There is agreement on the need to establish common methodologies to measure the steel industry’s greenhouse gas emissions. This page provides related terminology and definitions.

For more information, please visit the Steel Standards Principle website.

Would you like to suggest another word or a correction? Contact us at ssp@worldsteel.org.

Alignment

Category: Alignment
Verb (to align): Identifying common building blocks of calculation methodology over different schemes, e.g., methodology decisions, defined data points.
Noun: The state of commonality between two approaches/systems.
Source: SSP

Alignment mechanism

Category: Alignment
A project or mechanism that aims to improve alignment between two or more standards, undertaken with agreement by the standard owners, or by an initiative aiming to influence the alignment of standards or data.
Source: SSP interoperability working group

Anthropogenic removals

Category: Reducing/ addressing impact
The withdrawal of greenhouse gases (GHGs) from the atmosphere as a result of deliberate human activities. These include enhancing biological sinks of CO2 and using chemical engineering to achieve long term removal and storage. Carbon capture and storage (CCS), which alone does not remove CO2 from the atmosphere, can help reduce atmospheric CO2 from industrial and energy-related sources if it is combined with bioenergy production (BECCS), or if CO2 is captured from the air directly and stored (DACCS).
Source: IPCC AR6

Avoided emissions

Category: Methodology – boundary
Synonyms: Scope 4
Emission reductions that occur outside of a product’s life cycle or value chain, but as a result of the use of that product. It compares the life cycle emissions from the product system of the studied object and the life cycle emissions from a reference product system.
Source:  WRI

Biogenic emissions

Category: Methodology-general
Synonyms: Biogenic carbon

Emissions derived from biomass, which is material of biological origin, excluding material embedded in geological formations and material transformed to fossilized material.
Note 1: Biomass includes organic material (both living and dead), e.g. trees, crops, grasses, tree litter, algae, animals, manure, and waste of biological origin.
Source: ISO 14067:2018

Biogenic removals

Category: Methodology-general
Applying CCS to remove biogenic carbon from industrial installations or processes.
Source: proposed

Book and Claim Chain of Custody

Category: CoC

Chain of custody model in which the certified material is completely decoupled from sustainability data. Certified and non-certified products flow freely throughout the supply chain, with volume reconciliation performed on an administrative basis.

Chain of custody model in which the administrative record flow is not necessarily connected to the physical flow of material or product throughout the supply chain (GHG Protocol, 2022b). Commonly referred to as “unbundled certificates” to support claims.
Source: SBTi/ISO 22085 – ISEAL – GHG Protocol

Carbon Dioxide Removal (CDR)

Category: Reducing/ addressing impact

Anthropogenic activities removing carbon dioxide (CO2) from the atmosphere and durably storing it in geological, terrestrial, or ocean reservoirs, or in products. It includes existing and potential anthropogenic enhancement of biological or geochemical CO2 sinks and direct air carbon dioxide capture and storage (DACCS) but excludes natural CO2 uptake not directly caused by human activities.
Source: IPCC AR6

Carbon-neutral steel

Category: “Low-carbon” steel
Synonyms: Net-zero steel

If a balance can be achieved between the greenhouse gases put into the atmosphere when producing steel and emissions taken out of the atmosphere by capturing and storing the residual CO2 through CCS from the specific production site in permanent sinks, the resulting steel can be referred to as carbon-neutral steel (or net-zero steel). The production of carbon-neutral steel may require permanent offsets in other sectors than the company’s value chain to achieve true neutrality, and it is important that if claims of carbon neutrality are made producers are transparent about boundaries, their accounting methodologies, and the quality and credibility of any offsets used.
Using external offsets outside of the company’s value chain to compensate for emissions from primary production is not enough to ensure that the product is carbon-neutral, due to the lack of control and certainty of the permanent nature of the offset as this may encourage companies to avoid making changes that truly reduce and avoid carbon emissions. Making claims of carbon-neutral steel using third party offsets hinders and delays the development of carbon-neutral or near-zero steel.

Note: where these definitions refer to ‘carbon’ in relation to emissions, this should be understood to include the emissions of all relevant GHGs, and not just emissions of CO2, unless otherwise stated.

Source: worldsteel  –  SBTi Corporate Net Zero Standard

Chain of custody

Category: CoC

Process by which inputs and outputs and associated information are transferred, monitored and controlled as they move through each step in the relevant supply chain.

The custodial sequence that occurs as ownership or control of the material supply is transferred from one custodian to another in the supply chain’. (Adapted from: WB, WWF Alliance for Forest Conservation and Sustainable Use, 2002).

