"The cladding used on Grenfell Tower burnt 10 times faster than a sister product in a safety test conducted more than a decade before the deadly fire, but its manufacturer did not notify customers and continued selling the more flammable variant until after the blaze.
The failure to disclose the test results came to light on Tuesday at the inquiry into the 2017 fire at the London block of flats, in which 72 people died.
The inquiry was shown a document from 2004 which described the relative fire safety performance of two variants of Reynobond PE cladding sold by Arconic Architectural Products, the French subsidiary of US company Arconic, which supplied cladding to Grenfell: one in bent “cassette” form, the other a flat “riveted” panel.
The tests were carried out in France and found that the cassette version of the product burnt 10 times faster than the riveted version, producing seven times more heat."
FT.com