Cradle-to-Gate Product Carbon Footprint
A product carbon footprint lives or dies on one decision made before a single emission factor is multiplied: where the system boundary stops. Draw it at the factory gate and you have a cradle-to-gate figure that suppliers can exchange and customers can roll into their Scope 3. Draw it anywhere else, or draw it inconsistently, and the number is unverifiable and incomparable.
ISO 14067 is the standard that makes the boundary, the biogenic carbon, and the allocation defensible — and this is how each step is executed.
A cradle-to-gate product carbon footprint under ISO 14067 quantifies GHG emissions from raw-material extraction (A1), transport to the manufacturer (A2) and production (A3), expressed as CO2e per declared unit. It excludes distribution, use and end-of-life.
What Cradle-to-Gate Means
A product carbon footprint (PCF) is the sum of greenhouse-gas emissions and removals over a defined portion of a product’s life cycle, expressed as carbon dioxide equivalent (CO2e) per declared or functional unit. ISO 14067:2018, Greenhouse gases — Carbon footprint of products — Requirements and guidelines for quantification, is the international standard that governs how that figure is built. The boundary chosen determines which life-cycle stages are counted, and cradle-to-gate is the boundary that stops at the point the finished product leaves the manufacturer’s gate.
In the EN 15978 / EN 15804 modular convention used across the carbon-accounting field, cradle-to-gate is modules A1–A3: raw-material supply (A1), transport of those materials to the factory (A2), and manufacturing (A3). It is also called a “partial” carbon footprint in ISO 14067 terms, because it deliberately omits later stages.
The four PCF boundary types
| Boundary | Modules covered | What it answers | Typical use |
|---|---|---|---|
| Cradle-to-gate | A1–A3 (extraction → manufacture) | Embodied carbon of the product as it leaves the factory | B2B supplier-to-customer exchange; Scope 3 Category 1 inputs; intermediate goods |
| Cradle-to-grave | A1–A3 + A4–A5 + B + C (full life cycle) | Total life-cycle footprint including use and disposal | Consumer products; whole-life building assessment; eco-design trade-offs |
| Gate-to-gate | A3 only (manufacture) | Emissions of one process step in isolation | Process improvement; a single tier within a longer chain |
| Cradle-to-cradle | A1–A3 + C + D (with recovery credit) | Footprint net of end-of-life recovery and recycling benefit | Circular-economy claims; products with established recovery loops |
Why cradle-to-gate dominates B2B accounting
A manufacturer controls and can measure everything up to its own gate; it generally cannot measure how a customer transports, uses or disposes of the product. Cradle-to-gate is therefore the boundary at which a supplier can produce a primary-data-backed number and hand it on. The receiving organisation treats that figure as the emission factor for the purchased good and folds it into Scope 3 Category 1. This supplier-to-customer chaining is the mechanism behind the WBCSD Pathfinder Framework and the entire primary-data movement in corporate value-chain accounting — and it only works if every participant draws the gate in the same place.
Provider directory
Now it has to survive the next design change.
See who does this work. Every listing names the standards it works to, and paid placements are labelled. Including Circular Ecology and Enviropass Consulting.
Browse 4 embodied carbon & LCA providers →Do this work? A listing is US$390 a year. Get listed →
Governing Standards: The ISO 14067 Stack
ISO 14067 does not stand alone. It is a carbon-specific application layer on top of the general life-cycle-assessment standards, and it sits alongside two parallel frameworks that quantify the same thing under different governance. Understanding which document supplies which rule prevents the most common methodological confusion in PCF work.
