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Use phase of apparel: A literature review for Life Cycle Assessment with focus on wool

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This report presents a literature review of clothing use phase. The purpose is to support improved methodological development for accounting for the use phase in Life Cycle Assessment (LCA) of apparel. All relevant textile fibres are included in the review. However, the main focus is on wool. We ask whether the use of wool has different environmental impacts than clothes in other fibres. The report builds on a review of literature from the past 20 years. The review showed that clothing made from different materials are used, and reused in different ways. Wool is washed differently as it has about ten degrees lower washing temperature than the average laundry in Europe. Wool is also more likely to be either dry-cleaned or washed by hand than other textiles. Moreover, when dried, it is less likely to be tumble-dried. When comparing the number of days between the washes of different types of clothes, we found that respondents were likely to use their woollen products about twice as long between washes compared to their equivalent cotton products. We also found that woollen products had a longer average lifespan and were more likely to be reused or recycled. There is a lot of research-based information available concerning the use and re-use of clothing, and we believe there are sufficient results available on which to base LCA studies. Furthermore, we believe that environmental tools that compare different fibres but exclude use phase provide misleading results Including the use phase in fibre ranking benchmark tools will improve the rigour and accuracy of these tools for all fibres, compared to reporting results for fibre production only. However, we have also shown that there are several methodological, conceptual and empirical knowledge gaps in existing literature.
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... The washable stock represents the fraction of clothing in a given country that is active, meaning it has been worn within the past 12 months and is washed. According to published literature, 28-30% of in-use apparel is considered inactive [58]. To keep our estimates conservative, we assumed that 25% of clothing is inactive. ...
... The numerator of this equation represents the washing capacity of country c; H c represents the number of households in country c that own washing machines, W c is the number of washes per households per year [58], and L c is the average load capacity [58] of country c. In the denominator, T c is the in-use stock of country c that is washed by washing machine (S2 Data in S2 File), and 0.75 is the fraction of apparel that is considered active and able to be washed. ...
... The numerator of this equation represents the washing capacity of country c; H c represents the number of households in country c that own washing machines, W c is the number of washes per households per year [58], and L c is the average load capacity [58] of country c. In the denominator, T c is the in-use stock of country c that is washed by washing machine (S2 Data in S2 File), and 0.75 is the fraction of apparel that is considered active and able to be washed. ...
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Synthetic microfibers are found virtually everywhere in the environment, but emission pathways and quantities are poorly understood. By connecting regionalized global datasets on apparel production, use, and washing with emission and retention rates during washing, wastewater treatment, and sludge management, we estimate that 5.6 Mt of synthetic microfibers were emitted from apparel washing between 1950 and 2016. Half of this amount was emitted during the last decade, with a compound annual growth rate of 12.9%. Waterbodies received 2.9 Mt, while combined emissions to terrestrial environments (1.9 Mt) and landfill (0.6 Mt) were almost as large and are growing. Annual emissions to terrestrial environments (141.9 kt yr-1) and landfill (34.6 kt yr-1) combined are now exceeding those to waterbodies (167.2 kt yr-1). Improving access to wastewater treatment is expected to further shift synthetic microfiber emissions from waterbodies to terrestrial environments. Preventing emissions at the source would therefore be a more effective mitigation measure.
... The parameters that are required to be assigned to include the use phase in LCA studies are as follows (Laitala, Klepp, and Henry 2017). ...
