Whenever a fragment of the host adheres to his fingers, especially after the fraction or the Communion of the faithful, the priest is to wipe his fingers over the paten or, if necessary, wash them. Likewise, he should also gather any fragments that may have fallen outside the paten.
The sacred vessels are purified by the priest, the deacon, or an instituted acolyte after Communion or after Mass, insofar as possible at the credence table. The purification of the chalice is done with water alone or with wine and water, which is then drunk by whoever does the purification. The paten is usually wiped clean with the purificator. Care must be taken that whatever may remain of the Blood of Christ after the distribution of Communion is consumed immediately and completely at the altar.
If a host or any particle should fall, it is to be picked up reverently. If any of the Precious Blood is spilled, the area where the spill occurred should be washed with water, and this water should then be poured into the sacrarium in the sacristy.