Source: SBTi/ISO 22095 – ISEAL

Claims

Category: Reporting/ disclosure

Information communicated to customers, investors or other stakeholders about credentials, in the form of trademarks, certification marks, marketing materials, etc. (not only B2C).

Source: SSP

Clean steel

Category: “Low-carbon” steel

A technical expression used in the steel sector to refer to steels containing low levels of impurities, oxides, inclusions, or low or ultra-low level of carbon dissolved in the metal. The phrase is in common use, including by worldsteel’s 2004 ‘Study on Clean Steel’, and means something specific. Some other organisations use the term ‘clean steel’ in the context of low carbon emission steel.

Source: worldsteel

Climate Action

Category: Reducing/ addressing impact

Efforts to reduce or prevent greenhouse gas emissions and strengthen resilience and adaptive capacity to climate-induced impacts.

Source: IMAS

Climate change adaptation

Category: Reducing/ addressing impact

Process of adjusting to current or expected effects of climate change, and making changes to live with its impacts.

Source: IMAS

Climate change mitigation

Category: Reducing/ addressing impact

Efforts to reduce or prevent emission of greenhouse gases responsible for causing global warming and climate change.

Source: IMAS

Common reporting boundary

Category: Alignment

The specified unit processes, raw materials and energy source inputs included within the calculations from which emissions are reported, as adopted by multiple standards.

Source:  proposed

Common reporting point

Category: Alignment

The specified unit processes, raw materials and energy source inputs included within the calculations from which emissions are reported, as adopted by multiple standards.

Source:  proposed

Common reporting point

Category: Alignment

A point at which the emissions are reported, adopted by multiple standards; the denominator when reporting GHG or CO2-equivalent emissions. For example, per tonne steel, per m2 building use.

Source: worldsteel

Conversion tool

Category: Alignment

A rules-based mechanism aimed at enabling the translation of a data point calculated under one standard into a second data point that is compliant with another standard.

Source: SSP interoperability working group

Crude steel

Category: Methodology – boundary

Steel in the first solid state after melting, suitable for further processing or for sale (therefore includes secondary metallurgy and casting).

Source: worldsteel

Data quality

Category: Methodology – data

The quality of the data with respect to temporal, geographical and technological representativeness. Indicators can also include the percentage of primary data in the overall share of GHG emissions. A data quality rating can be developed based on these aspects and be qualitative and/or quantitative.

Source: proposed

Decarbonisation

Category: Reducing/ addressing impact

The measures through which an entity, industry, or sector reduces or avoids its GHG emissions. Decarbonisation on a global level refers to the overall reduction of GHG emissions.

Source: VCMI

Emission factors

Category: Methodology – data

See “Secondary data”, typically referring to CO2 or GHG emissions.

Empirical

Category: Methodology – data

Data that is gathered through observation, experimentation, or experience.

Source: proposed

End-of-life scrap

Category: Scrap

Synonyms: Post-consumer scrap

Scrap from after the end-of-life of final products.

Source: ISO 20915: 2018

Environmental Attribute Certificate

Category: Reporting/ disclosure

Instrument that certifies and communicates the environmental and/or climate-related attributes associated with commodities, activities or projects. The term EAC is also used to refer to Energy Attribute Certificates.

Source: SBTi

Environmental Product Declaration (EPD)

Category: Reporting/ disclosure

Synonyms: Type III environmental declaration

Environmental label or declaration providing quantified environmental data using predetermined parameters and, where relevant, additional environmental information that may be quantitative or qualitative. Typically used in the construction sector with specific PCR. Standards ISO 21930 and EN 15804 are relevant.

Source:  ISO 14025:2006

Equivalency claim

Category: Alignment

An authorised statement that a value obtained under a credible, independently assured interoperability mechanism fulfils the relevant requirements of the standard to which equivalency is claimed.

Source: SSP interoperability working group

External scrap

Category: Scrap

Scrap provided from outside of the steelworks, including manufacturing scrap and end-of-life scrap.

Source: ISO 20915: 2018

GHG emissions intensity

Category: Methodology – boundary

tonnes GHG emissions per tonne of crude steel production, including scopes 1, 2 and 3. Can be expressed as GWP100 or GWP20.

Source: worldsteel

GHG Reduction Certificates

Category: CoC

Output from pooling GHG emission reductions from emission reduction projects implemented by companies and assigning these cumulative emission reductions to products.

