"A product carbon footprint (or PCF) is the calculation of all of the greenhouse gas (GHG) emissions generated in the supply chain of a specific product. It is usually expressed as a carbon intensity.
To calculate the PCF, use the formula activity emissions factor for every activity, to develop the product’s emissions inventory. If your production process also involves co-products or by-products, the GHG Protocol sets out methods to ensure your emissions calculations relate only to the product under analysis.