I'm not sure Suit, but there are reports that the cladding could have produced hydrogen cyanide.
This is taken from the Scotsman:
"A highly toxic gas released by insulation on the outside of the building is believed to have contributed to a number of deaths.
The boards, fitted during a refurbishment of the tower, could have produced enough deadly hydrogen cyanide to fill every flat, it has been reported.
Richard Hull, professor of chemistry and fire science at the University of Central Lancashire, told Sky News: “The outside wall of the building had 150mm of PIR foam (fitted), and once the fire had spread to that every flat would have its own source of PIR foam, which would have produced enough hydrogen cyanide to kill all the people in that flat.”
Manufacturer Celotex stated that the insulation would have released “toxic gases” if it caught fire.
King’s College Hospital confirmed to Sky News that three of its 12 Grenfell patients were treated with the hydrogen cyanide antidote Cyanokit."
Scotsman article