Kid-Friendly Elephant Toothpaste Demo

Safe Way to Make Foamy Elephant Toothpaste

Mixing yeast and peroxide with detergent produces foam similar to shaving cream. It can be used to make a chemical volcano or as a kid-friendly elephant toothpaste demo.
Mixing yeast and peroxide with detergent produces foam similar to shaving cream. It can be used to make a chemical volcano or as a kid-friendly elephant toothpaste demo. SCIENCE PHOTO LIBRARY / Getty Images

The elephant toothpaste demo is one of the most popular chemistry demos, in which a steaming tube of foam keeps erupting from its container, resembling a smooshed tube of elephant-sized toothpaste. The classic demo uses 30% hydrogen peroxide, which is not safe for kids, but there is a safe version of this demonstration that is still very cool.

Elephant Toothpaste Materials

  • empty 20-oz plastic bottle (or other container)
  • 3% hydrogen peroxide solution (available at nearly any store)
  • packet of active yeast (from the grocery store)
  • liquid dishwashing detergent (such as Dawn™)
  • warm water
  • food coloring (optional, but it looks nice)

Make Elephant Toothpaste

  1. Pour 1/2 cup hydrogen peroxide solution, 1/4 cup dishwashing soap, and a few drops of food coloring into the bottle. Swish the bottle around to mix the ingredients. Set the bottle in a sink or outdoors or some other place where you won't mind getting wet foam everywhere.
  2. In a separate container, mix a packet of active yeast with a little warm water. Give the yeast about 5 minutes to activate before proceeding to the next step.
  3. When you are ready to do the demo, pour the yeast mixture into the bottle.

How It Works

Hydrogen peroxide (H2O2) is a reactive molecule that readily decomposes into water (H2O) and oxygen:

2H2O2 → 2H2O + O2(g)

In this demonstration, yeast catalyzes the decomposition so that it proceeds much more rapidly than normal.

Yeast need warm water in order to reproduce, so the reaction won't work as well if you use cold water (no reaction) or very hot water (which kills the yeast). The dishwashing detergent captures the oxygen that is released, making foam. Food coloring can color the film of the bubbles so that you get colored foam.

In addition to being a nice example of a decomposition reaction and a catalyzed reaction, the elephant toothpaste demo is exothermic, so heat is produced. However, the reaction just makes the solution warmer, not hot enough to cause burns.

Christmas Tree Elephant Toothpaste

You can easily use the elephant toothpaste reaction as a holiday chemistry demonstration. All you need to do is add green food coloring to the peroxide and detergent mixture and then pour the two solutions into a Christmas tree-shaped container. A good choice is an erlenmeyer flask. If you don't have access to chemistry glassware, you can make a tree shape by inverting a funnel over a glass or making your own funnel using paper and tape (which you could decorate, if you like).

Comparing the Original Reaction With the Kid-Friendly Recipe

The original elephant toothpaste reaction, which uses a much higher concentration of hydrogen peroxide, can cause both chemical burns and thermal burns. While it produces a larger amount of foam, it's not safe for kids and should only be performed by an adult using proper safety gear. From a chemistry perspective, both reactions are similar, except the kid-safe version is catalyzed by yeast, while the original demonstration is usually catalyzed using potassium iodide (KI).

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Your Citation
Helmenstine, Anne Marie, Ph.D. "Kid-Friendly Elephant Toothpaste Demo." ThoughtCo, Dec. 5, 2016, thoughtco.com/kid-friendly-elephant-toothpaste-demo-604164. Helmenstine, Anne Marie, Ph.D. (2016, December 5). Kid-Friendly Elephant Toothpaste Demo. Retrieved from https://www.thoughtco.com/kid-friendly-elephant-toothpaste-demo-604164 Helmenstine, Anne Marie, Ph.D. "Kid-Friendly Elephant Toothpaste Demo." ThoughtCo. https://www.thoughtco.com/kid-friendly-elephant-toothpaste-demo-604164 (accessed September 22, 2017).