Strategies for fire retarding ethylene vinyl acetate copolymer (EVA) in electrical cable insulation by means of halogen-free systems were explored. Attempts to increase char yield, promoting crosslinking of double bonds either created by deacetylation of vinyl acetate units or by dehydrogenation of ethylene sequences in EVA were carried out. Pd catalysed dehydrogenation was unsuccessful, whereas oxidative dehydrogenation seems promising as shown by using thermally decomposing KMnO_4. On the other hand organic peroxides failed to increase the rate of crosslinking of deacetylated units. Better results were obtained with the addition to EVA of an intumescent system which is a combination of melamine phosphate and phosphate-phosphonate substituted trimethylamine. EVA was shown to play a substantial role in the intumescence phenomenon.
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