ISO 14067: Carbon Footprint of Products

Please note: This article is for educational purposes only. It does not replace the ISO and EN standards. If you work at a university, you probably already have a licence to view the complete standards. If not, please go to your relevant national provider of standards.

ISO 14067:2018 defines how to calculate product carbon footprints (CFPs). Companies use it to quantify GHG emissions across life cycles, from resource extraction through manufacture, use, and disposal. The standard comes from the ISO 14060 family of GHG standards. Published September 2018, it replaced ISO/TS 14067:2013 and narrowed its scope significantly.

What ISO 14067 Actually Is#

ISO 14067 is a subset of life cycle assessment that looks only at climate change. Full LCA under ISO 14044 examines multiple environmental impacts: acidification, eutrophication, resource depletion, water use, toxicity. Carbon footprinting strips that down to a single metric: kilograms of CO₂ equivalent.

This creates a problem. You can optimise for carbon whilst making other environmental impacts worse. ISO 14067 explicitly states it addresses only a single impact category — climate change — and does not assess any social or economic aspects or impacts, or any other environmental aspects. See how carbon footprint differs from full LCA for the broader picture.

The Verification Gap#

Here’s where ISO 14067 differs fundamentally from Environmental Product Declarations.

EPDs require mandatory third-party verification:

• Independent verifier checks all calculations
• Site visits to validate primary data
• Multiple rounds of corrections (typically 2-3)
• Verification takes 5-20 weeks
• Verifier must be accredited
• Results published in public registry

ISO 14067 makes verification optional: Clause 8 states “a critical review facilitates understanding and enhances the credibility of CFP,” then adds “if any” review shall follow ISO/TS 14071. There is no requirement for site visits, no mandatory external checking, no public registration. You can calculate a CFP, report it internally or externally, and never have anyone verify your numbers.

Without mandatory verification, two things happen: companies can make calculation errors (allocation mistakes, boundary omissions, data gaps) that never get caught, and companies can make methodological choices that favour their products without independent scrutiny.

ISO 14044 (full LCA standard) requires panel review for comparative assertions disclosed to the public. ISO 14067 mentions this requirement exists but doesn’t enforce it.

CFP vs EPD: Critical Differences#

Aspect	Carbon Footprint (ISO 14067)	EPD (ISO 14025 + EN 15804)
Scope	Climate change only	15+ impact categories
Verification	Optional	Mandatory third-party
Product Category Rules	Optional (via ISO/TS 14027)	Mandatory
Public disclosure	Not required	Required (registered database)
Site visits	Not required	Typically required
Validity period	None specified	5 years maximum
Timeline	2-3 months possible	5-8 months typical
Cost	Lower (no verification)	Higher (£5,000-15,000+)
Comparability	Poor (different methodologies)	Better (PCR standardisation)
Credibility	Depends on voluntary review	Built-in through verification

EPDs use Product Category Rules (PCRs) that specify exact methodologies for product types. All concrete EPDs follow the same PCR, all window EPDs follow another PCR. This enables meaningful comparison within categories. ISO 14067 allows PCR use through ISO/TS 14027 but doesn’t require it. Without PCRs, every CFP study can use different system boundaries, allocation methods, data sources, and assumptions. Results become incomparable.

CFP vs Full LCA#

Full LCA under ISO 14044 examines products across multiple dimensions including climate change, acidification, eutrophication, ozone depletion, photochemical ozone creation, resource depletion, water use, land use, ecotoxicity, human toxicity, and particulate matter formation.

ISO 14067 strips all that away. You get carbon numbers but miss everything else. A biofuel might have low carbon emissions but destroy peatland ecosystems. Recycled aluminium has lower carbon than virgin but the recycling process might generate significant water pollution. ISO 14067 won’t tell you about these trade-offs. For comprehensive environmental assessment, you need full LCA.

Core Methodology#

System Boundaries#

Every CFP study draws a boundary around what gets counted. Cradle-to-gate: raw materials through factory gate (common for business-to-business products). Cradle-to-grave: full life cycle including consumer use and disposal. Cradle-to-cradle: includes recycling and recovery back into production. Gate-to-gate: just one stage (manufacturing only, excluding upstream materials).

