Mustard Gas Neutralizing Agent, Batman Wiki
A capsule of chemicals was kept on Batman's Utility Belt in his early career. The contents were capable of mixing with mustard gas and rendering the agent harmless. Batman made use of the vial to escape a trap set up by Sheldon Lenox in Sin Fang's Shop. Detective Comics #35: "The Case of the Ruby Idol" Though the capsule's contents are never specified, it's possible the agent was hydrogen peroxide.
Mustard gas - Wikipedia
Marvel: 25 Weird Facts Only Super Fans Knew About Captain America's Body
Cian Beirdd Telling the stories of the millennia one character at a time
The Sheep Incident • Damn Interesting
Chemical Weapon - Zarco Macross
Chemical weapon - Wikipedia
Chemical Weapon - Zarco Macross
Lewisite, C2H2AsCl3
Can xenomorphs moleluclar acid eat through a space marines armour? - Quora
Scarecrow's Fear Toxin, DC Database
Historical Perspective of Chemical Warfare Agents - ScienceDirect
Ratcatcher (disambiguation), DC Database
Ace Chemical Processing Plant, Batman Wiki
Mustard Gas Neutralizing Agent, Batman Wiki
Fear Toxin, Arkham Wiki