| Layer | Standard | What it supplies |
|---|---|---|
| Carbon-specific quantification | ISO 14067:2018 | The PCF-specific requirements: GWP application, biogenic carbon treatment, land-use-change accounting, the comparability rules, and the partial-vs-full footprint distinction. |
| General LCA framework | ISO 14040 / ISO 14044 | The four-phase LCA method, the allocation hierarchy, cut-off criteria, data-quality requirements, and the critical-review rules. ISO 14067 inherits all of these. |
| EPD / Type III declaration | ISO 14025 + EN 15804 | Product Category Rules (PCRs) and the modular A/B/C/D life-cycle structure that makes declarations comparable within a product category. |
ISO 14067 over ISO 14040/14044
The ISO 14040 series defines life-cycle assessment for any impact category — acidification, eutrophication, water use, climate change, and others. ISO 14067 takes the climate-change category alone, fixes the impact-assessment method to 100-year global warming potentials from the IPCC, and adds the carbon-specific rules that generic LCA leaves open: how to treat biogenic CO2 uptake and release, how to amortise emissions from direct land-use change, and when a PCF may be compared with another. Everything procedural — goal and scope definition, inventory construction, allocation, interpretation — is inherited unchanged from ISO 14044.
ISO 14067 vs the GHG Protocol Product Standard
The GHG Protocol Product Life Cycle Accounting and Reporting Standard quantifies the same quantity — cradle-to-gate or cradle-to-grave product emissions — under a different governing body. The two are broadly convergent: both require the four LCA phases, both use IPCC GWP-100, both demand the biogenic and land-use-change rules. The practical differences are in emphasis: the GHG Protocol Product Standard places heavier weight on inventory uncertainty assessment and on the requirement to follow a published PCR where one exists, while ISO 14067 is more prescriptive on the comparability and critical-review conditions. A study can usually be designed to satisfy both; declare which standard governs and follow its specific rules where they diverge.
Where EN 15804, PEF and Pathfinder sit
Three adjacent frameworks reuse the cradle-to-gate machinery. EN 15804 is the construction-product Environmental Product Declaration standard whose A1–A3 module definitions this article uses; the EU Product Environmental Footprint (PEF) is the European Commission’s harmonised multi-impact method with its own category rules; and the WBCSD Pathfinder Framework is the data-exchange protocol that standardises how a cradle-to-gate PCF is transmitted from supplier to customer. All three depend on the same ISO 14040/14044 + ISO 14067 foundation; they differ in scope of impact categories, sector specificity, and the governance attached to comparability claims.
The Four LCA Phases for a Carbon Footprint
ISO 14044 structures every LCA — and therefore every ISO 14067 PCF — into four iterative phases. They are not strictly sequential: interpretation feeds back into scope, and inventory gaps often force the goal to be refined. Executed for a cradle-to-gate carbon footprint, they read as follows.
1 · Goal & Scope Definition
Fix the intended application and audience, the functional or declared unit, the cradle-to-gate boundary, the cut-off criteria, the allocation approach, the GWP basis (AR6 GWP-100), and the data-quality requirements. Every later choice traces back to decisions recorded here.
2 · Inventory Analysis (LCI)
Compile the inputs and outputs of every unit process inside the boundary — energy, materials, transport, direct process emissions — scaled to the declared unit. Primary (measured) data is used for the foreground; secondary database data fills the background.
3 · Impact Assessment (LCIA)
Multiply each inventory flow by its 100-year GWP to convert it to CO2e, then sum. For a carbon footprint the impact category is fixed to climate change, so this phase is a single characterisation step rather than a multi-category model.
4 · Interpretation
Identify the significant contributors, test sensitivity to the key assumptions (allocation, biogenic treatment, secondary-data choices), check completeness and consistency, and state the limitations. This is where the number becomes defensible or is sent back for refinement.
Defining the System Boundary
The system boundary is the set of unit processes included in the study. For cradle-to-gate it runs from the extraction of raw materials to the point the finished product leaves the manufacturing site. Getting it explicit — process by process — is the single highest-leverage step in a PCF, because an omitted process silently understates the footprint and an over-broad boundary makes the number incomparable with other gate figures.
