Table 1 Exclusion and inclusion table.

1. The use phase of coffee machines, amount of nitrogen injected into pods, and the coffee itself (i.e., coffee bean production and roasting) are excluded for both kinds of pods.

1. All materials; components (e.g., lid, mesh, filter, shell, ring); and processes involved in each step of manufacturing both plastic and compostable coffee pods (i.e., injection molding) from cradle to gate with transport to the customer and EOL phases.

2. Although die casting is a part of lid production, due to lack of information, it was left out of the referenced thesis¹⁶ and in this evaluation.

2. Sensitivity analyses to understand the impact of variation in transportation and relevant EOL waste stream options on the overall model.

3. Compostable lid uses unbleached Kraft paper as a proxy for abaca fiber generally used for coffee filters. Similarly, for plastic cups, bleached Kraft paper is used as a proxy for abaca filter.

3. Projected scenarios are included in Supplementary Tables S11–S14 to inform readers regarding wet weight impacts.

4. Because organic printing ink was not available in any of the databases, this has been left out to avoid error.

4. Manufacturing and packing centers for both pods are assumed to be within the same facility.

5. Although the rim of the filter paper is coated with PE for adhesion to the ring, this process is not specified anywhere in literature and hence was not considered.

6. Coffee chaff, which the reference thesis¹⁶ assumed as part of the compostable ring, is excluded here because Biodegradable Products Institute certification for the compostable pod considered in this study specifies only PLA.

7. Only pods are considered for evaluation, without considering secondary packaging such as cardboard boxes and PLA bags covering the compostable pods.

8. Material losses were not considered in this model due to percentage uncertainty for the processes specified here.

9. The use phase of coffee machines, coffee bean production, roasting, and details related to single-serve machines are excluded as the goal is to understand the impacts of packaging.