Measurement purpose

Generating an average nationwide product-level GHG emissions intensity estimate collected across all U.S. facilities.

Generating a product-level embedded emissions estimate for individual importers’ imports, covering a scope consistent with ETS coverage of European industrial installations.

Generating site-specific emissions intensity estimates for the production of crude steel. The ISO 14404 series includes standards that are specific to production technology; worldsteel’s approach is not.

Generating site-specific emissions intensity estimates for the production of crude steel. Estimates are used for low-carbon certification program, company target-setting, and steel customer awareness.

Generating site-specific emissions and emissions intensity estimates for the production of crude steel. Estimates are part of a broader voluntary sustainability certification standard.

Emissions covered

GHGs include CO₂, N₂O, and CH₄. All scope 1 and scope 2 emissions are included. Scope 3 covers emissions embedded in externally sourced upstream material inputs.

GHGs include CO₂ only. Covers “direct embedded emissions” which include scope 1 emissions other than those associated with electricity generation and scope 2 emissions associated with heat received from other sources; and “indirect embedded emissions” which include emissions related to electricity consumption (which can be scope 1 or scope 2 depending on point of generation). Emissions embedded in externally sourced upstream material inputs (scope 3) are similarly divided and aggregated with the above.

GHGs include CO₂ only. All scope 1 and scope 2 emissions are included. Scope 3 covers emissions embedded in externally sourced upstream material inputs.

GHGs include CO₂, CH₄, NF₃, N₂O, HFCs, PFCs, and SF₆. All scope 1 and scope 2 emissions are included. Scope 3 covers emissions embedded in externally sourced upstream material inputs and those associated with downstream toll processing of finished steel mill products.

GHGs include CO₂, CH₄, NF₃, N₂O, HFCs, PFCs, and SF₆. All scope 1 and scope 2 emissions are included. Scope 3 covers emissions embedded in externally sourced upstream material inputs.

System boundaries (upstream materials covered)

Boundary includes emissions associated with extraction and processing of most upstream raw materials. Excludes emissions associated with transport. See figures 2.4 and 2.5 of this report for full coverage of processes covered under this investigation’s system boundaries.

Boundary includes emissions associated with processing of some key material inputs, but excludes emissions associated with mining and the processing of coke, flux materials, carbon electrodes, industrial gases other than hydrogen, all but three ferroalloys and alloying metals, and coating metals. Excludes emissions associated with transport.

Boundary includes emissions associated with processing of most upstream raw materials. Excludes emissions associated with extraction of materials and transport. The ISO 14404 series has slightly different boundaries depending on the production technology.

Boundary includes emissions associated with extraction, processing, and transport of materials.

Boundary includes emissions associated with extraction, processing, and transport of materials.

System boundaries (downstream products)

Covers emissions from all production of finished mill products. This includes products such as coated flat steel, tubular products, and wire. See investigation request letter in appendix A of this report for a full list and chapter 2 (“Covered Steel Products”) for a list of all product categories for which emissions intensity estimates were generated in this report.

Covers emissions from production of crude steel products and “iron or steel products,” a broad category of finished downstream steel mill products that is more expansive than the covered products under the USITC investigation.

Covers emissions from a facility’s production of crude steel. Does not cover downstream processes.

Covers emissions from a facility’s production through the hot-rolling stage.

Covers emissions from a facility’s production of crude steel. Does not cover downstream processes.

Allocation of emissions from waste gases

Emissions from waste gas combustion are fully allocated to the processes where that combustion occurs (or the processes that use energy generated on-site from waste gases). For more information see box 3.1 in chapter 3 of this report.

Emissions from waste gas combustion are allocated to the facility and process that created the gas. Exports of waste gas for use in another process or facility receive a credit based on displacement of natural gas use. Similarly, production processes that use waste gas sourced from a different process or facility use a lower natural gas emissions factor for that combustion of waste gas imports. This effectively shifts some of the waste gas combustion emissions from processes using the gas to the processes creating it.

