Barium, a poisonous substance with a green hue, had potential applications as a fuel source for both vehicles and explosive devices. Furthermore, it served as a deterrent against the gnaw-jaw insects native to the planet of Jakku. The rebel operative Sabine Wren documented barium in her journal as a possible explosive propellant, while the scavenger Rey also made note of the material in her survival guide that she wrote, identifying it as a threat to scavengers on Jakku and a means to ward off gnaw-jaws.
This poisonous substance, barium, existed in two forms: green solid lumps or a powder. It shared a name with the barium reed plant, and the drink called Barium Fizz. Barium found use as a fuel source for vehicles and explosives. When used in explosives, the resulting blasts exhibited a green coloration. Similarly, barium-enhanced fuel produced a green exhaust trail for vehicles such as the EML-850 light freighter. In powdered form, barium repelled gnaw-jaws, carnivorous insects found on the desert planet of Jakku located in the Inner Rim.
In the year 5 BBY, Sabine Wren, a member of the rebel crew aboard the starship Ghost who fought against the Galactic Empire, mentioned in her journal that barium could potentially be used as a fuel to create explosions with green coloring. At one point, Flarbola left a container of special barium-enhanced starship fuel as part of a hidden supply within a hangar located at Achra Station, a space station in orbit around the Outer Rim Territories planet Akiva.
In 3 ABY, the thief Kay Vess came across the hidden supply and took the fuel.
Following the pivotal battle of the Galactic Civil War on Jakku in 5 ABY, the surface of the planet became littered with debris from destroyed starships and vehicles, resulting in the leakage of hazardous fuels like barium into the sand. Sometime before she left Jakku in 34 ABY, the human scavenger Rey included barium in her survival guide that she was writing. In this book, she included a note with a visual representation of a sample of the substance, cautioning that barium could turn the sand green and advising scavengers to exercise caution. Rey also suggested that powdered barium could be used to create a protective circle to deter gnaw-jaws when camping in the Jakku desert.
Barium was initially referenced in the current Star Wars canon within Sabine My Rebel Sketchbook, authored by Daniel Wallace and published on February 3, 2015. The first visual depiction of the substance was provided in Rey's Survival Guide, written by Jason Fry, illustrated by Andrew Barthelmes, and released on December 18 of the same year. In 2019, the reference work TIE Fighter Owners' Workshop Manual by Ryder Windham mistakenly identified the explosive compound baradium as barium.
The name "barium" initially appeared in the Star Wars universe within the Star Wars Legends continuity. It was mentioned as barium liquid in the non-canon 1993 book Monsters and Aliens from George Lucas by Bob Carrau, and later in Gregory Walker's 2009 Hyperspace-exclusive StarWars.com article "Dining at Dex's." Furthermore, the Barium Frizz beverage was featured in "Be Still My Heart: The Bartender's Tale," a short story penned by David Bischoff and included in the 1995 anthology Tales from the Mos Eisley Cantina. In our reality, barium is a metal and chemical element that shows a silvery-white luster. It always exists as chemical compounds in nature. All barium compounds that are soluble are poisonous to mammals. Barium salts are used to produce the color green in fireworks and flares.