Firestop material

A firestop material comprising:

• a polymer foam containing no halogenated compound;
• and
• flame-retardants that form a cohesive charred layer on the foam surface, for a temperature corresponding to that of a fire, the flame retardants comprising:
• at least one physical charring agent comprising at least one mineral chemical compound taking a foliated structure and able to exfoliate with the heat, the at least one mineral chemical compound being free of expansible graphite,
• wherein the at least one physical charring agent forms, by itself and in the absence of any interaction with any other constituent of the firestop material, a charred layer,
• at least one reactive charring agent that forms, by reacting with the polymer of the foam, a charred layer on the material surface, and
• at least one inorganic flame retardant comprising a mineral filler and a metal oxide whose decomposition, under the effect of a temperature corresponding to that of a fire, is endothermic, wherein the inorganic flame retardant is such that the mineral filler can melt at high temperature and form a skin and an endothermic-decomposition compound of the metal oxide stabilizes the skin, and
• wherein the physical charring agent, the reactive charring agent and the inorganic flame retardant intervene at different stages of the attack by the fire or the temperature on the firestop material, successively as the temperature increases.