In Life Cycle Assessment (LCA), the preferred approach is always to describe a product in terms of its raw material composition—the “material 0,” meaning the base substances extracted from nature before any transformation. However, in practice, this level of detail is often unavailable, especially for complex manufactured products. In such cases, using a list of product components is acceptable, provided that the underlying assumptions and limitations are clearly documented.
Summary Recommendation
If only a list of manufactured components is available:
Use it as the starting point—it is better than excluding the material stage entirely.
Estimate the material composition or identify main materials whenever possible.
Leverage supplier emission factors if available.
Document all assumptions and note their expected influence on results.
This ensures that the assessment remains consistent, transparent, and methodologically acceptable—even in the absence of full material-level data.
For more details, please read the article below.
1. Understanding What LCA Measures
An LCA aims to quantify all energy and material flows required to produce a finished product, from resource extraction to delivery.
When an LCA dataset gives a carbon factor for aluminum, for example, that factor already includes the entire chain of energy used to extract bauxite, refine it, and process it into aluminum ready for use—sometimes including inbound transport.
Therefore, the deeper the material breakdown, the more accurately the LCA can trace the energy flows that led to the final product. Working with only “manufactured components” means skipping some upstream modeling—but it can still produce valid results if handled carefully.
2. When Component-Level Data Are Acceptable
If raw material information is unavailable, you can represent the product through its manufactured components (e.g., “screw,” “metal plate,” “plastic casing”). This approach is not ideal, but it is acceptable when:
The detailed material composition is confidential or unknown;
The components represent standard industrial items with known average emission factors;
The goal of the study is comparative or exploratory rather than certification-level precision.
In that case, make sure each component is described in sufficient detail (e.g., “steel screw,” “aluminum housing,” “ABS plastic cover”) to assign relevant LCA database factors.
3. Estimating Material Composition
When possible, estimate the product’s composition based on known or assumed proportions:
Best case: precise weight or percentage share of each constituent material.
Acceptable fallback: identify the 3–5 main materials by mass.
Minimum acceptable: use the primary material only, if it represents more than 80% of the product’s total mass.
Even rough estimates improve the model’s transparency and traceability. LCA practice accepts the use of estimations when data are missing, as long as they are explicit, justified, and transparent in the study documentation.
4. Using Supplier-Specific Emission Factors
Another valid approach is to use supplier-specific emission factors for purchased components.
If a supplier has already performed an LCA or provides a verified product footprint, you can directly use that factor—avoiding the need to model raw materials yourself.
If not, refer to the supplier’s technical sheet to infer the component’s likely composition and use corresponding generic LCA data.