How do I calculate the carbon footprint of stainless steel surgical instruments?
Multiply the stainless steel per instrument, including forging and machining scrap, by your steel supplier's per-kg figure. Add forging fuel, heat treatment, machining, polishing and passivation, cleaning and packing, then divide plant energy by instruments passed.
Materials
- Martensitic or austenitic stainless bar or blanks by weight.
- Tungsten carbide inserts, where used.
- Pouches and cartons.
Process
- Drop forging and trimming, with furnace or induction heating.
- Hardening and tempering.
- Grinding, polishing, passivation and ultrasonic cleaning.
Per piece
Report per instrument type, since a scalpel handle and a retractor differ widely in steel weight.
Worked example: instrument unit per piece (one month)
- Electricity: 25,000 kWh x 0.710 = 17,750 kg CO2
- LPG: 500 kg x 2.98 = 1,490 kg CO2
- Instruments passed: 50,000
- Plant total: 19,240 / 50,000 = 0.385 kg CO2 per instrument
- Add stainless steel for the full figure
Inputs are illustrative; use your own bills and production records.
What Senseible does here
Senseible reads the plant's electricity bills (CEA grid factor 0.710 kg CO2 per kWh, CO2 Baseline Database version 21.0) and fuel invoices (IPCC 2006 defaults) into a fingerprinted Scope 1 and 2 record, the plant-level input to a per-unit figure. Bought-in materials go to the supplier evidence trail; product reports are self-declared drafts.
Sources: GHG Protocol Product Standard, ISO 14067:2018, Carbon footprint of products (iso.org), IPCC 2006 Guidelines, Volume 2 Energy (fuel defaults), CEA CO2 Baseline Database, version 21.0
Last reviewed 2026-10-20.