However, in many cases, packaging options that are being compared have different characteristics so that a single-criterion approach cannot be used. For example, is it better to use a lightweight package derived from fossil resources or a heavier package derived from renewable resources? Is it better to ship goods in a heavy container that can be reused many times or in a light container that is used once then recycled? Life cycle inventory (LCI) and life cycle assessment (LCA) provide the quantified environmental information needed to make such decisions.
The terms “LCI” and “LCA” are often used interchangeably; however, there are important differences. The definitive resource document on LCI and LCA is the International Organization for Standardization (ISO) standard 14040: “Environmental management—Life cycle assessment—Principles and framework.” As defined in ISO 14040, LCA is the “compilation and evaluation of the inputs, outputs, and the potential environmental impacts of a product system throughout its life cycle.” ISO 14040 goes on to describe LCI as one of the four components of an LCA.
LCI is the foundation for the impact assessment and interpretation phases of LCA
ISO 14040 defines LCI as the “phase of life cycle assessment involving the compilation and quantification of inputs and outputs for a given product system throughout its life cycle.” That is, the LCI identifies and quantifies all energy and material flows entering and leaving the boundaries of the defined system. Flows include energy, solid wastes, and substances released to the atmosphere or to water.
The important benefit of LCI is that it provides a comprehensive, quantified basis for comparing the environmental results for packaging systems that have different sustainable characteristics (as in the earlier example of a lightweight package derived from fossil resources versus a heavy package derived from renewable resources). LCI translates qualitative characteristics into quantified results so that a decision can be made based on science rather than value judgments. LCI provides sufficient information for making system comparisons of results such as total energy and solid waste.
To make informed decisions about emissions an additional step is required—the LCIA
LCI produces an extensive list of emissions associated with each packaging system evaluated. Releases of individual substances can be compared for alternative systems, using a ‘less is better’ approach. However, results are usually mixed—with some emissions higher for one system and other emissions higher for another system. Thus, a method is needed to assess the effects of the various emissions to make a more informed decision.
Life cycle impact assessment (LCIA) provides a useful basis for comparing emission results. LCIA is the “phase of life cycle assessment aimed at understanding and evaluating the magnitude and significance of the potential environmental impacts of a product system.” LCIA condenses the long list of LCI emission flows to a more manageable list by classifying and characterizing the flows. It is important to recognize that there are some limitations of LCIA—the ISO definition of LCIA refers to potential environmental impacts.
In summary, LCI and LCA provide important information needed to assess the environmental sustainability of packaging systems. LCI results serve as the foundation of LCA, providing a complete inventory of energy, solid waste, and emissions to air and water. LCA builds upon the LCI results, using LCIA to evaluate potential impacts of the inventory flows.
In the December issue, look for guidance on a practical approach to using LCI for evaluating packaging sustainability.