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Research Paper FPL–RP–707 10 of the wooden pallet primary production, recycling–reuse– repair, and disposal were generated based on the operational data for core processes, the raw data, and emissions on yearly operation of the manufacturers in year 2018, which was supplied by the facilities. Site visits were also conducted at various times and locations. 2.3 Forestry Operations and Lumber Production (A1) Primarily, HW lumber including precut and SW lumber including precut are used at wooden pallet manufacturing facilities, followed by plywood and OSB, although these are used in very small quantities. Some SW lumber was kiln-dried during lumber production depending on customer specifications. Forestry operations data including growing seedlings, regeneration, site preparation, planting, thinning, fertilization, and final harvesting were embedded in the lumber production adopted from Consortium for Research on Renewable Industrial Materials (CORRIM) reports representing U.S. operations. This stage, [A1], is also referred to as the raw material supply in this report. The LCI of SW and HW lumber production in the United States was retrieved from CORRIM reports (Milota 2015a, 2015b; Hubbard and others 2020). In addition to HW and SW lumber use, small amounts of plywood and OSB were used at some facilities, LCI data of which were adopted from CORRIM datasets (Oneil and others 2010; Puettmann and Kaestner 2016a, 2016b, 2016c). Table 5 presents the weighted-average wood material inputs used in the production of 1 m 3 of wooden pallet. 2.4 Material Transportation (A2) The wood raw material was delivered to the pallet manufacturing facilities using rail and truck transportation. The weighted average transportation of wood raw material is presented in Table 6. The majority of the materials were delivered by truck although some of the SW lumber and plywood were delivered by rail. 2.5 Wooden Pallet Manufacturing (A3) The raw material inputs included HW and SW lumber and included precut lumber. In addition, some facilities had limited amounts of engineered wood product inputs (plywood and OSB). The primary product output of new wood pallet manufacturing systems was wooden pallets. Coproducts included sawdust, hogged material, wood chips, scrap wood, and shavings. About 68% of the lumber used by the manufacturers was SW. To perform the mass balance, mass of the pallet output was calculated based on the volume of wood that constitutes a pallet. Where facilities did not report the value for pallet volume, it was assumed that a generic wooden pallet in the United States constituted 15 actual board foot (bf) (0.04 m 3 ) of wood material (Gething 2018). This value was higher than was reported by Kočí (2019) at 12 bf (0.03 m 3 ) per Table 5—Wood resources used per cubic meter wooden pallet manufactured Wood material Unit Weighted average Hardwood lumber m 3 4.56E–01 Softwood lumber (green) m 3 2.10E–01 Softwood lumber (dry) m 3 4.99E–01 Plywood m 3 9.41E–03 Oriented strandboard m 3 7.40E–04 Table 6—Weighted-average transportation by mode for materials to wooden pallet manufacturing facility per cubic meter pallet manufactured Material Unit Mode Weighted average Precut hardwood lumber tkm Truck 5.33E+01 Precut softwood lumber tkm Truck 1.56E+02 Hardwood lumber tkm Truck 6.19E+01 Softwood lumber tkm Truck 1.60E+02 Softwood lumber tkm Rail 3.14E+01 Plywood tkm Rail 5.66E–02 Plywood tkm Truck 7.99E–01 Oriented strandboard tkm Truck 3.75E–02 pallet for central–eastern European block pallets. However, other studies reported that the wood content in a pallet ranged from 8.6 to 17.6 bf (0.02 to 0.04 m 3 ) (McKeever and others 1986, Carrano and others 2014, Park and others 2017, Kočí 2019). In the United States, it is common to report wood use in actual bf for pallet production unlike most other wood products. Manufacturers reported the information on the species used and the region the lumber was sourced from and if it was green (freshly cut) or dry. Wood flows in the gate-to-gate pallet manufacturing system were determined on an oven-dry (OD) kilogram basis. The results of the weight-averaged mass balance are provided in Table 7. The overall mass balance difference was less than 3%. A mass balance difference of less than 10% is good for wood product production, and a difference of less than 5% is excellent (Bergman and Bowe 2008). The wooden pallet manufacturing system considered three unit processes: wood preparation and board shaping, assembly–nailing, and supplementary processes. Supplementary processes included treatment, stamping, and painting. Inputs and outputs of each process based on weighted-averaged data from new wooden pallet manufacturing facilities is provided in detail in Tables 8 and 9. Unit process flows are presented in per 100,000 lb (45.4 metric tons) of pallet loads of product delivered. (see Appendix C for LCI per pallet manufactured). Wood material (primarily lumber) entering the pallet production system was converted on a mass basis into pallets at a rate of 82% with the remaining wood out being sawdust, hogged

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