ISO 23693 part 1 aims to simulate the mechanical loads that could be imparted to passive fire protection (PFP) materials and systems by explosions resulting from the ignition of releases of flammable gas, pressurised liquefied gas, flashing liquid fuels or dust that may precede a fire. Explosions can give rise to pressure and drag forces. Damage to PFP materials and systems in an explosion can be caused by the direct effects of pressure and drag loadings and by the resulting distortion of the substrate supporting the PFP material. This part of the ISO 23693 series deals with tests to assess the performance of PFP materials applied to panels, plates etc that could be used as divisional elements. The loading on this type of element predominantly results from the explosion pressure applied and drag loadings are typically minimal.