It depends on the fire load: How long was the blanket exposed to how high temperatures? Has it possibly been mechanically damaged, i.e. has cracks or holes?

We have observed that sometimes the silicone coating reacts and white spots are seen. A perfectly normal reaction where the silicone coating burns into the fiberglass. The function of the ceiling is not affected!

Cracks and holes up to the size of a handball do not negatively affect the effectiveness of the blanket.