EPS is a combustible material which by the inclusion of a flame retardant can achieve a Reaction to Fire performance of Euroclass E. Products with this classification have a reduced flame spread. Full details on the fire properties of EPS are detailed in BS 6203 Guide to fire characteristics and fire performance of expanded polystyrene materials (EPS and XPS) used in building applications.
However in construction EPS should always be protected from source of fire by such as brickwork or plasterboard in walls or cementitious screeds in the case of floor applications.
Further information can be found in the booklet Fire Safety Briefing – EPS insulation.
British Plastics Federation