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Grenfell insulation firm had document warning its product could cause ‘dense, acrid smoke’ leading to ‘incapacitation and death’

News27.02.2312.30 PM by Peter Apps

The parent company of the firm which manufactured and sold the insulation used on Grenfell Tower had a document written at least seven years before the fire warning it could “generate a large volume of dense, acrid smoke when first exposed to fire” which may “bring on the onset of incapacitation and death”.

Picture: Lucy Brown

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At least seven years before the fire, a document warned the parent company of the firm which manufactured and sold the insulation used on Grenfell Tower it could “generate a large volume of dense, acrid smoke when first exposed to fire” #UKhousing

New documents, released by the Grenfell Tower Inquiry last month following a request from Inside Housing, detail the due diligence work carried out by Saint-Gobain before it entered the insulation market in the UK by acquiring Celotex.

Celotex would go on to target its combustible polyisocyanurate (PIR) insulation for use on high-rise buildings. Grenfell Tower was one of its first big jobs.

The fire at Grenfell Tower killed 72 people after it ripped through the building in June 2017.

The documents include an appraisal of the UK market, which a witness statement from a Saint-Gobain manager said was produced before 2010.

It said the market for plastic insulation boards in the UK was likely to reach £1bn by 2020, thanks to more-stringent requirements for energy efficiency.

At the time, Saint-Gobain only sold non-combustible insulation through its subsidiary Isover, but was planning to acquire Ipswich-based Celotex, which made plastic foam products.

The toxic smoke files: new Grenfell inquiry evidence reveals knowledge of risks before deadly blaze

The due diligence document contained a detailed section on fire performance. It said: “Smoke generation is however a major issue. PIR generates a large volume of dense, acrid smoke when first exposed to fire.”

Noting that the plastic could also produce cyanide when burned, it said: “[This] can incapacitate victims quickly… it is possible that it may work in synergy with carbon monoxide to bring on the onset of incapacitation and death.”

In response, a Celotex spokesperson told Inside Housing the reports revealed “nothing new”, as the risk of smoke from burning insulation was “understood” in the construction industry.

They added: “PIR can be used safely in buildings and has been for many years.”

Inside Housing revealed last month that Saint-Gobain and Celotex were researching smoke toxicity in January 2016, with a report noting that its PIR insulation produced more toxic smoke in a fire than other insulation products.

Nonetheless, it remained on the market and was targeted specifically at high-rise buildings.

Other documents released by the inquiry include reports produced by Celotex and Saint-Gobain in this period which show risk assessors for the firm speculating about the potential for new regulations to influence the market for PIR insulation.

“In the case of a large fire disaster with PUR [polyurethane]/PIR identified as aggravators, stricter regulatory measures are expected,” read one such document produced in 2011.

The document also considered the risk of “mandatory smoke toxicity testing” which would “add a burden” to the use of the foams. It said this was also not a major risk to entering the market, as “toxicity standards are too hard to assess in buildings” and “no change in the regulation is expected before 10 to 15 years”.

It said the UK government department responsible for the regulations had been contacted by Alcimed, the consultancy.

It included a quote from the department’s “principal construction professional”, which said: “It is hard to imagine a situation where we would ban the use of PIR or PUR for fire safety reasons.”

The quote adds that “there is always the possibility we might vary our guidance on where combustible materials can be used”.

At the time, the role of principal construction professional was held by Brian Martin, the civil servant who gave days of evidence at the inquiry last year. He was not asked about this presentation and is not directly named in the presentation as the source of the quote.

A further set of slides, produced in January 2014, notes that there was “no regulation” and “no major general concern” on the issue at the time.

But it added if there was a “fire with catastrophic balance”, then “regulation will probably dramatically change”, noting that this could take “less than five years” from the event to happen.

While combustible insulation was banned for use on tall buildings after the Grenfell Tower fire, there are still no specific restrictions on smoke toxicity in the UK market.

The documents released by the inquiry also include an email exchange between staff at Kingspan, a rival manufacturer that produced a small amount of the insulation used on the tower.

Discussing their response to a government consultation on building regulations in September 2017, three months after the Grenfell Tower blaze, a staff member wrote: “We should not suggest that there is a gap in guidance as that implies that it needs filling.”

A previous draft by another member of the team had said “a gap in guidance that should be looked at relates to smoke in fires”.

Providing a new suggested wording, he added: “The new text below is inviting them to see if there is a gap and intends to suggest that there isn’t.”