Source: worldsteel

Green steel

Category: “Low carbon” steel

Green steel is being used and interpreted by many different parties to mean different things, often in the context of marketing new more environmentally conscious products. It has been used to refer to steel manufactured using breakthrough technology, steel produced from scrap, steel produced from renewable energy, reused and remanufactured steel, and conventional steel with emissions offset through the retirement of carbon units or allowances. Often the term is used in relation to the carbon emissions only (see low carbon steel) and is therefore only a subset of environmental performance. This is not a recommended term and given this inherent lack of clarity, diversity of meanings and focus on carbon emissions, it will likely be difficult agreeing on one unified definition of green steel.

Source: worldsteel

Flat products

A type of finished rolled steel product like steel strip and plate.

Harmonisation

Category: Alignment

The process of creating common rules in different methodologies to create consistency and compatibility.

Source: SSP

Home scrap

Category: Scrap

Scrap from a downstream steel production process within the steelworks (e.g., rolling, coating) that is returned to steel making processes (e.g., BOF or EAF).

Source: ISO 20915: 2018

Input

Category: CoC

Life Cycle Assessment, with Chain of Custody Context: material, product, or energy flow that enters a unit process

Note 1 to entry: Products and materials include raw materials, intermediate products and co-products

Note 2 to entry: In the context of chain of custody models, inputs with associated information enter a unit process within an organisation within the chain of custody.
Note 3 to entry: Input can have associated information, such as specified characteristics.

Source: ISO 14040: 2006, ISO 22095

Insetting

Category: Reducing/ addressing impact

Purchasing and retiring carbon credits and/or Environmental Attribute Certificates that relate to activities that occur within a company’s value chains as a way of targeting emissions within specific categories, e.g. steel related emissions.

Source:  SBTi

Installation

Category: Methodology – boundary

See site.

Source: proposed

Internal scrap

Category: Scrap

Scrap from a crude steel making unit process that is then recycled within the same unit process [e.g., basic oxygen furnace (BOF) or electric arc furnace (EAF)].

Source: ISO 20915: 2018

Interoperability

Category: Alignment

The state of measurement methodologies, or thresholds, that are seen as sufficiently aligned to enable conversion between two or more schemes. It requires a mechanism to enable operation and a governance system to oversee this.

Source: SSP

Interoperability framework

Category: Alignment

A set of terms agreed between the owners of two or more standards that supports interoperability, consisting of both technical components and the necessary governance and supporting terms needed for the credible implementation of interoperability.

Source: SSP

Interoperable; Interoperability

Category: Alignment

The ability of a system to work with other systems, specifically with the aim of exchanging and making use of information and data.
In the context of methodology harmonization, the term interoperable sets out the ambition that emission accounting requirements in CFP/LCA-based methodologies could be made less flexible and that different methodologies could be harmonized, making the resulting data in CFPs/LCAs comparable.

Note: IDDI refers to product category rules and EPDs.

Source: IDDI from the IEA report

Life Cycle Assessment (LCA)

Category: Methodology-general

Compilation and evaluation of the inputs, outputs and the potential environmental impacts of a product system throughout its life cycle.

Source: ISO 14040: 2006

Life Cycle Inventory (LCI)

Category: Methodology-general

Phase of life cycle assessment involving the compilation and qualification of inputs and outputs for a product throughout its life cycle.

Source: ISO 14040:2006

Low-carbon (emission) steel

Category: “Low carbon” steel

Steel manufactured using technologies and practices that result in significantly lower GHG emissions than conventional production.
Note: where these definitions refer to ‘carbon’ in relation to emissions, this should be understood to include the emissions of all relevant GHGs, and not just emissions of CO2, unless otherwise stated.

Source: worldsteel

Low emissions

Category: “Low carbon” steel

The “low-emissions” designation recognizes substantial progress and emissions reductions towards the ultimate near-zero goal while not fully achieving it. Given that it will take time for the full market to transition to near-zero emissions technologies, policies that in parallel incentivise scale-up of increasingly lower-emission technologies are also valuable.

Source: IEA

Manufacturing scrap

Category: Scrap

Scrap from the manufacturing processes of final products, such as automobiles and buildings.

Source: ISO 20915: 2018

Market-based accounting

Category: Methodology – data

Reflects emissions from electricity that companies have purposefully chosen (or their lack of choice). It derives emission factors from contractual instruments, which include any type of contract between two parties for the sale and purchase of energy bundled with attributes about the energy generation, or for unbundled attribute claims. These instruments can include energy attribute certificates (RECs, GOs, etc.), direct contracts (for both low-carbon, renewable, or fossil fuel generation), supplier-specific emission rates, and other default emission factors representing the untracked or unclaimed energy and emissions (termed the “residual mix”).

Source: GHG Protocol Scope 2 Guidance

Mass Balance

Category: CoC

A general accounting approach that ensures the input mass balances with the output mass within a given period, following the law of conservation of mass.

