the organic polyphosphorus compound cyclic phosphonate esters reacted together to for a melamine salt of organic polyphosphorus compound the component are melt kneaded until they are thoroughly mixed then pressed into a mold producing samples of 1 16 34 to 1 8 34 thick the samples are cut into 1 2 34 strips then flame tested while in a verticle position a 4 34 bunsen burner flame is placed on the bottom of the sample for two 10 seconds and they did not catch on fire the melted drippings did not catch on fire example 31 is modified wherein the melamine and cyclic phosphonate ester are first reacted then cooled and pulverized into a powder then added to the polypropylene pellets example 31 is modified wherein 3 parts by weight of zinc borate 5 parts by weight of ammonium polyphosphorate and 3 parts by weight of a comb like polymer consisting of a polyethylene main chain and a polyoxyalkylene side chain are added to the polyproplene pellets example 31 is modified wherein another thermoplastic resin is used in place of polyproplylene and selected from the list below ______________________________________a polyethylene b nylon polyamide c polyvinyl acetate d ethylene vinyl acetatecopolymer e polyester resin f polyvinylidene chloride g polyurethane.