The aim of this work was to present some results of the characterization of polymers insulators during their degradation, which are used in transmission threads of 69 kV. The intention was to develop performance requirements for these products. A comparative study was done among products collected in the experimental field and the new products artificially aged in laboratory, according to the methodologies applied to polymers. Elastomeric silicon and ethylene–propylene diene rubber (EPDM) blankets were also prepared in the same way as the insulating and investigated. Based on the obtained results, it was suggested some performance requirements that may be utilized during the acquisition of these products by the dealership. In this paper, the results that induced the adoption of the performance requirements studied will be presented, in addition to the standards already utilized for product qualification.