Does the Greenhouse Gas Protocol Product Standard require assurance of a product footprint, and is verification the only route?

The Greenhouse Gas (GHG) Protocol Product Standard says the product inventory shall be assured by a first or third party. Assurance can be verification, at limited or reasonable level, or critical review, where a review panel should have at least three members.

What the standard requires

• The product GHG inventory shall be assured by a first or third party.
• Companies shall choose assurance providers independent of, and with no conflicts of interest with, the inventory process.
• Companies shall report the assurance statement in the inventory report.
• The statement shall include: the level of assurance, limited or reasonable, with the opinion or the critical review findings; whether it was first or third party; a summary of the process; the assurers' relevant competencies; and, for first party assurance, how conflicts of interest were avoided.

Two routes to assurance

• Verification: an independent assessment of the reliability of the inventory, at limited or reasonable level. The standard says absolute assurance is never provided, because not all inputs can be tested.
• Critical review: a check that methods follow the Product Standard and are scientifically and technically valid, that data are appropriate and reasonable for public reporting, and that the report and conclusions are transparent, consistent and suitable for a GHG-only inventory.
• A critical review is done by an internal or external expert, or by a panel of interested parties. For a panel, the standard says it should have at least three members, who may come from life cycle assessment expert groups, government agencies, non-governmental organisations, industry groups and other companies.

First party or third party

First party means the reporting company's own people, independent of the inventory work. Third party means another organisation. The standard says third party assurance is likely to raise credibility with outsiders, while first party assurance can still add confidence and be a useful rehearsal before commissioning a third party.

What makes an assurer competent

The standard asks for experience with assurance frameworks, knowledge of life cycle assessment or corporate GHG accounting, knowledge of the company's activities and sector, the ability to judge sources and the size of possible errors, and credibility, independence and professional scepticism.

What Senseible does here

Senseible reads fuel invoices and electricity bills into monthly records, which supply the fuel and power evidence behind a product footprint. Senseible is not an assurer and does not carry out verification or critical review.

• How Senseible checks records
• Does an LCA need a critical review
• How to disclose a product carbon footprint
• What goes in an International Organization for Standardization (ISO) 14067 report

Sources: GHG Protocol Product Life Cycle Accounting and Reporting Standard, chapter 12 Assurance

Last reviewed 2026-11-04. Wording is from the 2011 Product Standard. A buyer may add its own rules on top, so ask which standard and which assurance route it expects.