What is a declared unit in a PCF?
A declared unit fixes the amount behind a partial product carbon footprint (PCF), such as one kilogram, one litre, one square metre, or one piece. It is suitable for an intermediate product when its eventual function is unknown. The result is reported as kg CO2e per that exact amount.
Why does a declared unit matter to you?
A customer cannot interpret your PCF without its denominator. A figure of 0.68 kg CO2e per carton is different from 0.68 kg CO2e per kilogram. PACT requires declaredUnitAmount, declaredUnitOfMeasurement, and productMassPerDeclaredUnit; use zero when mass is irrelevant.
How does a declared unit work?
Use the unit required by the named method or product-category rule. Record the product ID, amount, measurement unit, product mass where relevant, boundary, and reference period. Put every input on the same basis, total the included emissions, then divide by the number of declared units.
What mistakes should you avoid?
- Writing “per unit” without stating whether that means a piece, kilogram, litre, or another measure.
- Changing the denominator after calculation without converting both the product quantity and the emissions result.
- Using a declared unit for a final product when the method requires a functional unit covering service, duration, and quality.
Is a declared unit the same as a functional unit?
No. A declared unit states an amount of product. A functional unit states the service delivered, including its magnitude, duration, and expected quality. Use the functional unit when the final function is known and the method requires it.
What should you send with a declared-unit PCF?
Send the product ID, declared amount and unit, kg CO2e per declared unit, product mass if relevant, boundary, reference period, calculation file, and the method or product-category rule used.