The unit-process map (A1–A3)
| Module | Unit processes inside the boundary | Principal inputs counted | Principal emission sources |
|---|---|---|---|
| A1 — Raw material supply | Extraction and processing of all input materials; production of purchased intermediates; recycled-content input processing | Ore, biomass, chemicals, purchased components, recycled feedstock | Upstream extraction and refining emissions, embedded in supplier or database factors |
| A2 — Transport to manufacturer | Inbound logistics of every A1 input from supplier gate to factory gate | Road, rail, sea and air freight; distances and modes | Combustion of transport fuels (tank-to-wheel) plus upstream fuel supply where included |
| A3 — Manufacturing | All on-site production: forming, assembly, finishing, on-site energy generation, internal logistics, on-site waste treatment | Purchased electricity and heat, on-site fuels, process chemicals, packaging applied at the gate | On-site combustion (Scope 1), purchased energy (Scope 2), direct process emissions |
Two boundary conventions are worth stating explicitly because they are routinely mishandled. First, capital goods — the factory building, machinery, and tooling — are generally excluded from a product-level cradle-to-gate PCF under most PCRs, on the basis that their emissions amortised across lifetime production volume are immaterial; this exclusion must be declared, not assumed. Second, packaging applied at the manufacturing gate (primary packaging that ships with the product) sits inside A3, whereas distribution packaging added later belongs to A4 and is therefore outside cradle-to-gate.
Cut-off criteria
ISO 14044 requires the cut-off criteria — the threshold below which an input or process may be excluded — to be defined in the goal and scope and applied consistently. Common practice expresses cut-off on mass, energy and environmental-significance bases (for example, “processes contributing less than 1% of cumulative mass and less than 1% of cumulative energy are excluded, provided no single excluded flow is environmentally significant”). The environmental-significance test is the one that matters most: a flow can be a fraction of a percent by mass yet dominate the carbon footprint (a fluorinated process gas, for instance). Never cut off on mass alone. State the criteria, apply them uniformly, and document what was excluded.
What stays out of cradle-to-gate
- A4 — Distribution to the customer or point of sale (outbound transport, distribution packaging).
- A5 — Installation where applicable (construction products).
- B1–B7 — Use stage: operational energy and water, maintenance, repair, replacement.
- C1–C4 — End-of-life: deconstruction, transport to disposal, waste processing, final disposal.
- D — Benefits beyond the boundary: reuse, recovery and recycling credits, always reported separately and never netted into A1–A3.
Allocation: The ISO 14044 Hierarchy
Allocation is the apportioning of a shared process’s emissions among the multiple products it yields. A refinery produces fuels and petrochemical feedstocks from one crude stream; a dairy yields milk, cream and whey; a sawmill produces boards and sawdust. The total process emissions are real, but only a fraction belongs to the product under study. How that fraction is determined is the second-most-litigated choice in a PCF after the boundary, because the allocation method can swing the result substantially and there is rarely one objectively correct answer.
ISO 14044 §4.3.4 imposes a strict decision order. It must be worked top-down: a lower step is used only when every step above it has been shown to be infeasible.
| Step | Rule | How it applies in practice |
|---|---|---|
| 1 — Avoid | Wherever possible, avoid allocation by subdividing the multi-output process into sub-processes, or by expanding the system boundary to include the additional functions of the co-products. | Sub-division needs separable sub-process data. System expansion (substitution) credits the co-product with the emissions of the conventional product it displaces — powerful but data-hungry and sensitive to the chosen marginal substitute. |
| 2 — Physical relationship | Where allocation is unavoidable, partition inputs and outputs according to the underlying physical relationship between the products (mass, energy content, or another physical property that reflects how the process responds to a change in output). | Mass allocation for co-products of similar character; energy allocation for fuels and energy carriers; a physical causal property where one exists. |
| 3 — Other relationship | Where no physical relationship can be established, allocate in proportion to another relationship — most commonly economic value (market price of each co-product). | Economic allocation is the common fallback when products are physically dissimilar (e.g. a high-value extract and a low-value residue). It introduces price volatility into the carbon result, which must be disclosed. |
Co-products and recycling: cut-off vs avoided burden
Recycling forces a specific allocation decision: how to split the burdens and benefits of a material that crosses two product life cycles. Two conventions dominate. Under the cut-off (recycled-content) approach, the recycling process burden is assigned to the system that uses the recycled material as input, and the system that discards the material to recycling carries none of the downstream benefit — a clean, conservative split favoured by many PCRs. Under the avoided-burden (end-of-life recycling) approach, the system that supplies material to recycling is credited with displacing virgin production. The choice materially changes the A1 figure for any product with recycled content and must be fixed in scope and applied consistently; mixing the two within one study double-counts the benefit.
