The HSE warns that they may lose integrity after exposure to relatively short duration hydrocarbon pool fires. The time taken for this is considerably shorter than the specified resistance period of 60 minutes derived from the certifying test for cellulosic fires.
Offshore operators are told that they must now determine whether composite gratings, especially fibre reinforced plastic ones, are used in areas with potential hydrocarbon fire exposure. If so, they must identify means of ensuring the safety of personnel should they walk on weakened gratings.
For further details, see the HSE website.