"The higher castes consider even the physical contact of an ?untouchable? with their food as polluting" (Anant 1972:73). It was as if they were infected with a highly contagious disease. If a member of a high caste does come into contact with a member of the untouchable class they would do everything possible to remove that pollution from them. For example, "Traditionally, if a caste Hindu would come into physical contact with an untouchable, he would consider himself polluted and would take a bath and sometimes even wash his clothes to remove pollution" (Anant 1972: 66) Other castes did their best to stay away from the untouchables.
Also if even an untouchables shadow fell on a Brahman, the untouchable would be punished.