A permanently deactivatable security tag and method to create a permanently deactivatable security tag to eliminate tag pollution caused by reactivated tags reentering a store premises and setting off false alarms. The security tag includes a frangible conductive portion that fractures due to stress applied on the frangible conductive portion from a hardened substrate located on the tag. The hardened substrate induces stress to the frangible conductive portion located adjacent to the edge of the hardened substrate as the tag is flexed and bent. The fracture of the frangible conductive portion of the tag results in a shifting and/or disabling of the predetermined frequency of the security tag.