LCA critical review:
how to choose an independent expert

Many life cycle assessments (LCAs) are described as "reviewed". Yet ISO 14044, the standard that governs critical review, makes it mandatory in only 1 case, and outside that case the word covers very uneven practices.

RECYC-QUÉBEC is the Quebec government corporation responsible for waste reduction. Its published reviews, like those of ADEME (the French Agency for Ecological Transition) or of a brand such as Hamac, show what a genuine review looks like: a panel of 3 to 5 people, up to nearly 200 comments and 3 to 6 months of exchanges. The right level of review depends first on what the study will be used for, then on who reviews it.

1What is an LCA critical review?

A critical review is an independent examination of an LCA study, provided for in clause 6 of the ISO 14044 standard, which states whether an outside reader can rely on its conclusions. The reviewer does not redo the study. Depending on the contract, they read the report alone, as the ADEME panel did in 2023, or also rerun part of the model, as the RECYC-QUÉBEC panel did in 2014 in the SimaPro software.

What the standard asks of the reviewer

The standard sets the reviewer 5 objectives. The reviewer checks that the methods are consistent with the standard and scientifically valid, that the data are appropriate to the goal of the study, that the interpretations reflect its limitations, and that the report is transparent and consistent.

Expert reading, review, panel, verification: what is the difference?

Behind the word "review", quotes describe pieces of work that do not carry the same weight with a third party:

• An expert reading is entrusted to a specialist from outside the study, who reads the report and the model and then returns written comments, without following any particular standard.
• A critical review by an expert follows clause 6 of ISO 14044 and ends with a review report attached to the study, together with the commissioner's responses.
• A review by a panel is required for a published comparison: a chair and at least 2 other reviewers, with complementary expertise, examine the study together.
• The verification of an environmental product declaration (an FDES, the French format for construction products; an EPD elsewhere; a Product Environmental Profile (PEP) for electrical equipment) checks compliance with the rules of its programme and is carried out by an approved verifier.

The misunderstanding comes from everyday language: "we had the study reviewed" often means an expert reading, whereas a buyer who reads "ISO 14044" understands that a formal review has taken place.

What the review does not guarantee

The review does not issue a certificate: it produces a reasoned opinion and a report, attached to the study, without validating the goal of the study or the decision the commissioner draws from it. Nor does it inspect a site: the reviewer reads a report and a model, not energy bills, unlike the verification of a carbon footprint assessment. In the review of the comparative LCA of Hamac nappies, in 2013, one reviewer makes this explicit in their opinion: the method was reviewed, not the accuracy of the data. The checks to carry out yourself before the review are set out in our guide to verifying an LCA produced with software.

2When is an LCA critical review mandatory?

A comparison disclosed to the public

ISO 14044 requires a review by a panel of interested parties when the study supports a comparative assertion intended for the public, that is, a claim that a product performs better than, or as well as, a competing product that fulfils the same function. The panel has at least 3 members, including a chair chosen by the commissioner, and covers LCA, the product and sometimes the market. For a comparison that stays internal, is given to a named customer or is made against a market average, our guide to comparative LCA helps you choose between a single expert and a panel.

The standard adds a constraint that authors often discover late. A published comparison cannot rely on weighting of the indicators, which ISO 14044 does not regard as scientifically based, as a literature review published in 2016 points out. An advertisement saying "less polluting than" falls into this case, whether it compares an electric car with a combustion engine car or reusable packaging with single-use packaging. It is also the case most exposed to enforcement of environmental claims and to the audit that prepares for it.

An FDES, an EPD or a PEP

These declarations do not go through a critical review but through third-party verification. For construction products, it has been mandatory in France since 1 July 2017, according to the HQE-GBC association, and only the verifiers approved by each programme may carry it out. The details are in choosing an approved verifier, choosing between an FDES, an EPD and a PEP and the guide to the acronyms.

A request from a buyer, a label or a funder

Outside these 2 cases, no general rule requires an LCA to be reviewed. The EU Batteries Regulation provides for its own verification, and environmental labelling follows an official method. The proposed Green Claims Directive, which would have required prior verification of claims, was still awaiting the Council's position as of 16 October 2026, according to its procedure file. Proving a claim therefore rests on the file the company puts together itself.

The review then becomes a choice of evidence, often requested by a buyer, a label or a funder. The 2025 call for projects of the Métropole de Lyon, the Lyon metropolitan authority, funded the LCA and its critical review at 50%, up to a maximum of €10,000 in aid.

