Catechism of the Catholic Church
1256 The ordinary ministers of Baptism are the bishop and priest and, in the Latin Church, also the deacon. 57 In case of necessity, anyone, even a non-baptized person, can baptize, 58 by using the Trinitarian baptismal formula. The intention required is to will to do what the Church does when she baptizes, and to apply the Trinitarian baptismal formula. The Church finds the reason for this possibility in the universal saving will of God and the necessity of Baptism for salvation. 59
English Translation of the Cathechism of the Catholic Church for the United States of America © 1997, United States Catholic Conference, Inc.