Promethium
"Promethium is the heartblood of the Imperium, pulsing through its great engines of war and commerce, expanding Mankind's realm with the regularity of a drum. And when it is spilled, it burns away all the impure with the heat of our hatred."
Promethium is a broad term for any form of combustible fuel in the Imperium.[6]
The term also commonly refers to the substance used as fuel for Imperial flamer weapons, a highly volatile incendiary gel which immediately ignites on contact with oxygen. It reaches super hot temperatures. Similar to napalm, the gel sticks to an individual, continuing to burn on its own accord, even underwater and in space.[1] It also fuels most spacecraft and vehicles, both military and civilian.[1]
In addition to this, Promethium is used to create an array of everyday necessities, ranging from dyes and plastics to pharmaceuticals and synthetic protein bars.[2]
Promethium is extracted and refined in a number of different ways. Some of the most common methods are extracting it from the atmospheres of gas giants, the mining of ancient organic material deposits, the processing of certain rare ices that are only found on ice worlds, or from beneath a world's seabed thanks to Promethium Rigs.[2][3] The Imperium stores the fuel in Promethium Barrels for later use or so that it can be transported elsewhere.[5]
Sources
- 1: Codex: Imperial Guard (3rd Edition, 2nd Codex), pg. 62
- 2: Caves of Ice (Novel) — Ciaphas Cain: Hero of the Imperium (Omnibus), Editorial Note after Chapter Two, pgs. 317–318
- 3: Kill Team: Salvation, pg. 5 - The Gallowdark's End
- 4: Warhammer 40,000: Space Marine 2, Inferno loading screen
- 5: Warhammer: Battlezone: Manufactorum – Munitorum Armoured Containers (archived from the original, last accessed 25 September 2025)
- 6: Warhammer 40,000: Rogue Trader (Video Game), Dictionary
