One of the first questions manufacturers ask when they request a product carbon footprint is a fair one: according to what, exactly, do you calculate it? In the world of Environmental Product Declarations (EPDs) the answer is familiar — the core standard EN 15804, plus a product-specific complementary rule (a c-PCR) where one exists. For a standalone carbon footprint the logic is the same, but the headline standard is different. This article sets out what a product carbon footprint is calculated against, and how that differs from a full EPD.
The short answer
A product carbon footprint is quantified to ISO 14067, with the underlying life-cycle assessment carried out to ISO 14040/14044. The detailed calculation rules — the system boundary, the declared unit, cut-off criteria, allocation, and how global warming potential is counted — come from Product Category Rules (PCR), exactly as they do for an EPD. Where a PCR or c-PCR already exists for the product, its carbon-relevant rules are applied. Where none exists, ISO 14067’s own requirements and the programme’s general rules govern the calculation.
ISO 14067 — the headline standard
ISO 14067:2018 specifies the principles, requirements and guidelines for quantifying the carbon footprint of a product (CFP), consistent with international LCA standards. It defines what is in scope — greenhouse-gas emissions and removals across the life cycle, expressed in kilograms of CO2 equivalent per declared unit — and how fossil, biogenic and land-use-change carbon are treated. Importantly, ISO 14067 is climate-only: it does not cover the broader set of environmental indicators that an EPD reports.
Where the rules actually come from: Product Category Rules
ISO 14067 does not work in a vacuum. It explicitly directs that, where carbon-footprint Product Category Rules (CFP-PCR) are available, they shall be used; and where they are not, PCRs developed under ISO 14025 may be used as the basis, taking the parts relevant to greenhouse gases. This is the key point for anyone who already knows the EPD system: the source of the calculation rules is the same family of documents. A PCR or c-PCR written for an EPD already defines the declared unit, the system boundary, the modules (A1–A3, A4, and so on), cut-off rules and the GWP calculation. A carbon footprint simply uses the climate-relevant part of those same rules.
PCR and c-PCR — the EPD parallel
In an EPD, two layers of rules apply. EN 15804+A2 is the core PCR for construction products — it sets the common framework. On top of it sits a complementary PCR (c-PCR) for a specific product group, for example EN 16757 for concrete or EN 16908 for cement, which refines the rules for that category. A carbon footprint reuses this structure: if your product falls under a recognised PCR or c-PCR, the footprint follows its carbon-relevant requirements, so your figure is calculated on the same basis as everyone else in that category — and is therefore consistent and comparable.
What happens when no PCR exists
Not every product has a published PCR. When that is the case, the footprint is calculated to ISO 14067’s own requirements, supplemented by the programme’s General Programme Instructions, which set the default rules for declared unit, boundary and data quality. The result is still a defensible, independently verified footprint; it is simply built on the standard’s baseline rules rather than a category-specific document. As sector CFP-PCRs continue to be published, more products will move from the baseline to a category-specific basis over time.
How this differs from a full EPD
The relationship is best seen side by side.
| EPD | Product carbon footprint | |
|---|---|---|
| Headline standard | ISO 14025 + EN 15804+A2 | ISO 14067 |
| Calculation rules | Core PCR (EN 15804) + c-PCR | The same PCR/c-PCR — carbon-relevant parts; ISO 14067 + programme rules where none exists |
| Scope | Many environmental indicators | Climate only (GWP, kg CO2e) |
| Verification | ISO 14025 / EN 15804 | ISO 14064-3 |
| Result | Full environmental profile | A single, verified carbon figure per declared unit |
In one sentence: a product carbon footprint uses the same rule engine as an EPD, narrowed to climate and placed under the umbrella of ISO 14067.
Why it matters for comparability and your buyers
The reason this hierarchy exists is comparability. A carbon figure only means something if the next product in the same category was measured the same way — same boundary, same declared unit, same allocation. By anchoring the calculation in a PCR wherever one exists, the footprint your customers receive is not just a number, but a number they can place next to others with confidence. That is exactly what large buyers need as they collect supplier data for their value-chain (Scope 3) reporting under the CSRD.
In practice
Under the EPD Polska programme, a product carbon footprint is quantified to ISO 14067 (LCA to ISO 14040/44), follows the relevant PCR or c-PCR where one exists, uses IPCC AR6 characterisation factors, and is independently verified to ISO 14064-3 by a verifier separate from those who prepared the data. It is then published in our register, with a QR-verifiable entry — and can be issued as a climate-focused document or as a full EPD.
If you need a verified footprint for a customer, a tender or your CSRD reporting, see our product carbon footprint service for sample documents and the data we need, or contact us for a no-obligation quote.