LCA frequently examines the life cycle of various products for which the production phase appears to carry the largest share of environmental burdens. However, we often assume in our models that the product’s material mass remains to the product’s end-of-life (EOL) phase. At EOL management, the material product is then usually modeled as a split between recycling, landfilling, and incineration with and without energy recovery. Often – not always but often, the use and EOL phase burdens are dwarfed by those of the production phase. However, in many material product systems, it also may be relevant to account for dissipative material losses occurring in the use phase. A recent example in the environmental news is that of microfiber release from synthetic textiles such as nylon, polyester, and acrylic, e.g., in apparel product systems. Some synthetic textiles are even composed of plastics recovered from the EOL of other product systems in an attempt to reduce overall plastic waste. From these material lifecycles, plastic microfibers can be released during the use phase, for example, at each product wash cycle. Much of the plastic microfiber release escapes wastewater treatment technologies. For a single product use, the amount of microfiber released is negligible, but collectively this phenomenon is affecting both marine and freshwater on a massive scale. In fact, synthetic microfibers are easily mistaken as food by marine fauna and so can end up on our dinner plates.
Where should system boundaries be drawn to reflect this issue in modeling and at which point should correction occur? Do we include upstream plastic products from which EOL materials are recovered and converted to synthetic fibers? For laundered textiles, should manufacturers of washing machines install new filtering devices and retrofit existing equipment? Will users become sufficiently aware and make new decisions about their textile material origins? Should wastewater treatment plants update technology to account for microfiber pollution? These are the important questions for relevant stakeholders in society. Meanwhile, as LCA analysts, this example should be referenced as we improve our assessment of use phase losses in all product systems. We can more carefully consider the physical potential and nature of dissipative use-phase material loss in various product systems by: considering scenario analysis for existing and potential technologies, considering market changes which might affect these scenarios, and updating our quantitative modeling methodologies to reflect a more steady-state approach (see example study: Improved algorithms for LCI modeling of reusable packaging).