3How do you choose the expert who will review the study?

The choice comes down to 3 criteria, in this order: independence, competence, then way of working.

Independence, which is not negotiable

ISO 14044 requires the reviewer to be independent of the study: they neither carried out the calculation, nor chose its assumptions, nor have an interest in any particular result. The consultancy that carried out the LCA therefore cannot review it, any more than a colleague who approved the assumptions along the way. The standard accepts an internal reviewer who took no part in the study, but an external reviewer carries far more weight with a third party.

The competences set out in ISO 14071

ISO 14071:2024, published on 9 October 2024, supplements ISO 14044 on how the review is conducted and on reviewer competences, and replaces the 2014 technical specification. According to ISO, it applies to the critical review of any type of LCA study.

Of the competences it lists, 3 matter most:

• Command of LCA methodology and of ISO 14040 and 14044, to the point of spotting a poorly chosen scope or allocation rule on first reading.
• Knowledge of the sector, without which process and end-of-life assumptions cannot be judged: a medical device, a battery or a mattress.
• Familiarity with LCA databases and software, so as to find in the model what the report claims, beyond the PDF alone.

The questions to ask before the quote

5 questions are enough to sort the candidates during a first call, before any quote:

• Have you had any connection with the study, its author or its commissioner? The expected answer is a clear no; a "not really" rules the candidate out.
• Which LCAs in this sector have you carried out or reviewed? A reviewer who is new to the product misjudges the manufacturing, use and end-of-life assumptions.
• Will you review the model or only the report? A wrongly linked flow or a factor from another year shows up only in the software, not in the report.
• What will your review report contain? It must number the comments, keep the commissioner's responses and state what remains under reservation at the end.
• What would make you refuse to reach a favourable conclusion? A reviewer who cannot name any ground for refusal will not raise any reservation.

Conversely, 3 signals should give you pause:

• The quote promises to "validate" or "certify" the study, whereas the review delivers only a reasoned opinion and a report.
• The reviewer asks for neither the model nor the list of data, and offers to work from the PDF of the report alone.
• A panel is promised in 2 weeks, when the 2 published panel reviews cited here took 3 months and nearly 6 months.

4What does a review report contain?

The review report is what the commissioner is paying for. ISO 14044 provides for it to be attached to the study report, together with the comments and the responses.

Comments and responses

The one ADEME published in 2023, for a study on the deposit for reuse of glass packaging, shows how it works. The panel made around 190 comments on a 145-page draft report, each ranked by importance, accompanied by a proposal and then a reasoned response.

The areas examined closely

A reviewer's comments almost always concentrate on the same areas of the study:

• The functional unit, which describes the service provided, with its lifetime and performance, without which 2 products cannot be compared.
• The system boundaries, where any excluded stage is justified by a quantified cut-off criterion, never by a lack of data.
• The allocation and end-of-life rules, in particular the treatment of recycling, which can shift a result significantly.
• The data, dated and matched to the right country and the right process, with the database version cited, as the expiry of EF 3.1 shows for PEF studies.
• The sensitivity analysis, which varies the most influential assumptions to show whether the conclusion holds.
• The conclusions, which go no further than the results, especially when the difference between 2 products remains smaller than the uncertainty.

What the review changes

A review changes the study. The ADEME panel obtained revised transport modelling and recycling rates aligned with the agency's reference framework. In the Hamac nappies study, one reviewer required a sensitivity analysis using European electricity, because the results were going to be published.

5How long does a review take, and how much does it cost?

Alongside the study or at the end

The review can run alongside the study or take place once the report is written: the Lyon call for projects allows for the 2 options, and the ADEME panel states that its own review was carried out at the end of the study. Started at the scoping stage, it corrects a choice of scope before the whole calculation rests on it.

Lead time

For a standard LCA reviewed by a single expert, allow 2 to 4 weeks, an order of magnitude observed in 2026, depending on the quality of the file and the number of rounds of exchanges. A panel takes considerably longer: in the 2 published reviews in the timeline below, 3 months and nearly 6 months passed between submission of the report to the panel and the final opinion.

