A reference product is the term used in the ecoinvent database to denote what is more broadly defined in LCA terminology as a Determining product. The reference product represents the primary Product output of an Activity for which a change in demand will directly affect the production volume of that activity.
In the context of ISO 14040 and 14044, the concept of a reference product aligns with the determining product definition. It is the product output whose market demand drives the activity's production decisions. When demand for the reference product increases or decreases, the activity scales its production accordingly, distinguishing it from by-products, whose production levels are dependent on the determining product rather than on their own direct market demand.
Within LCA databases and particularly in ecoinvent's data structure, the reference product serves as the functional basis for unit process datasets. Each activity dataset is constructed around its reference product, with all exchanges (inputs and outputs) related to producing one unit of this reference product. This standardisation enables practitioners to link activities together when constructing product systems and to scale activities appropriately based on the reference flows required to fulfil a specified functional unit.
The ecoinvent-specific terminology of "reference product" thus provides database-specific nomenclature for the same underlying concept as the determining product, ensuring consistency in how activities, their main outputs, and their environmental burdens are represented and linked within life cycle inventories.
