Holy Oil

"When the oil burns, no angel can touch or pass through the flames, or he dies."

- Castiel

Holy Oil is a very rare substance that can be found in Jerusalem. A circle of burning holy oil is so far the only way to trap a celestial being. Utilized properly, it is also one of the few substances that can kill all angels but Michael. It also has a level of effectiveness against demons, killing lower demons and causing severe pain to higher demons. It can work as a cure for Rabids. It is part of the ritual to create new bullets for the Colt and the ritual to seal a rift in space and time.

Characteristics
The angel will not be able to leave the circle, or both it and its vessel will face certain death. It should be noted that a circle of holy fire is not the equivalent of a devil's trap: while inside the circle, the angel can still use of some of their abilities and are able to move; they merely choose not to leave the circle out of fear of touching or passing through the holy fire. If an angel touches or passes through/over holy fire, then not only will the human vessel be destroyed and die, the angel will be killed as well. However, if an angel is burned by holy fire merely to the brink of death and doesn't die right away, another angel can heal them of their injuries.

Michael, however, is resistant to the holy fire and could not be killed by it. The Holy Fire is still extremely painful for him and can temporarily banish him. Holy Fire is capable of holding at least Gabriel and Raphael, though the latter somehow escapes without being released. It was also recently shown to be capable of holding Lucifer for a short time.

Holy Fire can kill demons if they are in it long enough, otherwise it will just cause them extreme pain, as demonstrated in Abandon All Hope..., when Castiel threw Meg into Holy Fire.

Sam later uses it in Sacrifice to burn Abaddon when she attacks him and Crowley. She quickly abandons her vessel Josie Sands and flees the scene.

In Soul Survivor, a demon dissatisfied with Crowley's rule douses himself in Holy Oil and ignites it, killing himself.

According to the demon Word of God tablet, Hellhounds can be seen through an object scorched with Holy Fire. This is shown to be true in Trial and Error when Dean scorches two pairs of glasses with Holy Fire and he and Sam are able to see and kill a Hellhound.

When he was searching for a cure for rabids, Sam found a reference in the Bible to holy oil being used for purifications. Having learned that he is "unclean in a biblical sense", Sam used a sponge doused in holy fire on himself and the rabid infection burned away. Mere proximity to holy fire was also proven to be enough to cure rabids, as a group was cured when Sam trapped them in a ring of holy fire.

Crowley later states that even when combined with warding, holy fire can only contain an archangel for a few minutes. However, as it was shown to easily hold both Raphael and Gabriel, this may be in relation to Lucifer who is more powerful than the other two.

In an attempt to free Castiel from Lucifer's possession and send him back to the Cage, the Winchesters, Crowley and Rowena summoned Lucifer into an angel trap surrounded by holy fire. Eventually the warding and the holy fire failed and Lucifer was released.

While battling the Prince of Hell Ramiel, Sam, Dean and Mary Winchester used a circle of holy fire to contain him. Ramiel simply commented that it was "toasty" and broke free easily minutes later using the Lance of Michael.

After discovering that the British Men of Letters possess the Colt, Sam tells Mick Davies that he will need to create a tincture of holy oil, sage and myrrh as part of the ritual to create new bullets for the Colt.

Holy oil was one of the ingredients used by Crowley and Sam in the ritual to seal a rift into an apocalyptic alternate reality.

Angels

 * Castiel
 * Raphael
 * Michael
 * Gabriel
 * Balthazar
 * Gadreel
 * Metatron
 * Josiah
 * Lucifer

Demons

 * Meg
 * Abaddon
 * Suicidal Demon
 * Ramiel

Rabids

 * Sam Winchester
 * Population of Superior, Nebraska

Appearances

 * Season 5
 * Free To Be You And Me  (First appearance, used to trap Raphael)
 * Changing Channels (Used to trap Gabriel)
 * Abandon All Hope...  (Used to trap Castiel, Meg thrown into but just burned)
 * Swan Song  (Used to banish Michael)
 * Season 6
 * The Third Man  (Used to trap Balthazar)
 * The Man Who Would Be King  (Used to trap Castiel)
 * Season 8
 * Trial and Error  (Used to burn glasses, so they could see Hellhounds)
 * Sacrifice (Used on Abaddon, as a higher demon it didn't kill her but forced her to flee)
 * Season 9
 * I Think I'm Gonna Like It Here (Used to trap Gadreel)
 * Meta Fiction (Used to trap Gadreel and Metatron)
 * Stairway To Heaven (Used by Metatron to kill Josiah)
 * Season 10
 * Soul Survivor (Used by an unnamed demon to commit suicide)
 * Season 11
 * Form and Void (Used by Sam to cure himself and rabids in Superior, Nebraska)
 * Hell's Angel (Used by the Winchesters, Rowena and Crowley to contain Lucifer)
 * Season 12
 * Stuck in the Middle (With You) (Used by the Winchesters to trap Ramiel)
 * The Raid (Used by Mick Davies to create new bullets for the Colt)
 * All Along the Watchtower (Used by Sam Winchester and Crowley to seal a rift in space and time)