Choice of the functional unit in LCA for the environmental display of food products
The Life Cycle Assessment (LCA) method seems, to date, to be the most operational in the short term for providing environmental indicators on the scale of food products for their environmental display. Thus, the "LCA base" would constitute the main basis of product information for consumers. In the context of LCA, the reference unit is the Functional Unit (FU).

In parallel with the national experiment on the environmental display of food products, a working group, under the aegis of the RMT Actia Écoval, has been set up to propose elements of reflection on the UFs specific to food.

The objective of this group is to provide elements for reflection on the relative relevance of UFs other than the mass unit (1 kg or 100 g of product consumed), which is often used by default. The methodological approach of this work is based on the LCA methods used in Agribalyse 3.0 and on the ANSES Ciqual table of nutritional values.
A panel of UFs for LCA of food products was tested based on mass, recommended serving size or calorie or essential nutrient content.
or essential nutrients.

The main findings of the simulations are that the mass UF can be adapted to differentiate between similar products (brand A vs. brand B), but appears unsatisfactory for very different products (from different product categories). Indeed, using this UF applied uniformly to all products to calculate a product environmental score (e.g. score provided for 100 g of product consumed whatever the product) would bias some inter-category comparisons made by consumers and could lead to erroneous choices not leading to environmental gains.

Nevertheless, the work and discussions carried out underline the difficulty of identifying satisfactory alternatives to a mass UF as long as a single UF is sought that cuts across all products. Indeed, each option has a number of advantages and disadvantages that do not allow clear recommendations to be made; some UFs are suitable for some types of products, but not for others. The UFs based on the nutritional portion have the advantage of assessing the environmental impacts in relation to the real service provided by the food (majority nutritional intake or energy intake to the body).

The work carried out also underlines the interest of reasoning at the level of a product segment with a view to allowing an intra-category comparison. This approach makes it possible to envisage more appropriate UFs, but requires prior work on product segmentation.

Publication by Laura Farrant (CTCPA), Margaux Colombin (CTCPA), Gilles Nassy (IFIP), Fabrice Bosque (ITERG), Didier Majou (ACTIA), published in Cahiers de l'IFIP, vol. 7, n°2, 2021