In Peru the plastics industry generates plastic waste of which only 50% are recycled. Likewise, fluidized catalytic cracking units annually produce significant amounts of catalyst that must be disposed as a solid residue. In this investigation, three samples of plastic waste from urban solid waste, a sample of fresh catalyst and another of FCC equilibrium catalyst were characterized, the equilibrium catalyst sample was heat treated to restore its catalytic properties and characterized with and without previous treatment. The characterization was performed by FTIR analysis and thermogravimetry. It was determined that the three samples of plastic waste analyzed were High Density Polyethylene (HDPE) and it was found that one of the three samples has a different thermogravimetric behavior because its maximum decomposition temperature is different. Likewise, it was determined that the fresh catalyst of Fluidized Catalytic Cracking (FCC) has a different chemical structure and thermogravimetric behavior than the treated and untreated equilibrium catalyst (E-Cat) samples. It is concluded that the samples of plastic waste are HDPE and have potential for use as a load of thermochemical processes, also the E-Cat have potential as catalysts in these processes.