Biogenic Carbon and Land-Use Change
This is the content ISO 14067 adds over generic LCA, and the area where PCFs most often diverge from each other for the same product. Biogenic carbon — carbon that was in the atmosphere, was taken up by biomass, and may be released again — is accounted on a separate track from fossil carbon, and the bookkeeping conventions are specific.
The −1/+1 uptake convention
Biogenic CO2 is tracked as an uptake at the point biomass grows (a negative emission, conventionally −1 kg CO2 per kg CO2 sequestered) and a release when that biomass is combusted, decomposed or otherwise oxidised (a positive emission, +1). For a product where all biogenic carbon taken up is released within the boundary, the two cancel to a net zero biogenic contribution. The uptake is computed stoichiometrically: each kilogram of biogenic carbon corresponds to 3.667 kg of CO2 [GreenCalculus lca.biogenic.uptake.co2_per_kg_biogenic_carbon · ISO 14067 2018 · v2026.203] (the 44/12 molecular-mass ratio). Biogenic and fossil CO2 are reported as separate line items in an ISO 14067 PCF — never silently merged — so that a reader can see the carbon balance rather than a single netted figure.
Biogenic methane is the exception that breaks the clean balance. When biogenic carbon is released as CH4 rather than CO2 — in landfill, anaerobic digestion or enteric processes — it leaves the boundary as a more potent gas than the CO2 that was taken up, so the uptake and release do not cancel. Biogenic methane is characterised at its own GWP-100 value of 27 [GreenCalculus gwp.CH4_biogenic.ar6_100 · IPCC AR6] (AR6), distinct from fossil methane at 29.8 [GreenCalculus gwp.CH4_fossil.ar6_100 · IPCC AR6 WGI Ch 7 Table 7.SM.7 (2021) — AR6 GWP-100], and the residual is a real positive contribution to the footprint.
Direct land-use change amortisation
Where the product’s biomass inputs are associated with direct land-use change — conversion of forest or grassland to cropland within a defined historical window — the one-off carbon-stock loss is amortised across the production from that land. The standard amortisation period is 20 years, applied as 5% [GreenCalculus lca.biogenic.luc.amortization_per_annum_pct · ISO 14067 2018] of the conversion emissions per year. This prevents a single conversion event from being charged entirely to one year’s harvest, and it means a commitment to halt future conversion does not retroactively zero out land-use-change emissions still inside the 20-year window.
Carbon storage and delayed emissions
Where biogenic carbon is genuinely stored in the product beyond the assessment period — durable timber in a building, for example — ISO 14067 permits a carbon-storage credit only where the storage is demonstrably permanent over a defined horizon. The conventional permanence threshold is 100 years [GreenCalculus lca.biogenic.carbon_storage.permanence_required_years · ISO 14067 2018]; storage shorter than this is treated as a timing difference, not a removal. Delayed-emission and temporary-storage credits are contentious and PCR-dependent; declare the method and the horizon, and do not claim storage that the product’s realistic end-of-life does not support.
