When Jedi Master Qui-Gon Jinn and his Padawan Obi-Wan Kenobi were sent by Supreme Chancellor Valorum to negotiate the blockade of Naboo, the ambassadors were double-crossed by Nute Gunray. The Neimoidians released dioxis gas via gas emitters into the Saak'ak's conference room where the Jedi waited. However, their command of the Force afforded them a sense of the danger, and were able to survive in the toxic environment until a squad of security battle droids arrived with orders to dispose of their bodies.
Thirteen years later, on Cato Neimoidia, Obi-Wan Kenobi identified a toxic gas released by Nute Gunray's mechno-chair as dioxis—though this toxin was also identified as swamp gas, the chemical weapon used by the Separatists on Ohma-D'un earlier in the Clone Wars.
Around 21 BBY, dioxis was used as part of a contest arranged by Count Dooku on his homeworld of Serenno. Within a construct known as The Box, eleven bounty hunters competed in a series of tasks to prove their worthiness to be part of a team that would abduct Supreme Chancellor Palpatine on Naboo. The first task involved the competitors having to escape a room that was filling with dioxis gas.
- Star Wars: Obi-Wan
- Star Wars Episode I: The Phantom Menace novel (First appearance)
- Star Wars: Episode I The Phantom Menace
- Star Wars Episode I: The Phantom Menace comic (as "gas")
- Star Wars Episode I: The Phantom Menace junior novel
- Star Wars Episode I: The Phantom Menace game
- Star Wars Episode I: Jedi Power Battles
- Star Wars: The Clone Wars – "The Box"
- Labyrinth of Evil
- Star Wars Galaxies: An Empire Divided
- Star Wars: Episode I The Visual Dictionary
- Star Wars Customizable Card Game – Coruscant Limited (Card: Dioxis)
- The Official Star Wars Fact File 13 (JIN3, Qui-Gon Jinn)
- The New Essential Chronology
- Star Wars Galaxies Trading Card Game – Champions of the Force (Card: Dioxis Gas)
- Star Wars Galaxies Trading Card Game – Galactic Hunters (Card: Dioxis Grenade)
- The Complete Star Wars Encyclopedia
- Galaxy at War
- The Bounty Hunter Code: From the Files of Boba Fett
- Lords of Nal Hutta