Holy Oil

The typical container used for holy oil.

Holy oil is a rare substance. Castiel obtains some from Jerusalem, in order to use it to restrain Raphael. When the oil is ignited, its flames will trap angels and archangels, if an angel touches or attempts to pass through the flames they will die.

Sam describes it as "a devil's trap for angels" but it differs because angels can still use some of their powers while trapped within the flames. Sam and Dean keep bottles of the oil in the trunk of the Impala, each of which was presumably supplied by Castiel.

It is also discovered that holy oil is one of the components needed in order to see hellhounds. Dean scorches two pairs of glasses in holy oil fire.

Holy fire is capable of hurting, though not killing demons. Castiel throws Meg onto a ring of holy fire to escape and Sam douses Abaddon in holy oil and sets her on fire. Both are not killed, but Abaddon is left in so much pain she abandons her meatsuit and flees.

Episodes

5.03 Free to Be You and Me

Castiel and Dean trap the archangel Raphael inside a ring of burning holy oil and ask him for God's location. He claims that God is dead, and refuses to cooperate. They leave him in the still burning circle. He eventually escapes.

5.08 Changing Channels

Sam and Dean use it to trap the Trickster, forcing him to reveal that he is actually the archangel Gabriel. Dean releases him by turning on the fire sprinklers.

5.10 Abandon All Hope...

Lucifer uses it to trap Castiel, but he manages to break the circle and escape by throwing Meg on the flames. The extent of her injuries was unclear, but she survives.

5.22 Swan Song

Castiel - with a cry of "Hey assbutt!" - uses a molotov cocktail of holy oil to momentarily banish Michael.

6.03 The Third Man

Dean traps the angel Balthazar in a circle of holy oil and forces him to return the soul he bought from a boy, Aaron Birch, with a piece of the Staff of Moses. Castiel causes the circle to vanish with a gesture when he wishes to free the angel.

6.20 The Man Who Would Be King

Dean, Sam and Bobby trap Castiel in a circle of ignited holy oil and force him to admit to working with Crowley. Castiel tells Dean, Sam and Bobby to leave him when the sound of an approaching storm of Demons is heard. They leave, and only Crowley enters; he causes the circle to vanish with a gesture, freeing the angel.

8.23 Sacrifice

Abaddon is doused with holy oil and set aflame by Sam, forcing her to abandon her meatsuit.

9.01 I Think I'm Gonna Like It Here

Ezekiel is trapped in a circle of holy oil by Dean, after coming to Dean's aide and passes out, allowing Dean to trap him to size him up on his intentions.]]

9.18 Meta Fiction

Sam and Dean lure Gadreel, trapping him in a ring of holy fire.

9.18 Meta Fiction

Metatron plays along with Sam and Dean, allowing himself to be trapped in a ring of holy fire before extinguishing the flames.

9.22 Stairway to Heaven

Sam and Castiel find the angel Josiah badly burned by holy fire. After falling for the trap laid out by Metatron, Josiah was doused with holy oil and set aflame by a flame thrower hanging over the entrance to what he thought was a doorway to Heaven.

10.03 Soul Survivor

In protest to the way that Crowley had been running Hell, a demon douses himself in holy oil and immolates himself in front of Crowley.

10.18 Book of the Damned

When preparing to destroy the Book of the Damned, Dean adds holy oil to the fire. However, Sam only pretends to burn the book.

11.01 Out of the Darkness, Into the Fire

Dean is shown throwing a container of holy oil into his duffel bag when he is getting weapons out of the Impala's trunk.