How do I count the emissions of a new CNC machine or press in Scope 3, and why can't I depreciate them over its life?
Report the machine's full cradle-to-gate emissions in Scope 3 Category 2, capital goods, in the year you acquire it. The GHG Protocol does not allow spreading them over the machine's life the way accounts depreciate its cost. Use the maker's figure if you can get one, otherwise estimate from its materials and label the estimate.
Why the whole machine lands in one year
The Scope 3 Standard counts the emissions that happened to make the machine, and those happened before you bought it. Depreciation is an accounting convention for spreading cost; it says nothing about when the emissions occurred. So a year with a big capital purchase shows a jump in Category 2, and the standard asks you to explain that jump, not smooth it.
Four ways to calculate, best first
- Supplier-specific: the machine maker gives a cradle-to-gate footprint for that model, ideally under ISO 14067.
- Hybrid: the maker gives its own Scope 1 and 2 for building the machine, and you add materials from a bill of materials.
- Average-data: machine weight by material (steel, cast iron, copper, electronics) multiplied by average factors per kg.
- Spend-based: price multiplied by an economic factor per rupee or dollar for machinery. Quick but the weakest, and prices change without any change in emissions.
What to record for an auditor or OEM
- The invoice, with the machine's HSN heading, such as 8457 for machining centres or 8462 for presses.
- The method, the factor sources, the weight and material split, and whether the figure is the maker's or your estimate.
- The fixed asset register entry that shows the machine was capitalised in that year.
What does not belong in Category 2
The electricity the machine uses after installation is your Scope 2. Spare parts and tooling you expense go in Category 1. A machine you lease rather than buy is Category 8 or your Scope 1 and 2, depending on your boundary approach.
Estimate: a 5 tonne CNC machining centre, average-data method
- Steel and cast iron: 4.6 t x about 1.9 t CO2 per t (worldsteel global average for steel) = 8.74 t CO2
- Motors, electronics, machining and assembly: assumed allowance of 0.5 to 3.0 t CO2e
- Estimate: 8.74 + 0.5 = 9.24 t to 8.74 + 3.0 = 11.74 t, about 9 to 12 t CO2e
- Reported in Category 2 for the year of purchase, labelled as an average-data estimate
The allowance is an assumption, not a published factor. Replace the whole estimate with the maker's figure when you get one.
What Senseible does here
Senseible keeps the machine invoice in its Scope 3 supplier evidence trail with the HSN heading and a SHA-256 fingerprint, and flags chapter 84 purchases for you to confirm as capitalised. It has no approved factor for finished machines, so that line shows Needs Data rather than a figure; the estimate is your own calculation.
Sources: GHG Protocol Corporate Value Chain (Scope 3) Standard (2011), Category 2, GHG Protocol Technical Guidance for Calculating Scope 3 Emissions (2013), Category 2, worldsteel sustainability indicators (CO2 intensity of steel)
Last reviewed 2026-10-15. No published factor exists for finished machines; the worked figure is indicative only.