Thanks for the reply Anthony.
Flat was built in 2006 - does that make a difference?
I find in some areas Scottish Technical Handbooks are vaque.
My existing doors have intumescent seals; however, jamb mounted closers, hinges and latches/locks don't bare BS 1154, BS 1935 and BS 12206 stamps.
The installation is also poor as doors do not maintain 3mm gaps and there are no labels present; therefore, my conclusion is that they are not fire doors, but the inclusion of 10x4 intumescent smoke seals through a spanner in the works.
Any further information would be very helpful - cheers!