When a customer asks for a product's carbon footprint, first confirm the function being compared, the product unit and the life-cycle stage. The same kg CO₂e figure cannot be used to rank products directly if boundaries and assumptions differ.
Who should consider this and when
Start with a representative model when responding to product data requests, finding reduction hotspots, preparing a label or addressing a supply-chain requirement. Reassess whether an existing study still represents the product after important changes to materials, energy or processes.
Connect the BOM to actual production
Design quantities need to be checked against scrap, yield and batch differences; site energy may cover several production lines. Keep assumptions about service life, frequency, geography and end-of-life treatment separate from site records, and document sensitivity and limitations.
Method and study boundaries
ISO 14067:2018 sets requirements for quantifying and reporting product and partial product carbon footprints using life-cycle principles. Define the functional or declared unit, system boundary and applicable product category rules (PCR), then prepare the inventory and results. The GHG Protocol Product Standard also provides a product accounting method; choose according to the intended use.
A study may cover raw materials, manufacturing, transport, use and end-of-life treatment. If it stops at the factory gate, state the partial footprint boundary. ISO 14067 focuses on climate change; carbon offsetting and communication are outside its scope. Confirm separate rules for labels and external claims.
Workflow to discuss
- Retain the customer request; confirm model, product unit, purpose and boundary, and check applicable PCR.
- Organize BOM, volume, process, energy, logistics and upstream data; flag missing items and quality issues.
- Assess detailed measurement and allocation methods, documenting the rationale, factors and key assumptions.
- Review results and hotspots; prepare the study report, limitations and items to update after changes.
Preparation and possible deliverables
For an initial discussion, provide product specifications, BOM, process, volume and existing carbon data; add transport, use and treatment information according to the boundary. Possible deliverables include the study scope, inventory, calculation workbook, data-quality review and draft report. Verification, label applications and public comparisons are defined separately.
Timing and fees
Model differences, supplier data, production-line allocation and life-cycle scope determine effort. Database licenses, third-party verification and label fees should be estimated separately; total cost should not be inferred from model count alone.
Frequently asked questions
Can a company GHG inventory be directly converted into a product result?
Facility data may be an input, but it must still be connected to the product unit, allocation and upstream and downstream stages. The studies have different subjects.
What if a supplier has no emissions figures?
Assess suitable secondary data and document its source and limitations; prioritize improving data for significant materials. Check any specific customer or PCR requirements separately.
Can electricity be averaged across products made on a shared line?
First check whether meters, operating hours or process activity support allocation. If allocation is necessary, document its basis rather than averaging solely for convenience.
Does verification allow us to claim a lower footprint than competitors?
Also confirm function, boundary, method, data quality and comparison rules. Verification is not the same as obtaining a carbon label. Map external claims to supporting evidence separately.
Official references
These sources support the methods and scope. The process and possible deliverables are suggestions for project discussion.