Untouchability is the worst part of the Jati System. Jati system imposes severe social controls and restraints on the lower castes. The suddha-asuddha (Purity- Pollution) concept is behind this heinous system. Those who are outside the Jati system were considered untouchables. They are impure. Even their touch can pollute members of other Jatis. If the Untouchables touch members of the Upper Castes, they would be given severe punishments. Those who were touched by the Untouchables had to undergo complex purification processes.