YouTubers are battling for the world record of foam with the elephant toothpaste experiment. Here's

• Nick Uhas and David Dobrik stunned the internet with their successful attempt at breaking the world record for largest amount of foam produced via the elephant toothpaste experiment.
• Before their attempt, science YouTubers Mark Rober and ScienceBob did their own record-breaking stunt in Rober's backyard pool, using a different catalyst.
• If you want to replicate their attempt on a smaller scale at home, ScienceBob put together instructions on his website that are cheap and easy to follow.
• Uhas told Insider that the experiment is safe and environmentally friendly, as long as you use the right materials and follow some basic safety precautions.
• Visit Insider's homepage for more stories.

Science YouTubers are engaging in a bit of a "foam arms race" this week with gargantuan versions of the elephant toothpaste experiment.

Nick Uhas and David Dobrik claimed the world record for the most foam produced via the demonstration, which combines hydrogen peroxide, dish soap, food coloring, and potassium iodide to result in a massive volcano of foam.

Before the pair pulled off their successful attempt, YouTubers Mark Rober and ScienceBob did a version with yeast in Rober's backyard swimming pool that overflowed.

If you're inspired and want to make a significantly smaller version of elephant toothpaste at home, you can. ScienceBob put some cheap, easy-to-follow instructions on his website, and the experiment is kid-friendly as long as you follow some basic safety precautions. With the right clean-up, it's environmentally sound, too.

You only need a few materials to make a foam volcano.

To start, you just need to gather a few materials.

To make ScienceBob's at-home version, you'll need: 

• 1/2 cup of liquid hydrogen peroxide
• 10 drops of liquid food coloring
• 1 tablespoon of liquid dish soap
• 1 packet of dry yeast
• A 16-ounce plastic soda or water bottle OR a bucket that size
• A small cup to hold your yeast and at least 3 tablespoons of warm water
• Plastic gloves and safety googles

Optionally, you can also put a plastic tarp down to catch all the foam.

The reaction starts with liquid hydrogen peroxide, and you can use different strengths for more or less foam.

The YouTubers use 20-Volume hydrogen peroxide, which is a 6% solution that's stronger than the kind found in pharmacies or drug stores. It creates more foam than the standard 3% solution, and can be used to lighten hair, so many beauty supply stores carry it.

However, the 6% solution can irritate skin and eyes, so if you're using it, you should wear gloves and safety goggles. You also wouldn't want to touch the foam afterward, because there may be un-reacted peroxide in it. If you use the 3% solution found in pharmacies, you can touch the foam afterward.

ScienceBob's instructions call for 1/2 cup of hydrogen peroxide, and he recommends using a 16-ounce plastic soda bottle or water bottle to mix the solution at home. A container with a funneled top makes the foam shoot out in a steady stream, whereas a container like a bucket causes it to spill over the sides.

If using a funneled top, you should definitely do the experiment outside, because the stream can reach several feet in the air.

Either way, it's a good idea to do the experiment outside, since it involves so much spillover. But if you want to do it inside, be sure to line the area with plastic.

Add food coloring and dish soap to the hydrogen peroxide mixture to create colored foam.

ScienceBob suggests 10 drops of food coloring and about 1 tablespoon of liquid dish soap to make the foam colorful. You can also do the demonstration without dish soap, and the reaction will still take place, but it won't create the bubbly foam.

You should swish the ingredients around in the container to create a mixture.

If you use dye, it can stain ceilings to the point where it's almost impossible to clean. Uhas told Insider that he tried the experiment inside Dobrik's house, and the stained ceiling now rejects new coats of paint because the iodide seeps through.

In a separate cup, combine dry yeast and warm water for the at-home catalyst, instead of the potassium iodide that Uhas used.

The potassium iodide in Uhas and Dobrik's experiment is a more powerful catalyst that produces an explosion effect, as opposed to the rising foam that filled Rober's pool. Uhas told Insider that the iodide isn't toxic, and is actually edible, but it's used for medical purposes and is more expensive than yeast.

ScienceBob recommends using a tablespoon of dry yeast, or one packet. He combines it with three or more tablespoons of warm water in a separate small container, and mixes it for about 30 seconds, until the mixture has the consistency of "melted ice cream." You can add more water to reach that consistency.

Uhas and Rober used huge contraptions that required multiple people to pour the catalyst into the peroxide, but you can just use a funnel at home.

As both videos exhibited, all you need to do to jump-start the chemical reaction is combine the catalyst with the peroxide mixture. That means you can just use a funnel or pour the dissolved yeast into the hydrogen peroxide.

The reaction starts almost immediately, so step back or point the container away from yourself to avoid getting splashed with foam. Another important thing to note is that the reaction is exothermic, meaning that the foam will be hot.

You should be mindful not to hold on to the container where the reaction is taking place unless you're wearing gloves or another covering that will shield you from heat. You also shouldn't touch the foam right away, but you can touch it if you used a 3% solution after it's cooled down.

Uhas told Insider that the foam is "self-cleaning."

After the reaction concludes, you're left with a lot of soapy foam. If you use potassium iodide as the catalyst, Uhas told Insider that it becomes iodine, which leaves a powerful stain – another reason to do the elephant toothpaste experiment outside and away from your house or any sort of concrete or plaster.

If you're using the yeast, it shouldn't stain as badly, but you should still exhibit caution. Fortunately, the foam is just water, soap, and oxygen, and will release oxygen on its own until you're left with soapy, colored water.

You can sop that up and recycle the plastic you put down, like Uhas and Dobrik did. The remaining liquid is also drain-safe. If you have enough materials on hand, you can try different variations of the experiment like Rober did in his video — or see how much foam you can produce by increasing the quantity of materials.

See the full instructions from ScienceBob here »

Have fun!

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