Brazil's vastterritory andhugeforested regions have contributed tothewidespread useoftraditional crossarms made ofnative woodspecies indistribution lines. However, this situation ischanging duetotheincreasingly highcostofnative species andBrazil's environmental laws. Inresponse tothese changes, electric powersuppliers havebeenseeking alternatives, andprototypes ofreforested woodcrossarms (such asEucalyptus citriodora) impregnated withpolymer(castor oil-based polyurethane resin) havebeenstudied forapplication as mechanical supports forelectrical powerdistribution systems, withverysatisfactory results. Thispaperdiscusses mechanical andelectrical tests conducted onthis newmaterial undercritical conditions oftemperature andrelative airhumidity. Also presented aretheresults ofelectrical tests conducted atGraz Technology University's Institute ofHighVoltage Engineering andSystem Management inAustria toanalyze thematerial's insulation performance underelectrical stress, particularly under partial discharge during critical operating conditions.