Mass Balance Chain of Custody

Category: CoC

Chain of custody model in which materials or products with a set of specified characteristics are mixed according to defined criteria with materials or products without that set of characteristics.

Additionally from ISEAL: Mass balancing can be carried out over different systems levels, e.g. batch-level, site-level or group-level, and may occur at several points along the supply chain.

Source: SBTi/ISO 22095 – ISEAL

Measurement based

Category: Methodology – data

Evidence based data

Near Zero (emissions) steel

Category: “Low carbon” steel

Steel produced with the minimum possible level of GHG emissions for a given technology, and whose production is compatible with an energy system at net zero emissions. IEA has proposed threshold levels of GHG intensity that meet this definition in its paper ‘Definitions for near-zero and low emissions steel and cement, and underlying emissions measurement methodologies’ (2024).

Common definitions for “near zero emission steel” can establish a shared vision of the future for key production processes in the steel industry. The definitions should be stable, absolute and ambitious, and compatible with a trajectory that reaches net zero emissions from the global energy system by mid-century.

Source: MWS – IEA

Near-zero emissions

Category: “Low carbon” steel

“Near-zero emissions” is specifically reserved for technologies that are already compatible with an energy system at net zero emissions. Distinctive recognition of such performance is critical, already today, particularly given the higher risks and costs that come with development and early deployment of innovative technologies. Incentivizing these technologies now can help kick-start market uptake, paving the way to eventual widespread diffusion.

Source: IEA

Net-zero CO2 emissions

Category: “Low carbon” steel

Condition in which anthropogenic carbon dioxide (CO2) emissions are balanced by anthropogenic CO2 removals over a specified period. Carbon neutrality and net zero CO2 emissions are overlapping concepts. The concepts can be applied at global or sub-global scales (e.g., regional, national and sub-national). At a global scale, the terms carbon neutrality and net zero CO2 emissions are equivalent. At sub-global scales, net zero CO2 emissions is generally applied to emissions and removals under direct control or territorial responsibility of the reporting entity, while carbon neutrality generally includes emissions and removals within and beyond the direct control or territorial responsibility of the reporting entity.

Source: IPCC AR6

Net-zero GHG emissions

Category: “Low-carbon” steel

Condition in which metric-weighted anthropogenic greenhouse gas (GHG) emissions are balanced by metric-weighted anthropogenic GHG removals over a specified period. The quantification of net zero GHG emissions depends on the GHG emission metric chosen to compare emissions and removals of different gases, as well as the time horizon chosen for that metric.

Source: IPCC AR6

Net-zero steel

Category: “Low carbon” steel

Near-zero steel (CF) for which any residual, unavoidable GHG emissions have been offset.

Source: MWS

Net-zero (emission) steel

Category: “Low carbon” steel

See carbon-neutral steel.

Source: worldsteel

Offsetting

Category: Reducing/ addressing impact

Purchasing carbon credits from activities outside of a company’s value chain as a substitute for abating emissions within its value chain.

Source:  SBTi

Output

Category: CoC

Life Cycle Assessment, with Chain of Custody Context: material, product, or energy flow that leaves a unit process
Note 1 to entry: Products and materials include raw materials, intermediate products, co-products, and releases.
Note 2 to entry: In the context of chain of custody models, output is material or a product which leaves a unit process within an organisation within the chain of custody.

Source: ISO 14044: 2006, mods to note 2

Physical connection

Category: CoC

Physical connection means the production chain is connected to the emission reduction projects, regardless of whether the product is produced at a single site or across multiple sites.

Source: worldsteel

Physical segregation 

Category: CoC

Chain of custody model in which materials or products with a set of specified characteristics (i.e. certified products) are physically separated from materials or products without that set of characteristics (i.e. non-certified products).

Source: ISEAL

Post-consumer recycled content (steel)

Category: Scrap

The proportion of the ferrous content of crude steel that is derived from end-of-life scrap.

Source: proposed

Pre-consumer recycled content (steel)

Category: Scrap

The proportion of the ferrous content of crude steel that is derived from pre-consumer scrap, which is the total of home scrap and manufacturing scrap. Note: internal scrap does not contribute to the pre-consumer recycled content of steel.

Source: proposed

Pre-consumer scrap

Category: Scrap

Includes home scrap, internal scrap and manufacturing scrap. The scrap generated during the production of a product before it is used by a consumer.

Source: proposed

Primary data

Category: Methodology – data

Synonyms: Foreground data

Quantified value of a process or an activity obtained from a direct measurement or a calculation based on direct measurements.
Note to entry: Primary data can include GHG emission factors and/or GHG activity data (defined in ISO 14064-1:2006, 2.11).