Emissions from waste gas combustion are included in facility-wide scope 1 emissions. Exports of waste gas are assumed to displace alternative sources for electricity; they receive a scope 2 emissions credit based on the 2006 IEA world average CO₂ intensity of electricity.

Emissions from waste gas combustion are included in facility-wide scope 1 emissions. Exports of waste gas (including on-site use outside the system boundary) receive credits based on displacement of natural gas use or electricity generation using the local average mix of generation sources.

Emissions from waste gas combustion are included in facility-wide scope 1 emissions. Exports of waste gases (including on-site use outside of the system boundary) receive credits based on displacement of natural gas use or electricity generation using a global average mix of generation sources.

Allocation of facility-level emissions to products

Facility-level emissions are subdivided into subprocesses and further divided into unit-process level emissions based on “physical allocation” (i.e., by mass of output); unit-process-level emissions are then combined with emissions associated with upstream products internally consumed within the same facility.

Emissions are allocated using a similar approach to the USITC method, although product categories are broader. For facilities that do not externally ship any upstream products made on-site, a “bubble” approach can be used that avoids allocation of facility-level emissions into specific processes.

Emissions embedded in intermediate products shipped off-site are excluded. Because the estimation involves crude steel only, no allocation steps are needed to determine product-level emissions for crude steel or any downstream goods.

Emissions burden of intermediate products is not explicitly discussed. Standard notes that a product’s embedded carbon estimates should be determined in conformance with GHG Protocol Product Life Cycle and Accounting Standard, which forms the basis for the USITC’s allocation approach.

Emissions embedded in intermediate products shipped off-site are excluded. Because the estimation involves crude steel only, no allocation steps are needed to determine product-level emissions for crude steel or any downstream goods.

Scrap treatment

Scrap does not have embedded scope 3 emissions. The Commission’s questionnaire asked for data on the quantity and characteristics of scrap used in steelmaking (i.e., share of scrap that is post-consumer, home scrap, and carbon content) for supplemental analysis.

Scrap does not have embedded scope 3 emissions. Post-consumer scrap used as an input is presumed to have zero emissions burden, whereas carbon in pre-consumer scrap is considered under mass-balance calculations. Importers provide source installation’s quantity of scrap used in production, including the share of scrap that is pre-consumer.

Scrap does not have embedded scope 3 emissions. Standards do not call for gathering data on scrap receipts from external sources for any other reason.

Scrap does not have embedded scope 3 emissions from original steel production, but emissions from scrap collection and processing are explicitly included.

Scrap does not have embedded scope 3 emissions from original steel production, but emissions from transportation of scrap to the steel producer’s gate is included. The quantity of scrap used in crude steel production is required reporting to be able sell products as ResponsibleSteel certified.

Scope 3 emission requirements

Scope 3 emissions are calculated by multiplying activity data by emissions factors from two sources: (1) product-level emissions intensities of U.S. supplier facilities estimated by the Commission; or (2) default emissions factors collected or developed by the Commission (see appendix F in this report for more details).

Installations producing iron and steel products are required to report data on the emissions intensities of inputs (“precursors”) produced off-site. These data may be collected directly from the precursor producers. If these emission data were not available, installations were also allowed to use default values provided under CBAM until July 2024. After July 2024, installations may use those default values for 20 percent or less of their total embedded emissions.

Calculation of scope 3 emissions from primary data is highly recommended, though calculation methodologies are flexible, and could include a mix of primary source or local and regional secondary source information. worldsteel also supplies industry average upstream factors in the event primary data are not available. (ISO 14404 also has an upstream emissions factor table, with similar rules applied).

Scope 3 emissions are determined either based on primary source data (conforming to certain reporting requirements) OR unspecified “industry average data” with proper citation. Scope 3 emissions from purchased billets and slabs must be determined based on primary source data. The share of scope 3 emissions based on primary source data is also reported as a qualitative factor.

