Sustainability Claims Evidence Requirements: What Proof Do You Need Under EU Law?

"Show your evidence" — that's the core message of every EU green claims regulation adopted since 2024. But what evidence, exactly? A company making different types of environmental claims needs different types of proof, and the bar varies depending on the claim's specificity, scope, and audience.

After reviewing dozens of enforcement cases and regulatory guidance documents, I've mapped the evidence requirements by claim type. This isn't legal advice — it's a practical framework for understanding what regulators expect.

The Evidence Hierarchy

Not all evidence is created equal. Regulators implicitly apply a hierarchy when assessing substantiation:

1. Third-party verified data — Externally assured measurements, independently certified results. Gold standard.
2. Standardised methodology results — LCA per ISO 14040/14044, PEF per EU methodology, GHG inventory per ISO 14064. High credibility.
3. Internal measurements with documented methodology — Self-reported data with transparent methodology and raw data available for inspection. Acceptable for many claims.
4. Industry averages or benchmarks — Useful for comparative context but insufficient as sole evidence for product-specific claims.
5. Supplier declarations — Certificates from suppliers about material composition, sourcing, etc. Acceptable if verifiable, but transfer of liability is limited.
6. Qualitative assessments — Expert opinions, general research references. Weakest evidence category, rarely sufficient alone.

Evidence by Claim Type

Carbon Footprint Claims

Claim example: "This product has a carbon footprint of 2.3 kg CO₂e per unit."

Required evidence:

• Life Cycle Assessment per ISO 14040/14044 or Product Environmental Footprint (PEF) study per EU methodology
• System boundaries clearly defined — which lifecycle stages are included and excluded
• Data quality requirements met — primary data for significant processes, secondary data from recognised databases (ecoinvent, GaBi) for background processes
• Third-party critical review per ISO 14071 recommended for consumer-facing claims
• Date of assessment — regulators expect evidence less than 3-5 years old depending on industry

The Product Environmental Footprint Category Rules (PEFCRs) — available for sectors including dairy, beer, pet food, batteries, and T-shirts — provide additional specificity. Where a PEFCR exists for your product category, using it strengthens substantiation significantly.

Recycled Content Claims

Claim example: "Made from 85% post-consumer recycled plastic."

Required evidence:

• Chain of custody documentation from material supplier through to final product
• Certification under a recognised scheme: RecyClass, ISCC PLUS, EuCertPlast, or equivalent
• Distinction between post-consumer and post-industrial recycled content (consumers perceive these differently)
• Mass balance methodology disclosure if applicable
• Annual verification — recycled content can vary by production batch

Recyclability Claims

Claim example: "100% recyclable packaging."

Required evidence:

• RecyClass or equivalent design-for-recycling assessment
• Evidence that recycling infrastructure exists and is accessible to the consumer — a technically recyclable material means nothing if no collection system exists in the target market
• Specification of conditions: is this recyclable in all EU markets or only specific ones?
• Contamination assessment — does the packaging design (multi-material, adhesives, inks) prevent effective recycling in practice?

This is one of the areas where the gap between technical truth and consumer understanding is largest. A PET bottle is "100% recyclable" in theory, but if it has a full-body shrink-wrap label, the recycling rate drops dramatically because sorting facilities can't identify the material.

Biodegradability and Compostability Claims

Claim example: "Compostable packaging."

Required evidence:

• Certification to EN 13432 (industrial composting) or OK Compost Home (home composting)
• Clear specification of conditions — "compostable" without qualification implies home compostability, which requires different certification than industrial
• Evidence of composting infrastructure availability in target markets
• Timeframe disclosure — "compostable in 12 weeks under industrial conditions" is specific; "compostable" alone is not

"Natural" and "Organic" Claims

Claim example: "Made with natural ingredients."

Required evidence:

• For food: EU Organic Regulation (2018/848) certification if using "organic." "Natural" has no harmonised EU definition for food — making it a compliance risk
• For cosmetics: ISO 16128 defines natural and organic content percentages. COSMOS or NATRUE certification provides third-party verification
• For textiles: GOTS certification for organic fibres; no EU-harmonised definition for "natural" textiles
• The word "natural" alone, without specification of what percentage of ingredients are natural and by what definition, is considered a generic claim under the ECGT

Emissions Reduction Claims

Claim example: "We reduced our carbon emissions by 30% since 2020."

Required evidence:

• Baseline year emissions data (Scope specification: 1, 2, 3, or all)
• Current year emissions data using the same methodology
• Methodology disclosure — are these absolute reductions or intensity-based?
• Explanation of any structural changes (acquisitions, divestitures) that affect the comparison
• Preferably: GHG inventory per ISO 14064 or GHG Protocol, with third-party verification

Comparative Claims

Claim example: "30% less CO₂ than the category average."

Required evidence:

• Methodology for determining the category average — what products are included, what data source
• Same system boundaries for both the product and the benchmark
• Date relevance — the comparison must use contemporary data
• The comparison must be fair — comparing a new product to outdated competitor data is misleading
• Disclosure must be specific enough for a consumer to verify independently

The PEF Framework

The EU's Product Environmental Footprint (PEF) methodology deserves special attention because the Green Claims Directive is expected to make it the default methodology for product-level environmental claims.

PEF covers 16 impact categories — not just carbon. These include acidification, eutrophication, water use, resource depletion, ecotoxicity, and more. A PEF study provides the most comprehensive evidence base for product environmental claims.

PEF Category Rules (PEFCRs) exist for specific product categories and define exactly how to conduct the assessment: which lifecycle stages to include, what data quality is required, how to handle allocation, and what functional unit to use.

Conducting a full PEF study is expensive — typically €15,000-50,000 depending on product complexity and data availability. But for companies making significant consumer-facing environmental claims about specific products, it may become necessary.

Building Your Evidence File

For each environmental claim your company makes, maintain an evidence file containing:

1. The claim — exact wording as used in marketing
2. Evidence type — which tier of the evidence hierarchy
3. Supporting documents — LCA reports, certifications, test results, supplier declarations
4. Methodology disclosure — how the evidence was generated
5. Date and validity — when the evidence was produced and when it needs updating
6. Responsible person — who approved the claim-evidence pairing
7. Scope and limitations — what the evidence covers and doesn't cover

This evidence file is what regulators will request during an investigation. Having it ready demonstrates good faith and may mitigate penalties even if a compliance gap is found.

Start by scanning your website with our Green Claims Scanner to identify all claims that need evidence documentation.

Related: Compliance Checklist | PEF Methodology Guide | EU-Approved Certifications