Price

There is no public price list. A review by a single reviewer costs, as an order of magnitude observed in France in 2026, between €3,000 and €5,000 excl. VAT, or 2 to 5 days of expert time, varying from one provider to another. A panel costs considerably more, since it pays a chair and several reviewers. The price depends mainly on the size of the model, on access to the model, since rerunning the calculation takes longer than reading a report, and on the number of rounds of exchanges. Published prices, lead times and funding are covered in detail in our article on the price of an LCA critical review.

This budget comes on top of the study itself, detailed in how much an LCA costs, and may be partly funded: see the funding available for an LCA.

6What should you prepare, and how should you mention the review?

The file to hand over to the reviewer

A review moves at the pace of the file. 5 documents let the reviewer scope their work and the commissioner obtain an accurate quote:

• The full study report, with its goal, functional unit, boundaries, assumptions and the limitations the author has identified.
• The model file or a readable export, so that the reviewer can rerun the calculations that support the conclusions of the study.
• The list of data used, with their source, year, country and the version of the database used.
• The intended use of the result: internal decision, response to a buyer, publication of a comparison or environmental product declaration.
• The name of the study's author and of the software used, so that the reviewer can confirm they have no connection with either.

A study on a small budget or a first LCA carried out in-house benefits from being documented beforehand: every unwritten assumption becomes a comment, then a round of exchanges.

The public statement

The public text states who reviewed the study, under which standard and where to read the review report. A statement such as "study reviewed by a panel of 3 independent experts under ISO 14044, review report available on request" is accurate. "Validated" or "certified by" are not. Publishing the review report, the comments and the responses in an annex, as RECYC-QUÉBEC does, is the strongest statement you can make to a buyer and the best protection against unintentional greenwashing.

At Projet Celsius, we find that the most useful of the 5 questions is the last one: what would lead the reviewer to refuse to conclude. We review the report and the model of LCAs carried out by others, and never a study we carried out ourselves. When the use of the result requires a panel or an approved verifier, it is better to know from the first conversation than to commission a review that will not be enough.

7Key takeaways

• An LCA critical review is the examination of a study by an expert who did not carry it out, under ISO 14044, supplemented since 2024 by ISO 14071.
• It is mandatory only for a comparison disclosed to the public, which then goes to a panel of at least 3 members, with no weighting of the indicators.
• An FDES, an EPD or a PEP is checked by a verifier approved by its programme, which is a different process from a critical review.
• A good reviewer has no part in the study, knows the sector, reviews the model as well as the report and delivers a report that keeps the comments and responses.
• Allow 2 to 4 weeks and roughly €3,000 to €5,000 excl. VAT for a single expert, and several months for a panel.

To gauge the budget for the study itself before having it reviewed, see how much an LCA costs.

Further resources

Frequently asked questions

1Is an LCA critical review mandatory?

No, except for a comparison between products disclosed to the public: ISO 14044 then requires a review by a panel of interested parties with at least 3 members. An FDES, an EPD or a PEP, for its part, requires verification by a verifier approved by its programme, which is a different process. Elsewhere, the review is voluntary and often requested by a buyer.

2What is the difference between a critical review and FDES verification?

A critical review assesses the method, data and report of an LCA study under ISO 14044. Verification checks that an environmental declaration complies with the rules of its programme before publication, and only a verifier approved by that programme may carry it out. The 2 are not interchangeable.

3Can a consultancy review its own LCA?

No. Independence requires that the reviewer neither carried out the study nor chose its assumptions. Another consultancy, or an expert with no connection to the study, must do it. The standard accepts a reviewer from within the company if they took no part in the study, but a third party gives more weight to an external reviewer.

4How much does an LCA critical review cost?

There is no public price list. For a standard LCA reviewed by a single expert, the order of magnitude observed in France in 2026 is €3,000 to €5,000 excl. VAT, or 2 to 5 days of expert time. A panel costs considerably more, since it pays several reviewers. Some funding schemes cover the LCA and its review, such as the 2025 call for projects of the Métropole de Lyon, at 50%.

5How long does an LCA critical review take?

2 to 4 weeks for a standard LCA reviewed by a single expert, depending on the quality of the file and the number of rounds of exchanges. A panel takes several months: in 2 published reviews, one by ADEME in 2023 and the other in 2013, 3 months and nearly 6 months passed between submission of the report and the final opinion.

6What should a critical review report contain?

The reviewers' numbered comments, each with its justification and often a proposal, the commissioner's responses, what changed in the study, the names and affiliations of the reviewers and their conclusion. ISO 14044 provides for the review report to be attached to the study report.

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