All plastic materials are flammable to some degree, and will catch fire in presence of exterior flame.
The ignition temperature of polycarbonate sheets is 915ºF (490ºC).
The ignition temperature of PVC sheets is 736ºF (391ºC).
Both materials are self-extinguishing, and fire will decay when the exterior flame source is removed.
Note that compared to polycarbonate and PVC, acrylic sheets (which are not produced by Palram) are more flammable.