1) Even before eating those fruit and vegetables which are washed only for purposes of cleanliness, if one eats them when they are still wet one must wash one’s hands. However, a food which one does not normally dip in liquid and which is not normally wet, does not necessitate hand washing, even if for some reason it became wet. The reason for this is that the Rabbis did not decree hand washing for something which is uncommon. (Mishne Berura 158)
2) One who eats less than a KeZayis of food dipped in liquid, does not need to wash his hands. (ibid)