ISO 14067 requires life-cycle-wide boundaries for complete CFPs. Partial CFPs can use narrower boundaries but must disclose excluded stages. Without verification, boundary choices go unchallenged.

Functional Unit#

Instead of “per product”, CFPs use functional units that define service provided. Examples: not “one light bulb” but “10,000 hours of illumination”; not “one car” but “100,000 km of passenger transport”; not “one paint tin” but “coverage of 50 m² to specified durability.” The functional unit choice affects results dramatically.

Methodological Foundation#

Data Quality#

ISO 14067 lists data quality requirements — time coverage, geographical coverage, technology coverage, precision, completeness, representativeness, consistency, reproducibility — but doesn’t specify minimum thresholds. EPD verifiers check data quality against PCR requirements. CFP studies without verification rely on self-reporting.

Primary data (measured from actual operations) is most reliable. Secondary data (from databases like ecoinvent) provides generic averages. Proxy data (estimates from similar processes) is least reliable. ISO 14067 requires documenting data sources but doesn’t mandate minimum primary data percentages. EPD PCRs often require 75%+ primary data for foreground processes.

Allocation#

When industrial processes produce multiple products simultaneously, how do you split environmental burdens? ISO 14067 follows ISO 14044’s allocation hierarchy: first avoid allocation by subdividing processes (often impossible), then use physical allocation based on mass, energy, or other physical property, and finally use economic allocation based on revenue or market value as a last resort.

Different allocation methods produce different results. Both methods comply with ISO 14067. Neither is objectively “correct.” Without verification, allocation choices go unchallenged.

Biogenic Carbon#

ISO 14067 requires separate reporting of biogenic uptake (CO₂ absorbed during plant growth), biogenic emissions (CO₂ released during use/decay), and fossil emissions (from processing biogenic materials). The standard allows various approaches to land-use change emissions, and permits multiple methods, each giving different answers.

Electricity Treatment#

ISO 14067 permits several approaches: consumption mix (average grid emissions where electricity gets used), supplier-specific (emissions from your actual electricity supplier), and contractual instruments (Renewable Energy Guarantees of Origin, Power Purchase Agreements). Each produces different numbers. This matters enormously for electric vehicles and other energy-intensive products.

Recycling and Circularity#

ISO 14067’s Annex D describes several approaches to recycling. The cut-off method: recycled material enters the system burden-free; original product gets no credit for recyclability; the next product benefits from using recycled content. Avoided burden: original product gets credited for recycling potential. Closed-loop: for stable recycling systems, assume perfect loop.

Same physical reality, opposite accounting results — both valid under ISO 14067. EPD PCRs specify which method to use within product categories. ISO 14067 without PCRs lets each study choose, making comparison meaningless.

Impact Assessment#

ISO 14067 doesn’t mandate which IPCC assessment report to use. Fifth Assessment Report (AR5) uses GWP over 100 years. Sixth Assessment (AR6) revised factors based on updated science. The standard also permits shorter or longer time horizons (20-year, 500-year GWPs). These choices are policy decisions disguised as technical details that fundamentally alter which products appear preferable.

What ISO 14067 Explicitly Excludes#

The standard doesn’t cover: carbon offsetting (purchasing credits to compensate emissions), communication (how to report or market CFP results — see ISO 14026), social impacts, economic impacts, or any other environmental impacts beyond climate change. It excludes carbon offsetting from calculations — you can’t subtract purchased carbon credits from your CFP.

The Comparability Problem#

ISO 14067’s Annex A states: “Because of these limitations, the results of a quantification of the CFP in accordance with this document are often not a sound basis for comparisons.” Comparisons are only valid when studies use identical product category rules, equivalent functional units, equivalent system boundaries, equivalent data quality, equivalent allocation procedures, equivalent impact assessment methods, and equivalent assumptions. In practice, independent CFP studies rarely meet all these criteria.