Data Quality and the Primary/Secondary Split
ISO 14044 requires the data-quality requirements to be specified in scope and assessed in interpretation. For a carbon footprint the practical distinction is between primary data — measured at the specific process, supplier-specific, time-specific — and secondary data drawn from LCI databases or generic factors. A defensible PCF uses primary data for the foreground processes the reporting organisation controls and the highest-quality available secondary data for the background.
| Data tier | Source | Use in a PCF | Quality signal |
|---|---|---|---|
| Supplier-specific primary | Measured production data from the actual supplier of the actual input, exchanged as a cradle-to-gate PCF (Pathfinder) | Foreground inputs; the target state for material A1 flows | Highest — maps to PCAF data-quality Score 1 when used as a Scope 3 factor |
| Site-specific primary | The reporting organisation’s own metered energy, fuel and process data for A3 | Manufacturing module; almost always available and expected | Highest for foreground |
| Process-average secondary | LCI databases — ecoinvent, ÖKOBAUDAT, ADEME Base Empreinte — representative of a technology and region | Background processes the organisation cannot measure | Good, where geography and technology match |
| Spend-based secondary | Environmentally-extended input-output factors (kg CO2e per unit of spend) | Last-resort screening only; a fallback when no PCF and no representative LCI factor exists | Lowest — PCAF Score 4/5; see the spend-based methodology |
The data-quality hierarchy is also the improvement roadmap. A first-pass PCF built on database and spend-based factors is legitimate as a screening study, provided the secondary-data reliance is disclosed and a plan exists to replace material background flows with supplier-specific primary PCFs over successive cycles. The Pathfinder exchange exists precisely to make that replacement scalable.
GWP Basis and CO2e Aggregation
The impact-assessment phase converts each inventory gas to CO2e by multiplying its mass by its 100-year global warming potential. ISO 14067 ties the characterisation to the most recent IPCC assessment; current corporate and product accounting uses IPCC AR6 GWP-100 values. The principal non-CO2 gases in a manufacturing PCF are fossil methane and nitrous oxide.
Two basis rules carry through to the result. First, do not mix assessment reports within one footprint: every gas in a single PCF is characterised on the same basis (AR6 throughout), because the GWP values shifted between AR5 and AR6 and a mixed-basis total is not internally consistent. Second, where a background factor is sourced from a database published on an AR5 basis (some DEFRA-derived factors carry AR5 internally by convention), that asymmetry is disclosed per line item rather than silently blended. The CO2e total is the sum of fossil CO2, fossil CH4 × 29.8 [GreenCalculus gwp.CH4_fossil.ar6_100], N2O × 273 [GreenCalculus gwp.N2O.ar6_100 · IPCC AR6 WGI Ch 7 Table 7.SM.7 (2021) — AR6 GWP-100], any other characterised gases, plus the separately-reported biogenic line.
Worked Example: Cradle-to-Gate PCF of a Coated Steel Component
A complete cradle-to-gate calculation for one declared unit, with every input, factor and arithmetic step shown. The product is a fictional coated steel bracket; the declared unit is one finished bracket of 2.0 kg net mass. The emission factors below are illustrative, chosen to demonstrate the method — a real study draws A1 factors from a supplier PCF or a representative LCI database (ecoinvent, ÖKOBAUDAT), A2 from measured logistics, and A3 from the site’s own metered energy. All arithmetic is hardcoded as an audit record at the review date of this methodology.
| Module | Flow | Quantity | Illustrative factor | CO2e (kg) |
|---|---|---|---|---|
| A1 | Primary steel (80% of input) | 1.760 kg | 2.45 kg CO2e/kg | 4.3120 |
| A1 | Recycled steel (20%, cut-off basis) | 0.440 kg | 0.70 kg CO2e/kg | 0.3080 |
| A1 | Coating (epoxy powder) | 0.060 kg | 5.10 kg CO2e/kg | 0.3060 |
| A2 | Inbound road freight | 2.260 kg × 320 km = 0.7232 t·km | 0.111 kg CO2e/t·km | 0.0803 |
| A3 | Electricity (forming + coating) | 0.95 kWh | 0.207 kg CO2e/kWh | 0.1967 |
| A3 | Natural gas (curing oven) | 0.42 kWh | 0.183 kg CO2e/kWh | 0.0769 |
| A3 | Primary packaging | 0.030 kg | 0.90 kg CO2e/kg | 0.0270 |
The input mass exceeds the 2.0 kg declared net mass because manufacturing scrap (0.26 kg, recovered to recycling under the cut-off convention and therefore carried at its A1 burden) is part of the material drawn through the gate. Summing the modules:
| Module | Sub-total (kg CO2e) | Share of A1–A3 |
|---|---|---|
| A1 — Raw material supply | 4.9260 | 92.0% |
| A2 — Transport to manufacturer | 0.0803 | 1.5% |
| A3 — Manufacturing | 0.3006 | 5.6% |
| Cradle-to-gate total (A1–A3) | 5.3069 | 100% |
The declared cradle-to-gate footprint is 5.31 kg CO2e per bracket (5.3069 kg, rounded to three significant figures for the declaration). The module composition is shown below — and it carries the single most important interpretation finding for steel-based products.
