The report on the Grenfell Tower fire that killed 72 people has found that Irish company Kingspan knowingly created a "false market" in insulation for use on buildings over 18 metres in height.
Kingspan's K15 insulation product made up around 5% of the insulation in the tower block and was used without the company's knowledge.
The report found that the principal reason for the fire spread was cladding, which was not made by the Co Cavan-based Kingspan.
The inquiry concludes that Kingspan had made a "false claim" about its product's suitability for use in the external wall of any building over 18 metres in height regardless of its design or other components.
The report states that the development and marketing of K15 for use on buildings of over 18 metres in height between 2006 and 2019 was one of "deeply entrenched and persistent dishonesty on the part of Kingspan in pursuit of commercial gain coupled with a complete disregard for fire safety."
"As Kingspan knew, K15 could not honestly be sold as suitable for use in the external walls of buildings over 18 metres in height generally, but that is what it had succeeded in doing for many years," the inquiry concluded.
The report describes as "disastrous" tests performed in 2007 and 2008 on systems incorporating the then current form of K15, "but Kingspan did not withdraw the product from the market, despite its own concerns about its fire performance," it states.
The inquiry found that Kingspan concealed from compliance certification organisation BBA the fact that the product it was selling, to which the certificate issued in 2008 referred, differed from the product that had been incorporated into the system tested in 2005.
"Moreover, the BBA certificate contained three important statements about the fire performance of K15 that were untrue. It used a form of words suggested by Kingspan and drawn from its own marketing literature," the report states.
The inquiry concludes that Kingspan succeeded in obtaining from the Local Authority Building Control (LABC) a certificate that contained "false statements about K15" and supported its use generally on buildings over 18 metres in height.
The report said Kingspan "cynically exploited" the industry's lack of detailed knowledge about insulation and cladding fire safety tests, and "relied on the fact that an unsuspecting market was very likely to rely on its own claim about the product".
The inquiry concludes that the "dishonest strategies" of Kingspan, and another company Arconic, succeeded in a large measure due to the incompetence of the compliance certification organisation BBA.
Kingspan's response
In a statement responding to the findings, Kingspan said it extended its deepest sympathies to those impacted by the tragedy.
The company said it welcomed the publication of the report which it described as "crucial to a public understanding of what went wrong and why."
"It explains clearly and unambiguously that the type of insulation (whether combustible or non-combustible) was immaterial, and that the principal reason for the fire spread was the PE ACM cladding, which was not made by Kingspan," the company said.
"Kingspan has long acknowledged the wholly unacceptable historical failings that occurred in part of our UK insulation business."
"These were in no way reflective of how we conduct ourselves as a Group, then or now. While deeply regrettable, they were not found to be causative of the tragedy," Kingspan said.
The company added that it has already addressed these issues, including the implementation of measures to ensure its conduct and compliance standards are "world leading".
We need your consent to load this rte-player contentWe use rte-player to manage extra content that can set cookies on your device and collect data about your activity. Please review their details and accept them to load the content.Manage Preferences
Ulster Rugby
Kingspan is the sponsor of Ulster Rugby.
In a statement, Ulster Rugby said it noted the comments expressed in the report published today, along with its detailed findings.
"Our thoughts are with all those affected by the Grenfell Tower fire," a spokesperson said.
"As was announced at the beginning of the year, Kingspan's sponsorship of Ulster Rugby will come to an end in June 2025, following an agreed 12-month transitionary period," they added.
Companies named in report should 'reflect fully' on findings - Taoiseach
Taoiseach Simon Harris has meanwhile urged companies named in the report on the Grenfell Tower fire to "reflect fully" on its findings.
Asked during his visit to Kyiv if he has any concerns about buildings in Ireland after Kingspan was named in the report, Mr Harris said: "I need to be careful on this because I haven't read the Grenfell inquiry report that came out relatively recently.
"I want to obviously, again, remember those who died in the Grenfell tragedy.
"I think of their families today and think how painful today must be.
"I'm also conscious that they would have waited a very long time for this final report.
"I will take the time to read it, to reflect on it with my officials to see if there are any learnings for Ireland, and I would obviously encourage any company referenced in the report to do likewise, to reflect fully on those findings, and once I've done that I will give a more considered response."
Additional reporting Colman O'Sullivan
