LCIA (Life Cycle Impact Assessment) is a phase of life cycle assessment where potential environmental impacts are calculated.

LCIA Method

An LCIA method defines a methodology for assessing a particular type of potential impact, such as global warming. The impact category indicator and reference quantity specify how impact is quantified.

LCIA methods are activated in the Used Oil LCA tool by checking boxes in the Active column of the LCIA Methods table on the tool's default view (Home). LCIA methods are color coded by impact category.

Click on an LCIA method name to navigate to the LCIA Method view. This view displays important LCIA method attributes and characterization factors. To see the data source, an ILCD* formatted XML file, click on the ILCD Reference LCIA Method Data Set link.

* ILCD : International Reference Life Cycle Data System, developed by the European Commission.

Characterization Factors

Characterization factors associate impact factors with elementary flows. An elementary flow is material or energy that is directly input to or output from the environment.

In the LCIA method view, the LCIA Characterization Factors panel contains a grid displaying characterization factors with LCIA factor parameters. Select a scenario to see its parameters. If you own the selected scenario, you may edit the parameters (see Editing Parameters).

LCIA Results

The app's primary purpose is to compute LCIA results. These can be accessed in several different ways and at different levels of detail.

Process LCIA Results

A process is an individual node in a fragment that converts inputs to outputs. When navigating to a particular process instance , the LCIA results from that instance will be shown in rainbow charts, with one chart for each LCIA method:

Rainbow chart for non-cancer human health impacts due to metal emissions from MDO combustion.

Process LCIA results can also be accessed by adding the process to the LCIA Comparison and then clicking on the process name.

Fragment LCIA Results

A fragment is a portion of the life cycle inventory model shown as a tree. Fragments are explored using the fragment flows view. From this view, clicking on the "Show LCIA Results" button will show the LCIA results from the fragment, grouped by life cycle stage. If the fragment is part of a non-base-case scenario, the model base case results will be shown alongside.

Each active LCIA method has a panel containing waterfall charts for each selected scenario. A waterfall chart shows the cumulative LCIA result at each stage of the selected fragment's life cycle. Note that in this view, the Model Base Case fragment is always shown having the same activity level as the scenario fragment. Therefore, the view will show changes within the fragment and sub-fragments, but will not show any changes that result from parent fragments.

Lifecycle stages form the vertical axis of each chart, such that the first stage is at the top and the last stage is at the bottom. The horizontal axis represents LCIA result, given in the method's quantitative reference unit. Its range is consistent across scenarios to facilitate comparison.

A stage having a positive result is represented with a bar that starts on the left and ends on the right, while a negative result starts on the right and ends on the left. The first bar always starts with result = 0. The end of each bar is connected to the start of the next bar until the last bar whose end connects with the horizontal axis to indicate the end result.

In the Fragment LCIA view it is possible to move through parent fragments and sub-fragments, just as if you were navigating through the fragment in the Fragment Flows view.

Scenario LCIA Results

It is also possible to compare the LCIA results from multiple scenarios at once by clicking on the "Scenario LCIA Results" link on the navigation bar. This view can only be used to compare different scenarios that share the same top-level fragment, because not all fragments are encountered in every scenario.

To use this view, first select the top-level-fragment at which you wish to perform the comparison, then select as many scenarios as desired which share that top-level fragment.