How to Communicate Sustainability Without Greenwashing

Why vague green language is now a compliance matter

Sustainability communication has moved from stylistic choice to an evidence-based discipline. The UK Competition and Markets Authority estimated that roughly 40% of environmental claims seen online could be misleading, which is why it published a Green Claims Code built on six principles for business. In the United States, the FTC’s Green Guides apply ordinary truth-in-advertising rules to green marketing and require “competent and reliable scientific evidence” to back environmental statements.

In the European Union, the Empowering Consumers for the Green Transition Directive (2024/825, “EmpCo”) adds explicit prohibitions and will bind all business-to-consumer communication from 27 September 2026, after member states transpose it by 27 March 2026. The practical implication: a claim you cannot substantiate in writing is no longer merely risky — in many jurisdictions it is already treated as misleading advertising, and in Russia it may qualify as unfair competition.

The cost of a mistake has three parts: reputational damage, legal exposure, and the difficulty of reconstructing evidence after the fact. That is why credible sustainability talk should be engineered so that every statement can be verified and that verification happens before publication, not in response to a complaint.

• around 40% of online environmental claims may be misleading (CMA estimate)
• the FTC requires scientific evidence for green marketing claims
• EU EmpCo applies to B2C communication from 27 September 2026

The six principles that make a claim defensible

The CMA’s Green Claims Code condenses consumer law into six principles that work as a universal filter, regardless of jurisdiction. A claim must be truthful and accurate; clear and unambiguous; must not omit or hide important information; must involve fair and meaningful comparisons; must consider the full life cycle of the product or service; and must be substantiated. Courts, regulators and advertising standards bodies increasingly reason along the same lines.

Truthfulness means the statement matches reality on the day it is published and does not go stale after a change of recipe, supplier or packaging. Clarity requires that a consumer without specialist knowledge understands which attribute and which scope (product, category or company) is meant. Completeness forbids hiding the conditions that cancel out the benefit — for example, calling packaging recyclable when that is true only in some regions.

Substantiation is the principle that ties the others together: without a written evidence file, even a genuinely sustainable business can be accused of greenwashing. Regulators judge both what is said and whether the proof exists and is accessible, not only the company’s good intentions.

• truthful and accurate
• clear and unambiguous
• no omission of material information
• fair and meaningful comparisons
• full life-cycle consideration
• substantiated claims

What the EU EmpCo Directive changes from September 2026

The EmpCo Directive significantly tightens the rules for green marketing inside the EU. Generic environmental claims — “environmentally friendly,” “climate-friendly,” “eco,” “green” — are no longer allowed unless backed by an acknowledged, outstanding environmental performance, for instance recognised under EU law, by a national or regional ecolabel, or by a top-tier programme. Instead of a vague label, businesses should state something verifiable, such as “100% of the energy used for this packaging comes from renewable sources.”

The Directive also targets claims built on a single attribute that are presented as applying to the whole product, offset-based “carbon neutral” wording, and self-created sustainability labels without external certification. Future-looking promises such as “climate neutral by 2030” are permitted only with a concrete, verifiable implementation plan covering measurable targets, resources, technology and independent verification — a declaration of intent is not enough. Durability and repairability statements carry their own obligations.

The schedule can still change at national level as member states finalise transposition, and the separate EU Green Claims Directive remains in progress, so check the latest official guidance in each market before relying on any deadline. The direction, however, is clear: sustainability communication must be precise, verifiable and transparent.

• bans unsupported generic environmental claims from 27 September 2026
• offset-only “carbon neutral” claims restricted to own value-chain action
• self-created labels without external certification prohibited
• future climate claims need a verifiable implementation plan

ISO 14021: verified versus self-declared claims

International practice, described in the ISO 14020 family of standards, distinguishes three broad types of environmental labelling. Type I labels are awarded by an independent third party against published criteria (often referencing ISO 14024) and are therefore seen as the most credible. Type III declarations present quantified data. The most common case in everyday marketing is Type II: self-declared environmental claims that a manufacturer makes about its own product without external certification, governed by ISO 14021.

ISO 14021 sets requirements for self-declared claims: they must be accurate, verifiable, relevant and not exaggerated, and they should avoid unqualified wording such as “environmentally safe” or “nature friendly.” The standard also defines specific terms and conditions for typical statements about recycled content, recyclability, degradability and similar attributes. This is also the source of the categories of environmental claims that underpin guidance in other markets, including Russia.

The communication takeaway: if you have not gone through independent certification, speak the precise, qualified language of ISO 14021 rather than implying a certified status. If you display someone else’s ecolabel, verify that it is current, applies to this product and was issued by an authorised body — not invented by the brand.

• Type I — independent third-party certification (highest credibility)
• Type II — self-declared claims under ISO 14021 (require evidence)
• Type III — quantified environmental declarations

Rewrite a claim: from adjective to quantified statement

The core practical skill is converting an evaluative word into a concrete, checkable fact. Replace “sustainable packaging” with “at least 80% recycled fibre in this box”; instead of “eco-friendly,” name the attribute actually achieved. Rather than “climate neutral,” describe what has been cut in your own life cycle and explain the role of any offsets without presenting them as equivalent to avoided emissions.

Comparisons demand care: a phrase like “uses less water” must name the baseline, the comparator and the method, otherwise it is treated as misleading. Avoid giving a product or brand a green-sounding name when the benefit belongs to only one component, and never imply approval by an organisation that has not actually endorsed the product.

Make the evidence reachable. A QR code or short link to a page with a plain-language justification, the date and the data source builds more trust than any slogan. The best claims carry their own boundary conditions visibly, for example “energy consumption reduced by 15% versus the 2022 model.”

• replace “eco” and “green” with quantitative criteria
• name the baseline, comparator and method for comparisons
• do not brand a whole product green for one attribute
• publish the proof via a QR code or link

Turn communication into an evidence system

Sustainable talk becomes robust when a company runs a managed register of environmental claims. For each statement, record the wording, the owner, the date of evidence collection, the data source (test report, lifecycle assessment, calculation), the scope (product or whole company) and the next review date. This register is the foundation for fast responses when a regulator, competitor or journalist challenges a claim.

Build the review into the ordinary product launch process: an environmental formulation should be cleared by technical, legal and communications specialists before publication, not after a complaint. If an error still surfaces, the credible sequence is to acknowledge it, correct the message and, where needed, reach those who already saw the advertising. Speed and honesty in correction usually beat defending an inaccurate phrase.

Distinguish general information from professional advice: this article outlines common principles and regulatory landmarks, but the final decision on a specific campaign and the assessment of risk in your jurisdiction remain with your lawyers and specialists. It is also worth tracking regulator updates regularly, because requirements and interpretations in this area are evolving quickly.