The retardation properties of diammonium phosphate (DAP), ammonium sulfate (AS) and a mixture of huntite/hydromagnesite minerals were studied on particle foliar combustion of Pistacia lentiscus L. (Mastic tree) collected from wildland/urban zones near Athens. Two methods were employed for this study. The first is thermal analysis (TG, DTG, SDTA), that uses samples of 15-17 mg under oxygen atmosphere conditions to favour complete combustion. The second is a laboratory-scale method (similar to the one described by the 79/831 European Commission Directive for testing relative self ignition properties of solid materials), that uses samples of 2.5 g under static air conditions and low heating rate to ensure smoldering combustion. Both methods concluded that DAP and AS are the most effective retardants, with each presenting better performance at different properties, while the minerals are the least efficient ones.