What chemicals are inside a glow stick?

A glow stick contains two separated solutions: an oxalate ester like phenyl oxalate ester plus a fluorescent dye, and an activator solution of hydrogen peroxide in a solvent such as dimethyl phthalate. When the inner glass vial breaks and the solutions mix, a chemical reaction produces light.

Is hydrogen peroxide in glow sticks dangerous?

The hydrogen peroxide in a glow stick is diluted and sealed inside the plastic tube, so it is not dangerous when the stick is intact. If the stick breaks, avoid skin and eye contact and do not swallow the liquid, since the chemicals can irritate or be toxic.

What makes a glow stick glow different colors?

The color comes from the fluorescent dye mixed with the oxalate ester, not from the reaction itself. Different dyes absorb the reaction's energy and re-emit it at specific wavelengths, producing colors like green, blue, pink, or yellow.

Why does a glow stick stop glowing?

A glow stick fades when the hydrogen peroxide or oxalate ester is used up, so the light-producing reaction can no longer continue. Once the chemicals are consumed, the stick stays dark and cannot be reactivated by shaking.

Are glow sticks toxic if swallowed?

Yes, the liquid inside can be toxic or irritating if swallowed, and it can cause nausea, vomiting, or burning in the mouth and throat. If someone swallows glow stick liquid, call poison control or seek medical help right away.

What Chemicals Are in Glow Sticks: Inside Chemiluminescence

Most glow sticks contain two liquids kept separate until the stick is bent. One contains hydrogen peroxide. The other contains a phenyl oxalate ester, such as diphenyl oxalate, and a fluorescent dye. A solvent or plasticizer helps keep ingredients dissolved.

When the inner glass vial breaks, the liquids mix and start a chemical reaction that produces light. The exact ingredients vary by product, but the basic recipe is hydrogen peroxide, an oxalate ester, a dye and supporting liquid ingredients.

The main ingredients

Hydrogen peroxide (H₂O₂) is in one compartment. It reacts with the oxalate ester after the liquids mix. PubChem: Hydrogen Peroxide

A phenyl oxalate ester, often diphenyl oxalate, is in the other compartment with the dye. It reacts with hydrogen peroxide and helps generate the energy that the dye releases as light. PubChem: Phenyl Oxalate Esters

A fluorescent dye determines the light’s color. Different dyes emit different colors when energized.

A solvent or plasticizer keeps ingredients dissolved and able to mix. The specific supporting chemicals can vary by formulation.

How the chemicals make light

Bending a glow stick breaks the small glass vial inside its plastic casing. The liquids mix, and hydrogen peroxide reacts with the oxalate ester. The reaction forms an unstable, high-energy intermediate, which transfers energy to the dye. The dye’s electrons enter an excited state, then release energy as visible light as they return to a lower-energy state.

This process is called chemiluminescence: light produced by a chemical reaction. Encyclopaedia Britannica: Chemiluminescence The American Chemical Society describes the glow-stick reaction as energy passing from the chemical reaction to the dye, which emits light. American Chemical Society: Chemistry of Glow Sticks

The dye changes the color; it does not supply the main reactants. A green glow stick and a red one can use the same general peroxide-and-ester chemistry while producing different colors because they contain different dyes.

One example: a green glow stick

In a typical green glow stick, hydrogen peroxide reacts with an oxalate ester, and the resulting energy excites a green-emitting dye. The dye releases that energy as green light. The exact dye and supporting ingredients depend on the product, so the color alone does not identify a specific chemical.

Why the glow fades

The light fades as the reaction proceeds and the reactive ingredients are used up. Once the reaction no longer produces enough energy to excite the dye, the glow weakens and eventually stops. Liquid may remain inside the stick, but it can consist largely of spent reaction products and other ingredients.

Temperature affects how quickly the reaction proceeds. Warmth can make a stick glow more brightly for a time, then fade sooner. Cold can slow the reaction and leave a dimmer glow for longer. The ingredients and conditions differ across products, so the timing and brightness vary.

Why glow sticks stay relatively cool

Glow sticks produce light through a chemical reaction, not by burning fuel or heating a filament. They can warm slightly, but the light does not come from heat in the way it does with a flame or incandescent bulb. The reaction transfers energy to the dye, which releases some of it as photons.

What to know about handling

Glow sticks are sealed to keep their liquids contained. Do not cut or puncture one. If a stick breaks and liquid contacts skin, rinse the area with water. Follow the product’s label for cleanup and safety instructions, and keep the contents away from eyes and mouth.

Key Takeaways

Glow sticks generally contain hydrogen peroxide in one compartment and a phenyl oxalate ester with fluorescent dye in another.
A solvent or plasticizer helps keep the ingredients dissolved.
Bending the stick breaks its inner vial and starts a reaction that transfers energy to the dye, producing light.
The dye determines the color. The glow fades as the reaction’s usable ingredients are consumed.
Keep the liquids contained and follow the product label if a glow stick breaks.

What Chemicals Are in Glow Sticks and How They Produce Light