Raw materials dominate at 92% of the cradle-to-gate footprint, which is typical for metal and mineral products and is the reason A1 data quality matters more than any other single choice. Replacing the illustrative database steel factor with a supplier-specific primary PCF would move the result far more than any plausible refinement to A2 or A3. The interpretation phase would flag the primary-steel factor as the dominant sensitivity and the priority for primary-data substitution in the next cycle.
Biogenic note: this product contains no biomass-derived carbon, so the biogenic line is zero and the fossil CO2e total above is the full footprint. A product with biogenic inputs (timber, bio-based polymer, paper packaging) would carry a separate biogenic line — uptake at −44/12 per kg biogenic carbon, release on oxidation — reported alongside, not inside, the fossil total.
Comparability, PCRs and the Functional-Unit Trap
The most misunderstood rule in ISO 14067 is that two PCFs are not comparable merely because both are cradle-to-gate and both are expressed in kg CO2e. Comparability requires that both studies used the same functional unit, the same system boundary, the same cut-off criteria, the same allocation approach, equivalent data quality, and — where one exists — the same Product Category Rule. Absent those conditions, two numbers for “the same” product are measuring different things.
A declared unit (“1 kg of product”) and a functional unit (“the quantity of product needed to deliver a defined service”) are not interchangeable. A coating compared per kilogram looks worse than a thinner coating that delivers the same protection over twice the area; compared per square metre of protected surface, the ranking can reverse. ISO 14067 comparative assertions must be made on a functional unit that captures the service delivered, not a mass unit of convenience. Comparing per-kilogram footprints across products that deliver different functions is the most common invalid PCF comparison.
Product Category Rules close this gap within a category. A PCR — published under ISO 14025 / EN 15804 for that product type — fixes the functional unit, the boundary, the allocation method and the cut-off rules so that every declaration in the category is built the same way. Where a relevant PCR exists, ISO 14067 and the GHG Protocol Product Standard both expect it to be followed; a comparison between two declarations under the same PCR is valid, a comparison across PCRs or against an ad-hoc study is not.
Verification and Critical Review
ISO 14067 distinguishes between PCFs intended for internal use, for general business-to-business or business-to-consumer communication, and for public comparative assertions — and the verification bar rises with each.
- Internal / screening studies may be unverified, provided their limitations and data-quality reliance are documented. They inform decisions, not public claims.
- Communicated PCFs (an EPD, a Pathfinder-exchanged figure, a label) require verification proportionate to the claim. Type III declarations under ISO 14025 / EN 15804 require independent third-party verification of the PCF and the underlying LCA against the governing PCR.
- Comparative assertions disclosed to the public — a claim that product A has a lower footprint than product B — trigger the most stringent requirement: a critical review by a panel of interested parties under ISO 14044. This is the single hardest verification threshold in product carbon accounting, and it is the reason most organisations avoid public comparative claims unless the panel review is planned from the outset.
Verification examines the same things every time: that the boundary matches the declared scope, that cut-off was applied consistently, that allocation followed the ISO 14044 hierarchy with the chosen step justified, that biogenic and fossil carbon are reported separately, that the GWP basis is consistent and current, and that primary data was used where the standard expects it. A PCF that cannot evidence each of these is not verifiable regardless of how the headline number looks.
