ISO Alignment: How Greentruth's QETs Map to ISO 14064-3 and ISO 14067

For auditors, verifiers, and technical ESG readers, ISO alignment is the question that decides whether a fuel- or electricity-attribute certificate is ready for an assurance review or just looks like it should be. Greentruth's Quantified Emissions Tokens (QETs) align to two normative references — ISO 14064-3 for verification and ISO 14067 for product carbon footprint — with specific clauses of each standard mapped to the underlying methodology. This page lays out which clauses matter, what the verifier sees, and what the standards actually require.

ISO alignment for QETs, in one paragraph. Greentruth's QETs are verified to ISO 14064-3 reasonable assurance at the token level, with methodology alignment to ISO 14067 for product carbon footprint reporting. The two are the only standards cited as normative references in the QET-NG methodology v2.3 and the QET-RNG methodology v2.1.2. ISO 14064-1 (organizational GHG inventories) and ISO 14064-2 (project-level GHG accounting) are adjacent references — relevant to corporate-level reporting that consumes QETs, not directly normative to the QET methodology itself.

For the foundational QET overview

The ISO landscape includes a dozen standards relevant to corporate sustainability accounting, and reporters frequently encounter the 14060 family without a clear sense of which standards apply where. For QETs specifically, the answer is concrete: two standards are cited as normative references in the methodology, and they do two different things.

• ISO 14064-3. The verification standard. Defines requirements for the validation and verification of GHG statements — the principles, the level of assurance, the verification plan, evidence sampling, materiality thresholds, the verification statement itself. Every QET issued on the EarnDLT registry carries a reasonable-assurance verification under this standard from an accredited third party, stamped on the certificate at issuance.
• ISO 14067. The product carbon footprint standard. Defines requirements for quantifying and reporting the carbon footprint of a product using lifecycle-based methodology — goal and scope definition, functional unit, system boundaries, data quality, uncertainty, and reporting transparency. The QET methodology aligns to these requirements at the structural level: the "product" being footprinted is the defined physical unit each token represents — one MMBtu of natural gas, one MMBtu of RNG thermal energy, and so on.

Together, the two standards define what gets reported (14067) and how it gets verified (14064-3). Each QET carries evidence of both.

For the QET-NG methodology in detail

For the QET-RNG methodology

The 14064-3:2019 standard — Greenhouse gases — Part 3: Specification with guidance for the verification and validation of greenhouse gas statements — is what auditors and verifiers operate under when reviewing a GHG statement. The standard sets out:

• Principles governing the conduct of the verification (Clauses 4.1–4.3).
• Levels of assurance (limited vs reasonable) and verification objectives (Clauses 5.2–5.3).
• The verification plan (Clause 7.2).
• Assessment of GHG information, internal controls, and data sampling (Clauses 7.3–7.4).
• Evaluation of misstatements and uncertainty against materiality thresholds (Clauses 7.6–7.7).
• Evaluation of the GHG statement (Clause 7.9).
• Quality management and record-keeping (Clauses 8.2–8.3).
• The verification report itself (Clause 9.1).

The practical question for an auditor reviewing a QET-backed disclosure is whether the token records the inputs the standard expects to be reviewable: verifier-of-record identity, evidence sample sizes, materiality thresholds, uncertainty quantification, and the verification opinion itself. Greentruth's QET methodology is structured so each of these is recorded as a token attribute at issuance, not produced separately at disclosure time.

The 14067:2018 standard — Greenhouse gases — Carbon footprint of products — Requirements and guidelines for quantification — defines how to calculate and report a product carbon footprint. For QETs, the relevant clauses are:

• Goal and scope definition, functional unit, system boundaries (Clauses 6.1–6.3). The QET methodology defines the functional unit precisely: 1 MMBtu of natural gas (QET-NG), 1 MMBtu of RNG thermal energy (QET-RNG), 1 MWh of electricity (QET-ELEC), or 1 tonne of geologically stored CO₂ (QET-CCS). System boundaries are also explicit: well-to-pipeline-injection for QET-NG / QET-RNG, with end-use combustion out of scope.
• Data quality and uncertainty (Clauses 7.4–7.5). The QET methodology's four-tier data hierarchy (site-specific primary → industry-average secondary) maps directly to the standard's data quality requirements, with each tier's uncertainty profile documented.
• Reporting of product carbon footprint results (Clause 8). The QET's machine-readable JSON output and human-readable PDF together satisfy the transparency requirements of the reporting clause.

