Fire rated doors and security doors have completely different functions. Before you begin to specify anything, it is important to understand what each does because one of the two serves the function of fire and smoke containment to allow the safe evacuation of people, while one serves the function of keeping people out. Some doors can serve both functions; however, as a good example, just having a high-security door built to a high standard does not satisfy fire requirements.
What the rating actually signifies
Fire doors are rated by the time they hold back fire (FD30, 30 minute rating; for example, FD60, 60 minute rating, etc). This is not a rough guess; it is certified and tested. The door must be installed with the proper frame, seals and hardware to the door itself for the rating to apply. A fire-rated door that is hung on a wrong frame does not carry its rating.
Where it’s a legal requirement
Building regulations state where fire doors must be installed, and this is dependent on the building design and how it is wrapped around its escape routes and compartments. Fire doors must be installed in areas of risk, such as plant rooms, to delineate those spaces from the remainder of the building. Failure to install fire doors when required is a breach of the law and should be addressed when planning any fit-out or refurbishment as retrofitting a fire door is more disruptive than considering it during the design phase. [internal link: commercial security doors]
Fire-rated and secure
When both fire and forced entry protection is a concern, as it is most often with external doors and high risk internal doors, the door must have undergone a test and received a certification for both. A fire resistant door does not guarantee resistance to attack, and vice versa, so it is important to verify the two.
This is important to get right as a fire door could be modified, drilled and penetrated, and loose its fire resistance. Getting this right is a compliance requirement, but also a matter of safety.