With no bulb or battery, glow sticks manage to give off a strong light. So how exactly do glow sticks work? Glow stick light is the result of a chemical reaction. Most glow sticks hold a hydrogen peroxide solution and a solution containing phenyl oxalate ester and a fluorescent dye. When the two compounds are mixed, the hydrogen peroxide oxidizes the phenyl oxalate ester, resulting in a chemical called phenol and an unstable acid ester. The unstable compound decomposes, resulting in additional phenol and a cyclic peroxy compound. The cyclic peroxy compound then decomposes to carbon dioxide; this decomposition process releases energy to the dye, and the electrons in the dye atoms jump to a higher level, then fall back down, releasing energy in the form of light.

The actual light stick is simply a form of housing the two solutions. In the stick, the two solutions are kept in separate chambers. The phenyl oxalate ester and dye solution fills most of the glow stick, while the hydrogen peroxide solution is held in a smaller glass vial within the middle of the stick. This is why glow sticks must be bent to activate - bending the plastic stick breaks the glass vial open, allowing the two solutions to mix.

The glow stick can stay lit for hours, if enough compounds are used. However, more commercial glow sticks are likely to last up to 30 minutes. Also, heating the glow stick will cause it to glow brighter, but it will also dim more quickly. Similarly, cooling the stick will slow down the process and cause a dimmer light to last much longer. Freezing a glow stick can cause the light to last for several days, though it will eventually fade out.

Although some websites offer information on how to make a glow stick, this is discouraged unless a person has a background in science and considerable training in chemical compounds. While relatively safe, mixing the compounds incorrectly can lead to inadvertent results, and the dye can harm clothing and other fabrics.