Academics have released the findings of a research study which has concluded that the panels used on the Grenfell Tower were 55 times more flammable than the least combustible materials available.

The scientists at the University of Central Lancashire (UCLan) conducted the first in-depth study of the cladding and insulation used on Grenfell Tower, uncovering significant differences in flammability and smoke toxicity between the products used and the least combustible products available, helping to explain the rapid spread of flames within the tower’s façade.

The results of the study, published in the Journal for Hazardous Materials, showed that that the polyethylene-filled aluminium composite material (ACM) panels used on the tower were 55 times more flammable than the least flammable panels tested.

Smoke released when burning polyisocyanurate (PIR) insulation was also found to be 15 times more toxic than current fire-safe insulation products, with just 1kg of burning PIR insulation being sufficient to fill a 50m³ room with an incapacitating and ultimately lethal mix of carbon monoxide and hydrogen cyanide gas.

The research also found that the combination of ACM panels and PIR insulation resulted in the highest flammability and smoke toxicity of products currently available. Used together, the ACM forced rapid ignition of the toxic foam.

Just a few burning drips of polyethylene from the ACM panelling would be enough to ignite the foam insulation, which could provide a new explanation for the very rapid spread of flames within the tower’s façade.

Richard Hull, author of the study and Professor of Chemistry and Fire Science at UCLan, said, “Our research demonstrates the need for tighter regulations around flammable and toxic building products, especially when used on towers or buildings with vulnerable occupants, as this could put lives at serious risk”.

Last reviewed 24 January 2019