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Due to the rise in clothing consumption per person and growing consumer awareness of environmental issues with products, the textile industry must adopt new practices for improving sustainability. The current study thoroughly investigates the benefits of using organic cotton fiber instead of conventional cotton fiber. Because of the extensive use of natural resources in the production of cotton, the primary raw material for textiles, which accounts for the environmental effects of a pair of jeans, a life cycle assessment methodology was used to examine these effects in four different scenarios. The additional scenarios were chosen based on the user preferences for washing temperatures, drying methods, and the type of cotton fiber used in the product. The environmental impact categories of global warming potential, eutrophication potential terrestrial ecotoxicity potential, acidification potential, and freshwater ecotoxicity potential were analyzed by the CML-IA method. The life cycle assessment results revealed that the lowest environmental impacts were obtained for scenario 4 with 100% organic cotton fiber with an improvement of 87% in terrestrial ecotoxicity potential and 59% in freshwater ecotoxicity potential. All of the selected environmental impacts of a pair of jeans are reduced in all scenarios when organic cotton is used. Additionally, consumer habits had a significant impact on all impact categories. Using a drying machine instead of a line dryer during the use phase is just as important as the washing temperature. The environmental impact hotspots for a pair of jeans were revealed to be the eutrophication potential, acidification potential, and global warming potential categories during the use phase, and the terrestrial ecotoxicity potential and freshwater ecotoxicity potential categories during the fabric manufacturing including cotton cultivation. The use of organic cotton as a raw material in manufacturing processes, as well as consumer preferences for washing temperature and drying methods, appears to have significant environmental impacts on a pair of jeans’ further sustainable life cycle.
... Methods of cleaning clothes vary greatly around the world. Removing odour by washing textiles in the washing machine with detergents is by far the most common, but in some regions, such as China, washing by hand is still important (Kruschwitz et al. 2014;Henry 2017b, Laitala, Klepp, andHenry 2017a). There are also means to clean textiles without or with less water, such as airing, steaming, stain removal, physical removal (brushing, vacuuming, or beating, shaking and hanging outdoors), or dry-cleaning. ...
... In this case, standard use conditions provide for regular washing. As indicated in [22], at present, washing machines are prevailingly used across most continents. While the use of raw materials and clothing production remains an important source of negative impacts during the life cycles of the garment, the electricity consumption of the washing machine during the use phase is a significant source of environmental impact. ...
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Improving national electricity mixes and increasing a share of renewable energy covered by credible and reliable tracking systems are vital topics, also in a context of life cycle assessment. There are many publications devoted to the relevance of energy in the life cycle of products, but only few LCA examples applying residual mixes have been found in the literature. The paper presents the results of an LCA study for a refrigerator calculated with using different electricity mixes and technologies. The life cycle was divided into eight stages and the electricity consumption was modelled as renewable energy, national residual mix, or national supplier mix. Electricity mixes for three different countries were selected and used. The study aimed to answer the following questions: “what are the most relevant elements in the life cycle of the analysed refrigerator?”, “do the elements change if various electricity mixes are applied?”, and “what differences are there in the environmental impact of electricity generation modelled as residual and supplier mixes?”. From the life cycle perspective, not only may differences in national electricity systems between countries turn out to be important, but equally significant may be the choice between different types of mixes for a certain country.
... The worst practice washing method (S2W) involved the washing of a single garment in an older washing machine, rated B for electricity efficiency. Dry cleaning also had high impacts and these are known to vary (Laitala et al. 2017b and references therein); however, a preliminary analysis showed impacts were less than from a single garment washed in a contemporary machine at 40 °C and therefore a change in dry cleaning frequency was not modelled for the S2W. Modelling of a B energy efficiency-rated washing machine was justified on the prospect of residual consumer ownership (Michel et al. 2016). ...
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... The data was sorted in two ways, by "per respondent" (N = 1111), and "per garment" (N = 53 461). The data in China was collected differently to that of the other countries to enable comparison of more similar consumer groups, in terms of living standards, in the five countries, while also using the same design as at the 2012 study [4,11,40]. With this in mind, the data from China was collected from Tier 1 and 2 cities (Beijing, Shanghai, Guangzhou, Shenyang, Taiyuan, Nanjing, Hefei, Fuzhou, Changsha, Chengdu, and Xi'an) instead of the whole country. ...
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... In the following, we will discuss different units used to describe lifespans based on a literature survey on clothing consumption [24]. In addition to years, the units include the number of wears, the number of users, and cleaning cycles. ...
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