What is inside a Glow Stick? #Chemiluminescence #Chemistry #HalloweenScience Inside a glow stick, there's a chemical reaction that produces light without heat, known as chemiluminescence. The glow stick consists of a plastic tube containing a hydrogen peroxide solution and a glass vial inside it that holds a phenyl oxalate ester and a fluorescent dye. When the stick is bent, the glass vial breaks, allowing the two solutions to mix. The hydrogen peroxide reacts with the phenyl oxalate ester, prod