Scope 3 emissions are determined either based on primary source data provided by the supplier of upstream materials (conforming to certain reporting requirements) or on ResponsibleSteel default emissions factors (“embodied GHG values”). Many of these default emissions factors are taken from industry sources and multiplied by a factor of 1.2 or 1.6 to be purposely higher than industry averages.

Measurement purpose

Generating an average nationwide product-level GHG emissions intensity estimate collected across all U.S. facilities.

Generating product-level embedded emissions intensity estimates for individual importers’ imports, covering a scope consistent with ETS coverage of European industrial installations.

Establishing standardized guidance on the calculation of product-level GHG emissions, primarily in the primary unwrought aluminum segment and precursor segments.

Creating a North American lifecycle analysis of semi-fabricated aluminum products to improve understanding of the environmental implications of aluminum production. Also serves as a resource for development of EPDs and other sustainability reports, strategic planning, and sustainable development.

Creating North American industry average lifecycle analyses for aluminum extrusions with various finishes, to serve as a resource for the development of future EPDs.

Emissions covered

GHGs include CO₂, N₂O, CH₄, and PFCs (CF₄ and C₂F₆). Scope 1 process and fuel combustion emissions are included. Scope 2 emissions from purchased electricity, heat, and steam are included. Scope 3 emissions are from emissions embedded in externally sourced upstream material inputs.

GHGs include CO₂ and PFCs (CF₄ and C₂F₆). Covered “direct embedded emissions” which include scope 1 emissions other than those associated with electricity generation and scope 2 emissions associated with heat received from other sources; and “indirect embedded emissions” which include emissions related to electricity consumption (which can be scope 1 or scope 2 depending on point of generation). Emissions embedded in externally sourced upstream material inputs (scope 3) are similarly divided and aggregated with the above.

GHGs include CO₂, N₂O, CH₄, and PFCs (CF₄ and C₂F₆). Scope 1 process and fuel combustion emissions are included. Scope 2 emissions from purchased electricity, heat, and steam are included. Scope 3 emissions are from emissions embedded in externally sourced upstream material inputs.

GHGs include CO₂, N₂O, CH₄, and PFCs (CF₄ and C₂F₆). Scope 1 process and3 fuel combustion emissions are included. Scope 2 indirect electricity and thermal energy emissions are included. Scope 3 indirect emissions from sources not controlled by the company are included.

GHG inclusion corresponds with IPCC AR 5, which includes CO₂, N₂O, CH₄, SF₆, and PFCs (CF₄ and C₂F₆) and HFCs. Scope 1 process and fuel combustion emissions are included. Scope 2 indirect electricity and thermal energy emissions are included. Scope 3 emissions from externally sourced upstream inputs are included.

System boundaries (upstream materials covered )

Includes emissions associated with extraction and processing or production of most upstream materials including bauxite mining, alumina refining, and production of anode materials and carbon anodes.

Excludes emissions associated with transportation, where possible. 

Excludes emissions associated with extraction and processing of raw materials. Excludes alumina refining and production of pre-baked carbon anodes (whether baked on- or off-site). 

Excludes emissions associated with transportation.

Includes emissions associated with extraction and processing or production of upstream materials including bauxite or other ores mining, alumina refining, and production of anode materials and carbon anodes.

Includes emissions associated with transportation.

Older versions of IAI guidance had more narrowly defined system boundaries.

Includes emissions associated with extraction and processing of raw materials and production of metal.

Includes emissions associated with transportation.

Includes emission associated with extraction and processing of raw materials and production of metal.

Includes emissions associated with transportation.

System boundaries (downstream products)

Primary aluminum, secondary aluminum, and certain downstream aluminum products. See investigation request letter in appendix A of this report for a full list.

Primary aluminum, secondary aluminum, and aluminum products. CBAM has more expansive coverage of downstream aluminum products than the USITC investigation.