How the data-quality hierarchy works

For verifiers and technical readers, here is the concrete clause-level mapping the QET-NG methodology and QET-RNG methodology document explicitly:

The mapping is what lets an accredited verifier reconstruct the calculation against the standards as written, rather than against a Greentruth-specific schema. Clause-level alignment, recorded at issuance, survives a verifier review better than a Greentruth-internal cross-walk.

How retirement records preserve methodology version

Three operational details from the 14064-3 workflow are worth pulling out because they show up on virtually every audit cycle:

• Sampling. The standard requires verification on explicit portions of the portfolio. The QET methodology applies sampling at 5% at the batch level and 2% for portfolios — practical guardrails that scale across thousands of tokens without dropping below the standard's expectation of evidentiary rigor.
• Unit verification. The verifier confirms the carbon intensity unit (kgCO₂e/MMBtu for QET-NG and QET-RNG; analogous units for QET-ELEC and QET-CCS) with all conversions documented and cross-checked. Mismatched units are one of the most common verifier-side flags.
• Materiality and opinion form. The standard distinguishes limited assurance (negative-form opinion: "nothing has come to our attention...") from reasonable assurance (positive-form opinion). Every Greentruth QET carries reasonable-assurance verification — the higher bar — so the verifier-side standard the audit reconstructs against is the harder one.

The verifier on the other side of a buyer's disclosure does not have to construct the audit trail from disparate evidence. Each QET carries the inputs the standard asks the verifier to evaluate.

How limited vs reasonable assurance differs in practice

For the GHG Protocol overlay

Two related standards in the 14060 family come up frequently in adjacent reporting work, even though they are not normative references in the QET methodology itself:

• ISO 14064-1:2018 — Specification with guidance at the organization level for quantification and reporting of greenhouse gas emissions and removals. This is the standard corporate inventories are commonly aligned to. QETs feed corporate-level reporting under 14064-1 when the buyer's organizational inventory consumes QET-anchored data for specific scope lines, but the standard does not govern the issuance of the token itself.
• ISO 14064-2:2019 — Specification with guidance at the project level for quantification, monitoring and reporting of greenhouse gas emission reductions or removal enhancements. This is the standard project-level GHG accounting follows (for example, in offset programs). It does not govern QETs, which are fuel- or electricity-attribute certificates rather than project-level reduction or removal claims.

The distinction matters: a verifier asking which standard applies should know that 14064-3 + 14067 are the normative references for the QET itself, while 14064-1 is relevant to the corporate inventory that consumes QET data and 14064-2 is relevant to a different class of instrument entirely.

How QETs align across reporting frameworks

ISO 14064-3 standard page

ISO 14067 standard page

Clauses 8.2–8.3 require quality management and record-keeping for the verification — and the underlying records and chain-of-custody need to be retained for a defined period to support potential re-verification.

Greentruth's implementation:

• Records and chain-of-custody retained for at least 10 years per QET, exceeding the typical retention expectation.
• Cryptographically secured documentation through the EarnDLT registry on Hedera Hashgraph — tamper-evident timestamping, immutable mint and retirement records.
• Methodology and reference dataset version pinned at issuance — when guidance evolves (CNZS V2.0, GHG Protocol updates, CARB rulemaking), the QET retains its original version reference, so audit work years later reconstructs against the version in force at the time of issuance.

This is the structural difference between "we have a policy to retain records" and "the records are part of the registry record."

How regulatory pathways consume ISO-verified records

For SB 253 reporters specifically

For LCFS submissions