Error Traps with Calculable Magnitudes
Each error below produces a specific, quantifiable distortion. Magnitudes are shown against the worked example’s 5.31 kg CO2e/bracket cradle-to-gate result where the error is arithmetically traceable.
| Error | What happens | Magnitude | How to avoid |
|---|---|---|---|
| Cut off on mass alone | A low-mass but carbon-intensive input (a process gas, a coating) is excluded because it falls under a mass threshold. | Coating is 2.7% of input mass but 5.8% of the footprint — excluding it understates A1–A3 by ~0.31 kg (−5.8%). | Apply the environmental-significance test alongside mass and energy cut-offs. Never exclude on mass alone. |
| Net biogenic into the fossil total | Biogenic uptake (−1) is silently subtracted from the fossil CO2e figure to lower the headline number. | Reporting non-compliance under ISO 14067 §6 — biogenic and fossil must be separate lines, regardless of magnitude. | Report fossil CO2e and biogenic CO2e as distinct lines. Let the reader see the balance. |
| Mix AR5 and AR6 GWP | A database factor on an AR5 basis is summed with foreground gases characterised at AR6 without disclosure. | For methane-heavy inventories: AR5 CH4 = 28 vs AR6 = 29.8 → ~6% understatement on the CH4 contribution. | Characterise every gas on one basis (AR6). Disclose any AR5-internal database factor per line item. |
| Compare per-kg across different functions | Two products delivering different services are ranked on a mass unit rather than a functional unit. | Ranking can fully reverse — a thinner higher-intensity coating can win per m² of protection while losing per kg. | Define a functional unit that captures the delivered service before any comparative assertion. |
| Pick allocation out of order | Economic allocation is chosen for convenience when sub-division or a physical relationship was feasible. | Co-product split can swing 2–3× between mass and economic allocation when product values diverge from masses. | Work the ISO 14044 hierarchy top-down; document why each higher step was infeasible before descending. |
| Treat a screening study as a verified PCF | A spend-based or database-only screening number is communicated externally as if it were primary-data-backed. | Spend-based factors carry PCAF Score 4/5 uncertainty — order-of-magnitude error is possible on a single line. | Reserve external communication for studies meeting the data-quality and verification bar for the claim level. |
| Include capital goods inconsistently | Factory and machinery emissions are counted in one study and excluded in another, breaking comparability. | Per-unit capital-goods burden is usually immaterial but its inconsistent inclusion invalidates cross-study comparison. | Follow the governing PCR’s capital-goods rule. Declare the exclusion explicitly. |
Methodology Metadata — for PCF Documentation
Copy into the methodology statement of your PCF study or EPD background report for ISO 14067 / ISO 14025 transparency. Adjust the allocation and data-quality lines to match the study as executed.
| Methodology | GreenCalculus Cradle-to-Gate PCF Methodology v1.3 (June 2026). greencalculus.com/methodology/iso-14067-cradle-to-gate-methodology/ |
| Quantification standard | ISO 14067:2018, applying ISO 14040 / ISO 14044 for the underlying LCA. GHG Protocol Product Standard convergent where declared. |
| System boundary | Cradle-to-gate (modules A1–A3 per the EN 15804 modular convention). Partial PCF; A4 onward excluded. Capital goods excluded. |
| Functional / declared unit | [State the declared unit and, for any comparative assertion, the functional unit capturing the service delivered.] |
| Allocation | ISO 14044 §4.3.4 hierarchy: avoid → physical relationship → economic. [State the step applied and the justification for descending past higher steps.] |
| GWP basis | IPCC AR6 GWP-100, applied consistently. Fossil CH4 = 29.8, biogenic CH4 = 27.9, N2O = 273. Any AR5-internal database factors disclosed per line item. |
| Biogenic carbon | Reported separately from fossil. Uptake at 44/12 (3.667) kg CO2 per kg biogenic carbon; dLUC amortised over 20 years at 5% p.a.; storage credited only where permanent over 100 years. |
| Data quality | Primary site data for A3; supplier-specific PCF (Pathfinder) for material A1 flows where available, representative LCI database otherwise. Secondary-data reliance disclosed. |
| Cut-off criteria | [State mass / energy / environmental-significance thresholds and what was excluded.] |
| Verification | [Internal / third-party verified to ISO 14025 / critical-review panel per ISO 14044 — match to the claim level.] |
PCF methodology series. Core methods: cradle-to-gate, cradle-to-grave, allocation, frameworks comparison, sensitivity & hotspots. Sector methods: food, apparel & textile, electronics, packaging, beverages.
