Fire resistance of polyethylene is realized by magnesium hydroxide which is distinguished from halogenated fire-proofing agents by its lower cost and its non toxicity. Magnesium hydroxide decomposed by an endothermic reaction with liberation of water, contributing to fire proofing. The sample used (Kisuma 5A-N*) is constituted from a powder (0.6-0.8 micrometre) its surface is treated by plastic material in order to ameliorate its compatibility. We studied the thermal decomposition by DTA and TG, of mixtures constituted by polyethylene and magnesium hydroxide. A sudden decomposition began at 385-degrees-C for pure polyethylene and decomposition took place at 429-degrees-C for the mixture polyethylene-Kisuma (50-50). Incorporation of magnesium hydroxide in polyethylene increases fire resistance.
