The Advertising Standards Authority (ASA) has today published a revised Ruling relating to two historical advertising claims that previously appeared on the Stove Industry Association (SIA) website. This follows an Independent Review which identified a substantial flaw in part of the original published assessment, resulting in the case being reopened and reinvestigated.
The revised Ruling relates to two historical claims about modern wood burning stoves that appeared on the SIA website in 2025.
While the ASA’s overall decision that the original advertising claims required greater qualification remains unchanged, the published assessment has been substantially revised following the Independent Review process. The revised assessment includes clarification of the interpretation of technical emissions evidence and the limitations of the National Atmospheric Emissions Inventory (NAEI) when comparing the performance of individual appliance types.
Why did the SIA request an Independent Review?
Following publication of the original ASA Ruling in November 2025, the SIA carefully reviewed the published assessment.
The Association accepted that the ASA was entitled to conclude that the advertising claims would have benefited from greater qualification. The original claims were removed from the SIA website following publication of the Ruling, and the Association reviewed its internal communications processes.
However, the SIA was concerned that elements of the published reasoning extended beyond the wording of the advertising claims into technical interpretation of emissions evidence. It therefore exercised its right to request an Independent Review of the published assessment.
What did the Independent Reviewer conclude?
In March 2026, the Independent Reviewer concluded that the published assessment contained a substantial flaw.
In reaching that conclusion the Independent Reviewer agreed with the SIA that the ASA’s interpretation of the NAEI data during the original investigation was incorrect. The Reviewer noted that the ASA had accepted its original interpretation of the dataset was incorrect because it had treated aggregate national emissions data as though it represented emissions on a per-appliance basis.
The Reviewer also concluded that the original assessment risked misleading consumers and was potentially unfair to the SIA, and recommended that the case be reinvestigate and reconsidered by the ASA Council.
What has changed?
The revised Ruling includes a number of important changes to the published assessment.
In particular, it now explains that the NAEI data represents aggregate national emissions by source category and fuel type and does not provide direct per-appliance comparisons between modern stoves, older stoves and open fires. It also provides a revised assessment of the additional technical evidence submitted during the investigation.
The revised Ruling therefore provides a more accurate explanation of the evidence considered during the investigation.
What has not changed?
The revised Ruling does not change the ASA’s overall decision that the original advertising claims required greater qualification.
The SIA has consistently acknowledged that advertising claims should be expressed clearly and that consumers should understand exactly what is being claimed.
The Independent Review did not overturn the outcome of the investigation. Instead, it addressed the reasoning contained within the published assessment and resulted in that assessment being substantially revised.
SIA statement
The revised assessment no longer contains statements from the original Ruling suggesting that National Atmospheric Emissions Inventory (NAEI) data demonstrated that a modern Ecodesign stove emitted more PM2.5, carbon monoxide, methane and sulphur dioxide emissions than an older stove and more sulphur dioxide, carbon monoxide and “several other toxins” than an open fireplace when burning dry wood.
Erica Malkin, Executive Director of the Stove Industry Association, said: “The SIA has always supported clear, accurate and evidence-based communication with consumers. Throughout this process we accepted that the wording of the original advertising claims could have been clearer and, following the original Ruling, we removed the claims from our website and reviewed our communications. Our concern related not to the ASA’s role in regulating advertising, but to aspects of the published reasoning that interpreted complex technical evidence in a way that we believed could create an inaccurate understanding of the comparative performance of modern stove technology.
“The Independent Review process exists precisely to address situations where there are concerns about the reasoning underpinning a published ruling. We are therefore pleased that the process has resulted in a revised assessment which accurately reflects the evidence that was considered. Accurate interpretation of technical evidence is important for everyone — consumers making informed choices, policymakers developing future policy, and organisations such as ours that are committed to promoting best practice and continual improvement across the sector.”
Andy Hill, Chair of the Stove Industry Association, added: “Independent review is an important part of good regulation. We welcome the fact that the process has worked as intended and we remain committed to supporting clear advertising standards and accurate interpretation of technical evidence.”
Timeline of events
5th November 2025 – ASA publishes original Ruling
17th November 2025 – SIA requests Independent Review
6th March 2026 – ASA Independent Reviewer identifies a substantial flaw and recommends the case be reopened
8th July 2026 – ASA publishes revised Ruling
Downloads
The following documents are available to download:
The SIA remains committed to promoting clear, evidence-based information for consumers and will continue to work constructively with government, regulators and stakeholders to support improvements in air quality and responsible use of modern stove technology.