Frequently Asked Questions
Cradle-to-gate covers raw-material extraction (A1), inbound transport (A2) and manufacturing (A3) — it stops when the product leaves the factory. Cradle-to-grave extends that to distribution (A4), installation (A5), the use stage (B) and end-of-life (C), capturing the full life cycle. Cradle-to-gate is the dominant boundary for business-to-business accounting because a manufacturer can measure everything up to its own gate but not how the product is used or disposed of downstream. The receiving organisation then treats the cradle-to-gate figure as the emission factor for the purchased good in its Scope 3 Category 1 inventory.
They quantify the same thing under different governance and are broadly convergent — both require the four LCA phases, both use IPCC GWP-100, both demand separate biogenic and fossil reporting and the land-use-change rules. The differences are in emphasis: ISO 14067 is more prescriptive on comparability and critical-review conditions, while the GHG Protocol Product Standard places heavier weight on inventory uncertainty assessment. A single study can usually be designed to satisfy both. Declare which standard governs and follow its specific rules where they diverge.
Biogenic carbon is tracked separately from fossil carbon. Uptake during biomass growth is recorded as a negative emission (−44/12, or 3.667, kg CO2 per kg biogenic carbon) and release on combustion or decomposition as a positive emission. Where all biogenic carbon taken up is released within the boundary, the two cancel. The exception is biogenic methane, which leaves the boundary at a GWP-100 of 27.9 (AR6) — more potent than the CO2 taken up — so the balance does not close and a real positive contribution remains. Biogenic and fossil CO2e are always reported as separate lines, never netted into one figure.
Only if both were built the same way. Comparability under ISO 14067 requires the same functional unit, the same system boundary, the same cut-off criteria, the same allocation approach, equivalent data quality and — where one exists — the same Product Category Rule. Two numbers that are both cradle-to-gate and both in kg CO2e are not automatically comparable; they may be measuring different functions on different boundaries. Public comparative assertions additionally trigger a critical-review panel under ISO 14044, which is the most stringent verification requirement in product carbon accounting.
A1 is raw-material supply: the extraction and processing of every input material, including purchased intermediates and recycled feedstock. A2 is the inbound transport of those materials from supplier to factory. A3 is manufacturing: all on-site production, purchased electricity and heat, on-site fuels, direct process emissions and the primary packaging applied at the gate. Capital goods (the building and machinery) are generally excluded by convention, and that exclusion must be declared. Distribution packaging and outbound transport belong to A4 and are outside the cradle-to-gate boundary.
It depends on the claim. Internal and screening studies may be unverified provided their limitations are documented. A PCF communicated externally — as an Environmental Product Declaration, a Pathfinder-exchanged figure, or a label — requires verification proportionate to the claim, and an EPD under ISO 14025 / EN 15804 requires independent third-party verification against the governing Product Category Rule. A public comparative assertion that one product is lower than another triggers the highest bar: a critical review by an interested-party panel under ISO 14044.
Spend-based environmentally-extended input-output factors (kg CO2e per unit of spend) are the lowest data-quality tier and should be used only for screening, or as a last-resort fallback for a background flow where no supplier PCF and no representative LCI database factor exists. They carry PCAF Score 4/5 uncertainty, where order-of-magnitude error on a single line is possible. They are legitimate for a first-pass study provided the reliance is disclosed and a plan exists to replace material flows with supplier-specific primary data. See the spend-based methodology for the calculation detail.