ISO 14404-4:2020

Overview

ISO 14404-4:2020 - "Calculation method of carbon dioxide emission intensity from iron and steel production - Part 4" provides practical guidance for using the ISO 14404 series to calculate CO2 emission intensity for all types of steel plants. It defines boundaries, upstream emission considerations, emission factors and intermediate-product treatment across diverse process routes. The standard includes a Universal Calculation Sheet to consolidate emission sources from ISO 14404-1, -2 and -3 and gives additional guidance on exported slags, by‑product gas, stock evaluation and selection of calorific values and emission factors for electricity and fuels.

Key topics and requirements

• Boundary definition and scope: Establishes how to set the calculation boundary (site vs. life‑cycle upstream) and which intermediate products’ upstream emissions to include.
• Universal Calculation Sheet: A template covering emission sources from the ISO 14404 series to standardize CO2 intensity calculations across routes.
• Process-route guidance: Specific advice for:
  • plants with process routes not covered in Parts 1–3,
  • plants operating multiple process routes,
  • plants purchasing pig iron or semi‑finished/crude steel from outside,
  • rerollers and outsourced steel production activities.
• Emission factors and calorific values: Guidance on selecting appropriate emission factors and calorific values for electricity and fuels to ensure consistent energy‑based conversions.
• By‑product and material evaluations: Procedures for evaluating exported slags, by‑product gases and inventory (stock) impacts on CO2 intensity.
• Principles for calculation: Emphasizes relevance, completeness, consistency, accuracy and transparency in data collection and reporting.
• Supporting annexes: Annex A (energy conversion and intensity), Annex B (recommended and inappropriate applications), and template examples to aid implementation.

Applications and users

ISO 14404-4:2020 is intended for practical use by:

• Steel plant environmental and process managers calculating plant-level CO2 intensity.
• Sustainability and carbon‑reporting teams preparing consistent emissions disclosures.
• Auditors and verifiers assessing methodology, boundaries and data quality.
• Consultants and policy makers comparing process routes or designing decarbonization pathways.
• R&D and operations staff optimizing energy use and accounting for by‑product credits.

Practical uses include corporate reporting, benchmarking across plants and process routes, evaluating outsourced inputs (pig iron, crude steel), and supporting emissions reduction planning.

Related standards

• ISO 14404-1 (BF–BOF route), ISO 14404-2 (Scrap–EAF route), ISO 14404-3 (DRI–EAF route)
• World Steel Association “CO Emissions Data Collection User Guide” (methodological alignment)

For implementation, consult the full ISO 14404-4:2020 document and the other Parts in the ISO 14404 series to ensure compliance and consistent CO2 emission intensity calculation.