The Good Practice Document only covers primary aluminum and its precursor products. Additional draft guidance on reporting carbon footprints of aluminum products when scrap or recycled material are incorporated would apply to both semifinished (e.g., sheet) and finished (e.g., cans) aluminum products.

Primary aluminum, secondary aluminum, generic and automotive extrusions, generic and automotive sheet, foil, and die castings.

Aluminum extrusions of varying finishes including mill finished, painted, anodized, thermally improved and painted, and thermally improved and anodized.

Allocation of facility-level emissions to products

USITC subdivides facility-level emissions into subprocesses; further divides subprocess-level emissions into unit-process level emissions based on “physical allocation” (i.e., by mass of output); and includes unit-process-level emissions within downstream emissions calculations where upstream products are internally consumed within the same facility.

Emissions are allocated using a similar approach to the USITC method, although product categories are broader. For facilities that do not externally ship any upstream products made on-site, a “bubble” approach can be used that avoids allocation of facility-level emissions into specific processes.

IAI guidelines rely on ISO 14044 / ISO 14067 allocation approaches. IAI recommends collecting input and output data separately at the subprocess level for different products. When this approach cannot be used, a physical allocation approach based on mass is generally the preferred way to allocate emissions across products.

Relies on ISO 14040/14044 standards. The approach attempts to avoid allocation by expanding system boundaries where possible.

Facility-level emissions are subdivided between product types using questionnaire data.

Scrap treatment

Scrap does not have embedded scope 3 emissions. The Commission’s questionnaire asked for data on the quantity and characteristics of scrap used in aluminum production (i.e., share of scrap that is post-consumer, runaround scrap) for supplemental analysis.

Scrap does not have embedded scope 3 emissions. Importers provide source installation’s quantity of scrap used in production, including the share of scrap that is pre-consumer.

No single approach recommended for determining scrap emissions, but treatment across different ISO standards Is described. Under all approaches, post-consumer scrap has no embedded scope 3 emissions. Disclosing the calculation for pre-consumer scrap emissions, and shares of pre- and post-consumer scrap used in production is good practice.

Scrap does not have embedded scope 3 emissions in the cradle-to-gate approach. The cradle-to-grave approach uses a modified substitution method, which allows for a scrap “credit” or “burden” depending on recycling rates. The questionnaire asked for information on the amount of scrap used that was pre- or post-consumer.

Scrap does not have embedded emissions in the cradle-to-gate approach. The cradle-to-grave approach allows for a scrap “credit” or “burden” based on net scrap output. The questionnaire asked for information on the amount of scrap used that was pre- or post-consumer.

Scope 3 emission requirements

Scope 3 emissions are generally calculated by multiplying activity data by emissions factors from default emissions factors collected by Commission (see appendix F in this report for more details). In the case of inputs of domestic primary aluminum, the supplier facility’s emissions data are used where possible.

Scope 3 emissions are generally calculated by multiplying activity data by emissions factors. Installations producing aluminum products are required to report emissions factors of inputs (“precursors”) produced off-site. These data may be collected directly from the precursor producers. If these emission data were not available, installations were also allowed to use default values provided under CBAM until July 2024. After July 2024, installations may only use those default values for 20 percent or less of their total embedded emissions.

Follows the GHG Protocol Corporate Value Chain (Scope 3) Accounting and Reporting Standard. User-defined “specific and verified” scope 3 emissions factors are recommended, though default emissions factors can be used in the event this information is not available. IAI provides a list of default emissions factors for material inputs in the aluminum value chain, gathered from various public sources.

The breakdown of scopes is done in compliance with the ISO 14044 standard. Scope 3 emissions are generally calculated by multiplying activity data by regional emissions factors. The LCA model uses aggregated survey results of inputs and outputs to find the average metal composition by product category.

Scope 3 emissions are generally calculated by multiplying activity data by emissions factors from default emissions factors mainly provided by Sphera and other sources. Where possible, location-specific emissions factors were used.