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Cradle-to-Grave Life-Cycle Assessment of Wooden Pallet Production in the United States Sevda Alanya-Rosenbaum, Postdoctoral Fellow Richard D. Bergman, Supervisory Research Forest Products Technologist USDA Forest Service, Forest Products Laboratory, Madison, Wisconsin, USA Executive Summary Study Goals The primary goal of this study was to quantify the environmental impacts of the wooden pallet manufacturing and recycling industry in the United States. For this purpose, an industry-average cradle-to-grave life-cycle inventory (LCI) was developed and a cradle-to-grave life-cycle impact assessment (LCIA) was performed for the year 2018. Life-cycle assessment (LCA) is a cradle-to-gate or cradle- to-grave analysis tool that can estimate environmental impacts associated with every stage of a product's life from raw material extraction through materials processing, product manufacturing, distribution, use, and end-of-life. This LCA study was completed in accordance with the UL Environment product category rule (PCR) for wooden pallets and International Organization for Standardization (ISO) 14040 and 14044 standards. Method The scope of this LCA covered the life-cycle stages of wooden pallet manufacturing starting from forest resource activities through end-of-life. This study represents wooden pallet primary manufacturing in the United States including analyses of wooden pallets with different feedstock material (i.e., softwood and hardwood) and focusing on multi-use pallets because these products represent the wooden pallet markets in the United States. The four wooden pallet types selected represent the wide range of designs used in the wooden pallet supply chain in the United States: the stringer light duty (LD), stringer heavy duty (HD), block LD, and block HD pallets. The selected design was the 48- by 40-in. (190- by 160-mm) pallet that is typically used in the distribution of fast-moving consumer and retail goods. These pallets are referred to a "distribution" or "retail" style. This is industry terminology that refers to a pallet that has the 48- by 40-in. footprint and a typical arrangement of deckboards. This pallet is used heavily in the retail industry. Historically, these types of pallets have been referred to as Grocery Manufacturers Association (GMA) pallets but are now called retail- or distribution-style pallets. The analysis was performed using weighted average industrial data collected from the wooden pallet manufacturers in the United States. The functional unit (FU) was selected as 100,000 lb (45.4 metric tons) of pallet loads of product delivered using wooden pallets, in line with the wooden pallet PCR. This FU most aptly represents the task performed by a pallet as opposed to past ones, which were based on only trip numbers or pallets produced. Previous studies did not consider the load carrying capacity of the pallets analyzed. In this study, the load carrying capacity in the racked across the length (RAL) basis was used to take into account how the pallet was transported and stored. The number of pallets required to fulfill the selected FU was calculated using the load carrying capacity and reference service life of the pallet analyzed. Life-Cycle Inventory Cradle-to-grave LCI flows for manufacturing wooden pallets consists of three life-cycle stages, (1) product stage, (2) use and repair, and (3) end-of-life. Life-cycle stages consist of information modules. Product stage was composed of raw material supply Module [A1], raw material transport Module [A2], and pallet manufacturing Module [A3]; use and repair stage was composed of use Module [B1] and repair–reuse Module [B2]; and end-of- life was composed of Module [C]. Module [D], which was beyond the system boundary, reported additional benefits of wood leaving the system boundary including coproducts from unit processes leaving the system at the production stage and grinding the wood material from unusable pallets and pallet boards for energy. Using mass allocation, the unit process modeling approach was followed for conducting the LCA using SimaPro LCA modeling software. Raw material supply Module [A1] was the most energy-intensive process. When lower heating values were used, the total cumulative primary energy consumption for cradle-to-grave production of wooden pallets was 225 MJ/ FU. Most energy came from fossil resources (52%), a small portion of energy needs came from nuclear (7%), and the remaining 41% came from renewable resources.

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