Is the fire performance of phase change materials a significant barrier to implementation in building applications?

This paper examines the reaction-to-fire behaviour of building materials containing phase change materials by predicting their fire classification according to the European reaction-to-fire classification system (Euroclasses). While various building materials containing PCMs exist today, their application in buildings has been somewhat limited due to the fire behaviour of these building materials. Existing research has focused on small scale testing which does not allow determination of the Euroclass of the material. In this application, large scale performance is predicted based on previously published small scale data to provide some valuable insights into the expected fire performance of these materials. As a starting point, a systematic literature review on phase change materials (PCM) and fire behaviour was conducted, with the purpose of identifying all existing literature concerning experimental investigation of the fire behaviour of building materials containing PCMs. In total, 816 articles were selected from the literature search. After screening of these papers, 51 articles were fully reviewed and included in the next step of the study. In the next step, the reaction-to-fire behaviour of the building materials with PCMs that were identified from the literature was predicted using the ConeTools simulation program. The input data required for ConeTools was obtained from the identified literature. Initially, 27 of the 51 studies used cone calorimetry as a fire testing method and could therefore be considered for the Euroclass assessment. However, of the 27 studies, only 17 studies provided information on both the heat release rates (HRR) and time to ignition (TTI) and were selected for use in the ConeTools program. The ConeTools program predicted Euroclasses for all the building materials containing PCMs from the selected 17 studies. The predicted Euroclasses for most materials was low (i.e. fire classes 'D' or 'E or worse') which confirms that materials containing PCMs generally have a low react-to-fire behaviour even with addition of flame retardants (FR). Our findings indicate that the fire behaviour, typically Euroclass 'D' or 'E or worse', of the building materials containing PCMs is indeed a barrier to their implementation in the building applications where Euroclass C or higher is required, e.g. in evacuation pathways or certain public spaces. The predictions of the Euroclasses based on ConeTools need to be confirmed using Single Burning Item tests (EN 13823) and/or Room Corner tests (ISO 9705) in the future, to enable a better understanding of fire behaviour of these building materials.