|Aspect||G-24 Collecting foreground and background data for product LCA|
||Different data need to be collected for a product LCA study. The most important data collection is usually the production stage especially for highly complex manufacturing processes. The data can be based on industry or companies involved in the project else on secondary sources e.g. background databases providing average datasets.|
related study objective
|☒ stand-alone LCA||☒ comparative assertion|
related study phase
|goal and scope definition||inventory analysis (LCI)||impact assessment (LCIA)||interpretation||reporting|
|new buildings||existing buildings||construction products||screening LCA||simplified LCA||complete LCA|
|Provisions||The practitioner should follow ILCD Handbook provisions as well as EN 15804 if more relevant and specific for the goal and scope of the study.The provisions of this aspect is linked to the “definition of system boundaries for product LCA”.|
||ILCD guidance should be followed. It needs to be precised that the data collection is a very time consuming step in the LCA. However, this step is highly linked to the overall quality of the study. The practitioner may face different challenges for collecting foreground or background data in practice.Generally speaking, the foreground data collection at the manufacturer plant should follow consistent rules (e.g. see ILCD provisions 184.108.40.206 Checking legal limits; provisions 220.127.116.11 Interim quality control).
General guidance for product LCA studies
The data collection should be conducted depending on the goal and scope of the study.Specific guidance for EPD studies
Depending on the EPD program, some already pre-verified background data may be made available for the practitioner. If so, there is no need to comprehensively review the background data as they are supposed to meet the quality guidelines and goal and scope of the PCR (e.g. EN 15804).
It is very important to comply as much as possible to the specific rules given in the PCR (EN 15804 but also national implementation). One key issue is to know where we need to stop collecting data from the manufacturer. Usually, he controls only the gate-to-gate processes. However, under some circumstances, he may also be responsible of upstream process e.g. extraction of clay. In that context, it may be relevant to collect primary data for this process instead of using secondary data available in background databases.
For the gate-to-gate stage (under the control of the manufacturer), the data collection is function of the type of EPD.
For single manufacturer’s EPD, data can be taken from 1 production site or averaged across more than one the production sites.
For group of manufacturer’s EPD, data are taken from different companies (their data may be already averaged internally if they have more than one production site). They need to be averaged (horizontal averaging according to the ILCD). In that case, it is very important to make sure that the different companies have similar environmental impacts for the production of the product. PCR (in every national context) may provide more specific rules than EN 15804 to calculate these group of manufacturer’s EPD. This issue being to make sure that the declaration is representative of the companies with a limited variability. By requesting a low variability on the final results (e.g. 10% for GWP, 20% for acidification) it leads to differentiate different group of companies that have different technologies and related environmental impacts. Otherwise, the issue is to have a company that has higher impacting production process being hidden under the “average” value thanks to the more efficient/less impacting production processes.
Guidance for E2B EI research projects
Within E2B EI research projects, some confidentiality reasons may lead the use only of generic data for both foreground and background system. In some cases, where the company is keen on giving the gate to gate information for the LCA study, the modelling will be more representative of the product.
The limits encountered during the data collection step should be part of the LCA report. The interpretation of results should be made according to the quality of data collected during the inventory analysis.