Product Carbon Footprint (PCF)

The greenhouse gases attributable to one unit of a product across a defined part of its life cycle.

A PCF answers “what does one of these cost the atmosphere”. Unlike a corporate inventory, it is expressed per functional unit — per garment, per tonne, per square metre.

Three choices decide the number as much as the measurements do: the boundary (where the count starts and stops, e.g. cradle-to-gate), the allocation rule when one process yields several products, and the emission factors used.

Two honestly-produced PCFs for the same product can differ substantially if those choices differ. That is why a footprint without its method stated is not really a footprint — and why a figure that cannot be recomputed is difficult to defend when a customer or auditor asks how it was reached.

Official source: ISO 14067 ↗

Functional unit The quantity of product a footprint is expressed per — one garment, one tonne, one square metre, one kWh delivered.
Cradle-to-gate A boundary that counts emissions from raw material extraction up to the factory gate — excluding distribution, use and disposal.
Allocation How the emissions of a process that yields several outputs are divided between them.
Emission factor The coefficient that converts an activity — a kWh, a kilogram, a tonne-kilometre — into greenhouse gas emissions.