Q: I am a priest and was recently given a set of 3 holy oils. Each phial of oil is labeled: OI, OC, and SC, I’m confused about the differences between the three types of oils, as well as how to tell which is which. Can you please help?
A: Thankfully you are in luck. I can help you with some Latin, as well as other details! The three types of oils are the three traditional holy oils of the Church.
- Oil of the Sick (OI, Latin for oleum infirmorum): This oil is used for any general anointing of a sick person, as well as during a public healing rite. The form for blessing of this oil can be found on p. 455 of the Book of Common Prayer, and this may be done by a priest.
- Oil of the Catechumens (OC or sometimes OS, oleum catechumenorum or oleum sanctum): This oil is probably used less commonly, but it is traditionally associated with the anointing of a baptismal candidate, and it occurs within the baptismal rite itself, at the Presentation and Examination of the Candidates and before the actual water bath. Its origins can be traced back to anointing while saying a prayer of exorcism immediately before the baptism with water. An example of how this oil may be used within the Episcopal rite of Holy Baptism, with appropriate words, may be found in A Priest’s Handbook: The Ceremonies of the Church by Dennis Michno.
- Oil of Chrism (SC, sacrum chrisma or sanctum chrisma): This oil must always be blessed by a bishop. Often, this is done at a Chrism Mass during Holy Week, or a similar service that includes a renewal of ordination vows for diocesan clergy gathered together. This oil is used to anoint the newly baptized.
Some helpful hints to remember when looking at the Latin initials: OI (think infirm, the sick), SC (always refers to chrism), and then anything else is OC/OS.