Source: ISO 14067:2018 (modified)

Process

Category: Methodology – boundary

Synonyms: unit process

A distinct part of the steel making process, e.g. coke ovens, sinter plant, blast furnace etc.

Source: worldsteel

Product Category Rules (PCR)

Category: Reporting/ disclosure

Set of specific rules, requirements and guidelines for developing Type III environmental declarations (EPDs) for one or more product categories.

Source:  ISO 14025:2006

Recognition

Category: Alignment

Acceptance of data or claims made on the basis of one scheme by another scheme, such that they are regarded as providing a means to compliance with its requirements.

Source: SSP

Recycled content (steel)

Category: Scrap

The proportion of the ferrous content of crude steel that is derived from home scrap, manufacturing scrap and end-of-life scrap.
Note: Internal scrap does not contribute to the recycled content of steel.

Source: proposed

Scope 1 emissions

Category: Methodology – boundary

A reporting company’s direct GHG emissions from sources that are owned or controlled by the reporting company.

Source: GHG Protocol

Scope 2 emissions

Category: Methodology – boundary

A reporting company’s indirect emissions associated with the generation of electricity, heat, or steam purchased or otherwise brought into the boundary and consumed by the company. Scope 2 emissions physically occur at the facility where electricity, heat, or steam is generated.

Source: GHG Protocol

Scope 3 emissions – downstream

Category: Methodology – boundary

A reporting company’s indirect emissions (not included in Scope 2) that occur in the value chain of the reporting company after leaving the Scope 1 boundary of the company’s facilities. Scope 3 downstream categories include product distribution, processing of sold products, use of sold products, and end-of-life treatment of sold products.

Source: GHG Protocol Technical Guidance for Calculating Scope 3 Emissions

Scope 3 emissions – upstream

Category: Methodology – boundary

A reporting company’s indirect emissions (not included in Scope 2) that occur in the value chain of the reporting company prior to reaching the Scope 1 boundary of the company’s facilities. Scope 3 upstream categories include purchased goods and services, capital goods, fuel and energy–related activities, transportation, and waste generated in operations.

Source: GHG Protocol Technical Guidance for Calculating Scope 3 Emissions

(Ferrous) scrap

Category: Scrap

Iron and steel material in metallic form that is recovered in multiple life cycle stages, including steel production processes, the manufacturing processes of final products and the end-of-life of final products, and is recycled as a raw material for steel production.

Source: ISO 20915: 2018

Secondary data

Category: Methodology – data

Synonyms: Background data

Data which do not fulfil the requirements for primary data.
Note 1 to entry: Secondary data can include data from databases and published literature, default emission factors from national inventories, calculated data, estimates or other representative data, validated by competent authorities.
Note 2 to entry: Secondary data can include data obtained from proxy processes or estimates.

Steel scrap is one of the steel industry’s most important raw materials. It comes from all steel-containing products that reach the end of their life (post-consumer scrap), from demolished structures to end of life vehicles, packaging, white goods and machinery, and the yield losses in the steelmaking and manufacturing processes (pre-consumer scrap). It can also include iron scrap. All steel can be recycled into new steel. All new steel contains some steel scrap.

Source:  ISO 14067:2018

Site

Category: Methodology – boundary

A physical location on which steel making or processing operations are carried out.

Source: worldsteel

Site-specific data

Category: Methodology – data

Synonyms: Facility-specific data

Primary data obtained within the product system.
Note 1 to entry: All site-specific data are primary data but not all primary data are site-specific data because they may be obtained from a different product system.
Note 2 to entry: Site-specific data include GHG emissions from GHG sources as well as GHG removals by GHG sinks for one specific unit process within a site.

Source:  ISO 14067:2018

Specific

Category: Methodology – data

See ‘Empirical’

Source: proposed

SSP aim

Category: Alignment

Alignment on different building blocks with the help of interoperability to reach harmonisation.

Source: proposed

Standard

Category: Methodology-general

A document, established by consensus and approved by a recognized body, that provides, for common and repeated use, rules, guidelines or characteristics for activities or their results, aimed at the achievement of the optimum degree of order in a given context.

Source: ISO

Traceability 

Category: CoC

The ability to verify the history, location, or application of an item by means of documented recorded identification.

Source: ISEAL

Zero-carbon (emission) steel

Category: “Low carbon” steel

To be truly zero-carbonsteel would need to be produced without any CO2 emissions at all. This is a very high bar to reach, and it is difficult to conceive of a production technology that could achieve this in the short term.

Source: worldsteel