Passive fire protections are one of the safety systems which are installed commonly in buildings. As every kind of such systems these protections have to controlled according to legal regulations. To facilitate periodic checks RFID technology can be successfully used. In this paper, thermal behaviour of produced swelling materials suitable for passive fire protection was examined and thermal endurance of RFID tags used to identify these protections was analysed as well. The results achieved in this study showed expected thermal behaviour of the swelling materials which fulfilled the whole space of the protections blocking spreading fire and smoke. Further, it was noticed that a gasket sealant and a high-temperature silicone allowed to decrease temperature affecting RFID tags. Paper-face and hard RFID tags withstood the applied thermal exposure and their readability was restored after cooling down the tags to about 120°C. This means that it is likely that these tags can resist small fire incidents on condition that temperature affecting the tags does not exceed a decomposition temperature of materials used for their production.