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studies. These include the bene fi ts of using the IPSA method in comparison with conventional facility-level allocation approaches, the bene fi ts of using newly-developed US regionalized electricity life cycle inventory, the use of an openLCA version of the EPA Waste Reduction Model (WARM), and the use of new functionality for advanced scenario modeling in openLCA software, all of which are not described elsewhere. It also provides a cradle-to-grave paper towel life cycle inventory of high data quality from a major global manufacturer with detailed contribution analysis describing the results from life cycle impact assessment.
P & G scientists in research, method development, application, and collaboration through the professional society, “ Society of Envi- ronmental Toxicology and Chemistry (SETAC) ” and local projects (Curran, 2000; Fava et al., 1991; Jolliet et al., 2004, 2014; Margni et al., 2007); while providing EPA's researchers the opportunity to develop and apply tools, including newly developed LCA soft- ware (Gooch and Mack, 2012). This collaborative effort addresses the following questions: 1) What product assessment approaches provide accurate and actionable information about social, economic, and environ- mental pillars of sustainability? 2) Can these approaches inform how changes in product design and manufacturing in fl uence these pillars up and down the supply chain? 3) Is there an assessment framework that puts it all together practically, ef fi ciently, and is actionable in any function and for any product? P & G selected paper family products, and in particular paper towels, as the subject of an initial targeted effort to address these questions. This paper towel LCA study is a key objective of the effort, where its results serve as the basis for the integrated sustainability metrics (Ingwersen et al., 2016). P & G has a history of using LCA to assess products and guide innovation (Saouter et al., 2002; McDougall et al., 2008; Weisbrod and Loftus, 2012; Weisbrod and Van Hoof, 2012; Van Hoof et al., 2014). The above questions stem from that experience. For the EPA, this is an opportunity to work with a leading global manufacturer to advance sustainability science with real application to consumer products with global supply chains (Ingwersen et al., 2014; Weisbrod and Loftus, 2012; Weisbrod and Van Hoof, 2012; Young et al., 2012). One example of the CRADA results, incorporated and further tested in this LCA, is the Industrial Process System Assessment (IPSA) methodology (Sengupta et al., 2015a). IPSA is a multiple step allocation approach for connecting information from the production line level up to the facility level, and vice versa, using a multiscale model of process systems (Sengupta et al., 2015a). The method helps resolve challenges in assessing multi-product or multi-production line systems (Bousquin et al., 2012). While this LCA model is foundational to exploring new inte- grated sustainability metrics, it is also designed to stand-alone. It thoroughly evaluates different supply chains and production processes used by two lines making paper towels at two facilities in the U.S. in 2012. The lines differ by age, location (Albany, Georgia vs. Box Elder, Utah), and technology. Other studies pub- lished on paper products do not have the resolution of assessing product impacts to the level of a single production line in a multi-line/product manufacturing facility (Madsen, 2007; Montalbo et al., 2011; Joseph et al., 2015; Boguski, 2010). It in- corporates detailed data from the IPSA allocation method, updated data on regional US electricity grids and pulp produc- tion, and a normalization procedure to identify key processes and materials that contribute most to potential environmental im- pacts in the life cycle of a consumer good. P & G bene fi ts from the LCA results for having the most accurate and recent model of Bounty to use as a benchmark to compare innovations to. It also serves to compare the value of conducting a complex LCA relative to other more simple methods, such as tracking energy use and waste generation (i.e., would the same priorities to improve processes or materials be identi fi ed by a cost and resource analysis as by an LCA?). For the average LCA practitioner, this study demonstrates a number of important advances that can improve the quality of LCA
2. Materials and methods
The scope of this analysis is cradle-to-grave. Foreground data account for forestry and wood chip production, pulp production, papermaking and converting, multiple transportation steps, and end-of life of all wastes. The Life Cycle Inventory (LCI) data are aggregated at the following levels: forestry and pulp production, pulp transport, paper towel production, fuels for each paper towel facility, electricity for each facility, product distribution, and end- of-life. Product use by a consumer is assumed not to lead to any measureable impact. The study is conducted on one roll of Bounty regular towels. The unit is not based on function, because there are many ways that people commonly use paper towels. The two lines being compared make the same formulation of towel, so using one unit of the product for comparing processes and equipment function is more useful. An iterative approach was taken where a preliminary screening- level LCA was performed in order to anticipate important sources of impact and direct subsequent work. The analysis was performed according to the same methods described here, using preliminary inventory data representing a single limited supply chain with primarily secondary data from the US Life Cycle Inventory (USLCI) (NREL, 2013) and Ecoinvent 2.2 (ecoinvent Centre, 2010). Pre- liminary results indicated the potential importance of pulp and direct energy consumption (particularly electricity) at the paper- making facility to many impact categories, and the importance of allocation choices/assumptions (Ingwersen et al., 2013). Therefore, additional efforts were made to improve the data quality of the pulp and electricity LCI, and to develop a more accurate method for allocating impacts from the papermaking facility to the Bounty product of interest. The LCA was conducted by both EPA and P & G researchers working with EXCEL ® spreadsheets and openLCA framework 1.4 ( © 2007 e 2015 GreenDelta). ISO 14040 standards are followed and the highest level of data quality is utilized whenever available (ISO, 2006).
2.1. Inventory modeling
Original LCI data from suppliers and P & G for pulp production and transport, paper towel production, and product distribution are used in the study. 2.1.1. Pulp production and transport Pulp production is represented by a set of unit processes for Kraft pulp (almost pure cellulose) used for paper towels, referred to henceforth as Pulp. Fig. 1 shows the basic steps in pulp production from harvest through arrival at the paper facility. Transportation between the processes is not pictured, but is included in data for forestry, sawmill, pulp mill, and paper facilities. The original pulp data were secured from multiple suppliers in several countries from 2010 to 2014. These con fi dential LCIs cover material sourcing and production beginning with forestry
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