When you are doing an LCA, and a supplier presents an LCA-result or EPD, it might be possible to include characterized life cycle impact assessment (LCIA) results in your SimaPro model. This article presents the conditions and the steps to take.
First: be aware that the conditions for including LCA or EPD results in your LCA are strict. Not all EPDs are the same - on the contrary. The suppliers’ LCA (EPD) should have some of the same important starting points as your own LCA. Examples are:
System boundary, (ecoinvent) system modelling, allocation
Background data, e.g. ecoinvent vs U.S. Life Cycle Inventory
ecoinvent 2.2 ≠ 3.5 ≠ 3.9.1
Infrastructure (capital goods) included/excluded
Methods, e.g. ReCiPe 2008 ≠ 2016; IPCC 2021 ≠ 2013; EN 15804 + A1 ≠ EN 15804 + A2
IPCC, including or excluding CO2-uptake
including or excluding long-term emissions
Etc.
In practice these conditions are seldom fully met, unless very strict product category rules (PCR) are in place. If not met, it takes some experience to make a proper judgement about suitability.
Important: PRé Sustainability is not responsible for the choices you make and cannot provide support for the results generated with this approach.
There are three important steps to take for including LCIA results (e.g. from EPD) in your LCA:
1. Create substances with the name and unit of the impact categories and indicators/parameters in the most appropriate category under General data / Substances.
For example:
Under Raw materials:
kg Sb eq. Resource use, minerals and metals
MJ Resource use, fossils
m3 depriv. Water use
Pt Land use
…Energy, primary, renewable (MJ)
Water, fresh water use (m3)
Secondary material (kg)
Under Emissions to air:
kg CO2 eq. (one total category or individual subcategories like for fossil, biogenic, LULUC)
kg CFC 11-eq.
kg ethyl eq.
kg 1,4 DB-eq. Human toxicity
… (can also contain impact category results with waterborne emissions, emissions to soil)
(Waterborne emission and emissions to soil will therefore often be left empty)
Under Final waste flows:
Waste, non hazardous (kg)
Waste, hazardous (kg)
Waste, radioactive (kg)
…
Economic issues might be used for:
Components for re-use (kg)
Materials for recycling (kg)
Materials for energy recovery (kg)
Exported energy, electric (MJ)
Exported energy, thermal (MJ)
…
Please note that:
The unit shouldn’t actually be added in the substance name, as the unit is added in the SimaPro process and always characterized per standard unit in the method. But to avoid mistakes in quantity or unit (e.g. Resource use, fossils can be expressed in both MJ and kg Sb-eq.) it might be best to include the unit for information.
Numbering these ‘result substances’ at the beginning of the name is advisable since it might help to keep track. Start with “-” to ensure when sorting they appear on top of the list and the filtering option can be used. For instance, “-001 Climate change (kg CO2 eq) EN15804+A2”
It is advisable to really specify these ‘result substances’ by including information on the version of the method used, like “CO2 eq, fossil, IPCC 2017, 100 yr, ex uptake”.
2. Add these ‘result substances’ to the respective methods with a characterization factor of 1.
Create a copy of the method first, with a clear name describing the LCA/EPD ‘result substances’ addition.
Make sure that all ‘result substances’ you entered in step 1 are added in the method(s) that you want to use!
Be aware that whenever there is new version (update) of the standard method in the SimaPro database, you have to repeat this step.
Please refer to this article or this webinar recording for further information on creating your own method.
3. Now you can enter the LCIA-results in a new SimaPro process, by selecting the ‘result substances’ under Inputs from nature, Emissions to air/water/soil, Final waste flows and economic issues with the appropriate amounts.
If you have multiple LCIA-results/EPDs create a template process, with all the ‘result substances’ and zero values first, that you can copy to enter the LCIA-results.
Make sure that all you entered in step 1 is added in the process.
To check your EPD-input process, calculate the impact assessment with the method created at step 2: the result should match the EPD.