents attempt to aid consumer understanding of a product’s lifecycle and its potential environmental impact, the end-user must be cautioned against making an apples-to-apples comparison of products made by different companies.
The Business & Institutional Furniture Manufacturers Association (BIFMA) recently commissioned an independent, third party evaluation of the potential for differing outcomes in final life cycle assessment (LCA) results based on reasonable assumptions that an LCA practitioner may make during an assessment. We determined that the variability within a single product could be significant based on key, but perfectly reasonable, variables employed by the practitioner. Consequently, comparing similar products from different manufacturers is not recommended. Users of EPD data should be aware of the assumptions used in the study to get the most benefit.
Defining the Process
Product Category Rules (PCRs) guide the LCA practitioner in how to perform an evaluation of a product’s environmental impacts, and are specific to that product. For example, rules for evaluating the manufacture of a chair will differ from those for evaluating a desk. The PCR defines the information that should be included in a life-cycle assessment, helps minimize the practitioner’s choice of assumptions and datasets, and defines the way the final data will be presented to the public. This protocol creates clear boundaries, much in the same way that a deed defines a parcel of land.
An LCA of a product or building enables manufacturers, architects and designers to estimate the product’s potential contributions to global warming, ozone depletion, water pollution, ozone creation and energy and water use at each manufacturing stage. These stages include the production of raw materials, materials transportation during manufacturing (including delivery to the marketplace), the manufacture and assembly of the product’s components, its use in the marketplace and its disposal, reuse or recycling at the end of its life.
Once a life-cycle assessment is performed using the product category rules and a third-party verifies the results, the manufacturer can prepare a formal statement, known as an Environmental Product Declaration (EPD).
The EPD provides manufacturers, architects and designers a public disclosure mechanism of a product’s potential environmental impact. This declaration, supported by a life-cycle assessment generated on a reliable set of product category rules, creates a level of transparency comparable to nutrition labels in the food industry. And similar to the call for food labeling regarding nutrition information, there is a growing demand for EPDs in the built environment. P
A great deal of time and effort has gone into compiling the data and assessment protocols for an accurate EPD. However, one challenge remains: customers assume, not unreasonably, that they can compare results from different companies. Although an LCA is a useful tool for identifying environmental hotspots in a product lifecycle and for internal evaluation of materials and designs, it is less beneficial when comparing products across different companies. This is because it is possible to use the same product category rules for two almost-identical products yet generate different results in the final declaration simply by choosing to use a different, but equally valid, dataset.
Fortunately, the world is moving from a collection of competing single-attribute standards to a more comprehensive life-cycle based approach. But it’s important to acknowledge that different datasets and varying levels of data quality, coupled with LCA practitioner assumptions, can produce quite different final results, even for the same product. It’s important to stress that this does not make the LCA a poor tool. Rather, it is still a very powerful instrument for understanding environmental impacts from a manufacturer’s perspective. Still, it is less useful in directly comparing products between different companies, due to the unique ways in which each company applies the science.
BIFMA has developed a state-of-the-art series of Product Category Rules for manufacturers of seating and commercial storage products. To evaluate the uncertainty in the outputs of the LCA based on specific ways actual LCA practitioners resolve assumptions and data quality, we engaged the Institute for Environmental Research and Education (IERE) and Industrial Ecology Consultants, third party LCA experts, to test the potential for varying results on one product using the BIFMA/NSF Seating PCR. We wanted to identify potential sources of variability within a single set of guidelines and assess their effects on the resulting EPD.
To achieve this goal, the research team created a hypothetical model of a metal office side chair composed of materials common to this type of product, and analyzed it using the guidelines found in the BIFMA PCR for Seating. The team employed two different prominent life-cycle assessment software products to analyze the chair with the assumption that it would be in use for 10 years. They performed the analysis using software “package A” with proprietary industry average data, and “package B” using Ecoinvent data.
The team made two immediate observations. First, the two software/data packages produced results that were reasonably comparable. However, the differences tended to be greater than the 10 percent threshold set by many PCRs to revise an Environmental Product Declaration when a product changes. Second, each software/data package produced substantial differences between the most and least conservative scenarios. These differences could vary by a factor of two or three (and up to 15 for one environmental impact), due primarily to the use of different data sets and calculation approaches.
Most importantly, the study team determined that it’s not possible to declare with absolute certainty that one result negates the other. Even though PCRs attempt to eliminate potential variations in results, enough ambiguity existed within the guidelines, data and calculation methods to require a practitioner to rely on his or her professional judgment. This in turn can skew the results and create two different yet equally legitimate results for the same chair.
However detailed and specific a PCR’s requirements might be, there will be instances of ambiguity in which a practitioner must rely on professional judgment to determine the best modeling approach. Furthermore, practical constraints such as data availability may further limit the practitioner’s modeling options.
How should product specifiers and end users interpret and utilize the results of this study?
We believe this study presents BIFMA with the opportunity to educate our members and their customers of the potential variations in environmental product declaration results, and further, to advocate for improvements in the data and evaluation process. We feel it is our role to assume a leadership position in opening up this issue to scrutiny and analysis.
Although life-cycle assessments can be a strong mechanism for supporting sustainable buildings and products, it’s important to remember that these evaluation tools require further refinement and improvement. As this fine-tuning process continues at a steady pace, we believe the industry should continue to use product category rules when conducting life-cycle assessments, keeping in mind that different software/data packages can and will deliver different results.
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