His notes added that Kingspan would “need to build a case against” the “suggestion from some manufacturers with a vested interest that we should only use non-combustible or limited combustibility materials on facades”.

It suggested that Kingspan should “pose the question of whether [the choice of cladding products on Grenfell] was all down to oversight, ignorance, lack of clarity or wilful omission”, rather than call for a ban.

In response, a spokesperson for Kingspan said that an inquiry expert, Professor José Torero, had also advocated against a combustibles ban, as it would not guarantee safe facades, with a better approach being to improve the competency of the professionals involved.

The spokesperson added: “These are precisely the points Kingspan was making.”

While expert evidence to the inquiry clearly established that most of the victims at Grenfell Tower died from smoke inhalation, where this smoke came from remains contested.

Smoke was produced by the cladding materials, including the insulation, burning on the external facade, and by the contents of flats inside the building.

A study sponsored by Kingspan concluded last year that the contribution of furniture was the “dominant” cause of the smoke inside the building.

But an inquiry expert said that, during the early stages of the fire in particular, “the cladding and insulation was the main fuel burning as a source of smoke”. He said the cladding panels – metal sheets bonded together with polyethylene – and the insulation boards would have contributed “approximately equal” amounts of smoke.

Debris from the external cladding has been found in soot deposits inside the tower, proving that the smoke from the external fire did penetrate into the building.

A Celotex spokesperson said: “Celotex was acquired by the Saint-Gobain Group in August 2012. Celotex had been manufacturing and supplying building products since 1925, and, at that time, supplying PIR for almost 40 years.

“Prior to entering the PIR market, Saint-Gobain undertook extensive work to consider all aspects of the properties and performance of PUR/PIR insulation, which were products already used widely in the market. As is industry best practice, Saint-Gobain commissioned specialist consultants to consider, amongst other things, PIR’s thermal and mechanical properties, fire performance and characteristics that go to health and safety throughout the product’s life cycle.

“The information which Saint-Gobain gathered through this exercise was not new. In particular, it is understood in the construction industry that any product which is carbon based (including PIR) will burn under certain conditions and will release gases if it does so. These include carbon dioxide, carbon monoxide and, where products contain nitrogen, hydrogen cyanide. Saint-Gobain is continually looking for ways in which its products might be improved, and further work was done in that context after the acquisition of Celotex.

“Celotex RS5000 PIR insulation (supplied through distributors) was one of the components used in the Grenfell Tower rainscreen cladding system. Celotex was not part of the design or construction team on the Grenfell Tower project. Celotex does not design, supply or install cladding systems. It does not install insulation and did not do so at Grenfell Tower.

“The fire was, tragically, of a size which meant that smoke and fumes were released from a wide variety of building materials and from the contents of the flats.

“PIR can be used safely in buildings and has been for many years. The relevant properties of PIR, including reaction to fire properties, were referred to in Celotex’s health and safety datasheet, to which readers of its website and product literature were directed, and was information to be taken into account in deciding whether and how to use the product.

“Celotex, and the Saint-Gobain Group, reaffirm their deepest sympathies to everyone who has been and continues to be affected by the fire.”

Asked about the issue of toxic smoke during the fire, a Kingspan spokesperson drew attention to the fact that the smoke toxicity expert had said he “did not consider [Kingspan’s] phenolic insulation at all” in his calculations, because “we understood that it was a very small percentage of what was on the tower”.

In its closing statements, the firm said this showed the inquiry had “no evidentiary basis to conclude that K15 was a source of any toxic gases inhaled by any occupants of the tower”.

It also said that, even in the early stages of the fire, there were multiple flat fires which were releasing smoke from furniture in addition to the smoke, and referred to the January 2022 research it sponsored, referenced above. This study found that the contribution to the smoke from furniture was likely to be “dominant a few minutes after window breakage, when the apartment contents ignite”.

It claimed that the expert, Professor David Purser, had “grossly overestimated” the contribution of the Celotex insulation in the early stages, saying “he (wrongly) assumes that all missing PIR was burnt in this period” when, it claims, it was in fact burned over a longer period of time.

There is no evidence on the long-term health effects of inhaling smoke like that generated during the Grenfell Tower fire, although the coroner investigating the blaze has called for survivors to receive regular health monitoring. This has not yet been put in place.

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Grenfell insulation firm had document warning its product could cause ‘dense, acrid smoke’ leading to ‘incapacitation and death’

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