Glow sticks fascinate with their vibrant, temporary light. Despite their bright appearance, glow sticks do not contain neon. Their illumination stems from a distinct chemical process, unlike the electrical excitation that powers true neon signs.
Understanding Neon
Neon is a chemical element, classified as a noble gas, found naturally in trace amounts within Earth’s atmosphere. Like other noble gases, pure neon is a colorless, odorless, and inert gas under normal conditions. It does not readily react with other elements due to its stable atomic structure.
The element’s most recognized application is in “neon signs.” An electric current passes through a sealed glass tube filled with neon gas, exciting its atoms. This excitation causes the neon atoms to release energy as a characteristic bright reddish-orange glow. While many colorful signs are broadly called “neon,” tubes with other gases or fluorescent coatings produce different hues, such as argon for blue or purple.
The True Chemistry of Glow Sticks
Glow sticks operate on the principle of chemiluminescence, a chemical reaction that produces light with minimal heat. This “cold light” phenomenon is distinct from incandescence, which generates light through high temperatures. The light from a glow stick is the direct result of energy released during molecular transformations.
Inside a typical glow stick, two chemical solutions are separated. One solution, filling most of the plastic tube, contains a fluorescent dye and an oxalate ester. The other solution, usually hydrogen peroxide, is sealed within a small, brittle glass vial inside the main tube.
Activating a glow stick involves bending it, which breaks the inner glass vial, allowing the hydrogen peroxide to mix with the oxalate ester and fluorescent dye. The hydrogen peroxide oxidizes the oxalate ester, producing an unstable intermediate compound. This compound decomposes, releasing energy. The fluorescent dye molecules absorb this energy, exciting their electrons to a higher level. As these excited electrons return to their original state, they emit the energy as visible light, with the specific color determined by the dye used.
Dispelling the Myth and Glow Stick Safety
The widespread misconception that glow sticks contain neon likely arises from the common use of the word “neon” to describe anything brightly colored or artificially glowing. This association has extended beyond true neon gas signs to various light-emitting products, including glow sticks. However, the underlying science for each is different.
While glow stick chemicals are non-toxic, direct contact should be avoided. The liquid inside can cause mild irritation if it touches skin or eyes, and ingestion may lead to an upset stomach or mouth irritation. If a glow stick breaks, wash any affected skin or flush eyes with water immediately. Advise supervision when children use glow sticks to prevent them from biting or breaking the plastic casing. Used glow sticks should be disposed of in regular trash, as they are not recyclable due to their mixed material composition and chemical contents.