# What should a carbon footprint claim on a product or website disclose so buyers trust it?

Canonical: https://senseible.earth/answers/how-to-disclose-a-product-carbon-footprint

State the number with its unit and what it covers: kg CO2e per declared unit, the life cycle stages included, the standard followed, the year of data, the GWP set, what was excluded and whether it was independently reviewed. A bare figure with no boundary cannot be compared or checked, so a careful buyer will discount it.

## The minimum to disclose next to the number

- Value and unit, for example kg CO2e per kg of product, per piece or per square metre.
- Boundary: cradle to gate, cradle to grave, or gate to gate.
- Standard: ISO 14067:2018 or the GHG Protocol Product Standard.
- Reference period: which year's production and energy data.
- GWP set and time horizon, for example IPCC AR6, 100 years.
- Share of primary data from your own sites versus database values.
- Exclusions and cut-off rules, named.
- Review status: critical review, third-party verification, or self-declared.

## Items ISO 14067 says to report separately

- Offsets and carbon credits: not part of the footprint; show them separately if at all.
- Biogenic carbon: report emissions and removals from plant-based materials separately.
- Electricity: state how purchased power was treated, especially if you claim renewable supply.

## Wording that loses trust

- "Low carbon" or "green" with no figure or comparison base.
- "Carbon neutral product" when the claim rests on offsets; EU consumer law (Directive (EU) 2024/825) restricts this.
- A comparison with a competitor's product that used a different boundary or standard.
- A figure for one plant shown as if it covered all plants or all product grades.

## Where to put the detail

On a product page or label, give the value, unit, boundary and standard in one line, and link to a short methodology note with the rest. ISO 14026 sets principles for this kind of footprint communication: the information must be relevant, transparent and not misleading, and the supporting report must be available on request.

## Example of a disclosure line

- "2.4 kg CO2e per kg of grey cotton yarn, cradle to gate, ISO 14067:2018, FY 2025-26 data from our Coimbatore mill, GWP100 IPCC AR6."
- "62% primary data. Excludes capital goods and packaging. Self-declared; not third-party verified."
- "Methodology note available on request."

Illustrative wording with a made-up value; use your own study's figures.

## What Senseible does here

Senseible's product footprint calculator and records keep the factor and source behind every line, which supports a transparent methodology note. It does not review or verify a footprint claim, and it is not a substitute for an ISO 14067 study where a buyer asks for one.

- [Product carbon footprint calculator](https://senseible.earth/calculators/product-carbon-footprint)
- [Greenwashing self-audit checklist](https://senseible.earth/climate-intelligence/msme-greenwashing-self-audit-checklist-2026)
- [What goes in an ISO 14067 report](https://senseible.earth/answers/what-goes-in-an-iso-14067-report)

Sources: [ISO 14067:2018, Carbon footprint of products](https://www.iso.org), [ISO 14026:2017, Communication of footprint information](https://www.iso.org), [GHG Protocol Product Life Cycle Accounting and Reporting Standard (2011)](https://ghgprotocol.org/standards)

Last reviewed 2026-10-15.