The Reality of CFP Use#

ISO 14067 serves several legitimate purposes: internal decision-making (comparing design alternatives within one organisation), hotspot identification (finding high-emission stages in your supply chain), trend monitoring (tracking your own products over time), regulatory compliance (where regulations reference ISO 14067 specifically), and supplier engagement.

What ISO 14067 doesn’t support well: marketing claims (without verification, claims lack credibility), product comparison (different methodologies make comparison meaningless), financial instruments (carbon pricing, taxes, or trading schemes need verified data), and regulatory enforcement.

CFP vs EPD: When to Use Which#

Use CFP (ISO 14067) when: you need quick carbon screening (2-3 months), budget is limited, results stay internal for decision-making, you’re comparing your own design alternatives, a regulatory requirement specifically references ISO 14067, or you don’t need public credibility yet.

Use EPD (ISO 14025/EN 15804) when: you need public credibility and third-party verification, making comparative public claims, operating in the construction sector (often mandatory), need to demonstrate compliance rigorously, or results will appear in tenders or procurement.

Use full LCA (ISO 14044) when: you need to understand trade-offs between environmental impacts, carbon alone gives a misleading picture, or you’re designing products where multiple impacts matter.

Practical Implementation#

Phase 1: Define scope carefully. Be honest about boundaries — excluding difficult stages doesn’t make emissions disappear. Choose a functional unit that enables meaningful comparison. Document why you made each methodological choice.

Phase 2: Prioritise data quality. Use primary data where emissions concentrate. Database values are fine for minor contributors. Document data sources transparently and acknowledge where you used estimates.

Phase 3: Model systematically. Use proper LCA software (openLCA, SimaPro, GaBi). Check mass balances. Verify energy calculations against known benchmarks.

Phase 4: Interpret honestly. Uncertainty often exceeds ±20%. Identify hotspots (stages contributing >10% of total). Run sensitivity analysis on key assumptions.

Phase 5: Report transparently. Include all required elements per Clause 7. Explain limitations clearly. If using for comparison, verify Annex B compliance. Consider voluntary verification to build credibility.

Common Errors#

Boundary errors: Excluding significant life cycle stages (especially use-phase for energy-using products). Allocation errors: Using economic allocation when physical would be more appropriate, or vice versa. Double counting: Including both recycling credit at end-of-life AND using recycled content at beginning-of-life. Data mixing: Combining recent data with outdated emission factors. Comparability claims: Stating “lower carbon than X” without verifying methodological equivalence. False precision: Reporting 2.347 kg CO₂ when uncertainty is ±0.5 kg. Missing biogenic carbon: Failing to report biogenic flows separately as required.

Software and Databases#

Conducting credible CFPs requires LCA software such as openLCA (free, open-source), SimaPro, GaBi, or Umberto. Key life cycle databases include ecoinvent (most comprehensive, subscription), GaBi databases, ELCD (European Life Cycle Database, free), US LCI (US-focused, free), and Agribalyse (agricultural products, free). Database quality varies significantly — ecoinvent provides well-documented, peer-reviewed data.

Key Takeaways#

1. ISO 14067 defines carbon footprinting methodology but makes verification optional. This creates a credibility gap compared to EPDs.
2. CFPs measure only climate change. Full LCA examines 15+ environmental impacts. Carbon optimisation can worsen other impacts.
3. Methodological choices matter enormously. System boundaries, allocation, electricity treatment, recycling approaches all fundamentally shape results.
4. Comparability is problematic. Different CFP studies usually aren’t comparable unless using identical methods.
5. Use CFPs for internal decisions, EPDs for public claims. If you need third-party credibility, the optional verification of ISO 14067 isn’t sufficient.
6. The standard acknowledges its own limitations. Annex A explicitly states results “often” aren’t suitable for comparison.

ISO 14067 provides valuable methodology for carbon accounting. Used carefully with appropriate caveats, it supports better environmental decisions. The difference between good and bad CFPs comes down to intellectual honesty, methodological rigour, and transparent documentation. Without mandatory verification, those qualities depend entirely on the organisation conducting the study.