A new report from the Office for Product Safety and Standards (OPSS) has revealed widespread compliance failures across manufacturers of heat soaked thermally toughened glass, raising serious questions for the glass and glazing supply chain.

Published on 5 March [2026] the findings of OPSS inspections found that every single heat soaked insulated glass unit assessed failed compliance checks.

Only half of the companies inspected were able to produce any form of Declaration of Performance at the point of inspection – a legal requirement on every manufacturing business.

A further 93% failed to meet labelling requirements and 86% could not demonstrate compliance with marking requirements.

For IGU manufacturers, glass processors and fabricators, the implications are significant. Established following the Grenfell Inquiry, OPSS has the power to stop the supply of products to the market where compliance cannot be demonstrated.

Kevin Jones, head of technical at the Glass and Glazing Federation (GGF), warned the headline figures should act as a wake-up call for the sector.

“We have to be very clear. The findings of the OPSS are absolutely unacceptable and we welcome the work that it is doing,” he said.

“What OPSS has uncovered is not a systematic attempt to produce unsafe glass, but a systematic failure to maintain the evidence that proves products are safe and compliant.

“In too many cases the glass itself was fine, but the declarations, labelling and conformity marking were incomplete, out of date or simply non-existent.
That is a completely unacceptable gap in process and one that has the potential to shut down production.”

OPSS inspections found that some manufacturers were unable to produce the legally required Declaration of Performance, while others could not demonstrate that their products had been tested against the relevant performance standards.

In others there was no evidence of initial type testing or records to confirm that required factory production control tests had been carried out.

“The headline figures sound alarming, but they do not mean that every pane of glass being produced is unsafe,” Kevin continued.

“What they show is that businesses have allowed their conformity systems to decay. Old managing director signatures on critical documents, outdated standards references, missing labels and missing declarations.

“All of those things are enough to trigger enforcement action. If something goes wrong on site and you do not have that documentation, you do not have a leg to stand on.”

Under the Construction Products Regulations, manufacturers must maintain technical documentation, operate factory production control systems and issue Declarations of Performance for products placed on the market. Without this evidence regulators can prevent products from being supplied.

The GGF is urging IGU manufacturers, glass processors and fabricators to review their conformity systems now rather, than waiting for enforcement action.

“This isn’t just an issue for IGU manufacturers, it applies to fabricators – and in certain circumstances, installers too.

“If records, test evidence and declarations from manufacturers to demonstrate that the product supplied has been properly processed and tested is missing or wrong, then the legal safety net disappears.

“Production can be shut down, or if failure relates in a far more significant failure of safety, then the consequences are infinitely greater.”

GGF Consulting is already working with IGU manufactures, glass processors and fabricators, to audit documentation, rebuild technical files and ensure that Declarations of Performance and labelling systems remain current and compliant.

“In some cases that means starting from almost nothing. In others it means tightening up systems that were good in 2013 but have not kept pace with product changes.

“What we are not doing is simply issuing bits of paper. We are helping businesses create living systems that will stand up to OPSS scrutiny.”

For support, contact the GGF Consulting team at [email protected] or visit www.ggf.org.uk
The full OPPS report can be found here