what dissolves styrofoam

What dissolves Styrofoam?

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Dissolving Styrofoam


Have you ever wondered what Styrofoam is? What does it take to dissolve it, and why does it happen? Is it possible to completely break it down? We are here to answer your question. In the beginning, we would like to start by mentioning the influence the polystyrene (brand name Styrofoam) has on the environment.

Plastic pollution

A couple of weeks ago, the UN Climate Change Conference took place. It is an excellent opportunity to remind you of the role of plastic in the pollution “life-cycle”.

Polystyrene is one of those materials that surround us everywhere. Polystyrene is an inexpensive and hard plastic, and probably only polyethylene is more common in your everyday life.

Things like computers, toothbrushes, hairdryers, TVs, and kitchen appliances are made of polystyrene. Model cars and airplanes are made from polystyrene, as well as many other toys. Also, Styrofoam is used for packaging and insulation, and a lot of parts the inside of your car, like the knobs, keys, and so on.

Styrofoam is also used to make drinking cups and food containers – the hard plastic ones and also the soft foamy ones.

The worst thing is that plastic never breaks down; it just breaks up into smaller pieces. Every piece of plastic that has ever been produced still exists in the world today! The scary fact is that by 2050, there will be more plastics than fish (by weight) in our oceans. Moreover, the food chain is full of plastics – carrying pollutants with them – especially when we use Styrofoam to carry warm and hot food/drink or to heat the food in the microwave. 

We are writing about this just to remind you – our Dear Readers – that in our experiment, we are dissolving Styrofoam, but not breaking it down. In our experiment, we answer the questions:

  • What dissolves Styrofoam?
  • Why does Styrofoam dissolve?

The experiment – how does acetone dissolve Styrofoam?


In the beginning, please take special precautions and use protective glasses, gloves, and clothes to protect your skin.

We are going to use the following items:

  • A glass container
  • Styrofoam (to make it more attractive to children, you can use shaped one: heart, star, square, box etc.)
  • Acetone

Step 1 – Prepare the Styrofoam

Firstly, you might think there is nothing to prepare, but we encourage you to try to paint the Styrofoam in one color – For example, you can paint heart-shaped block with red color. Once dissolved, you will get a nice result.

Step 2 – Pour acetone

Secondly, pour acetone carefully into the glass container. We are using the rather flat glass container, so there is more space for our Styrofoam. As acetone is a very dangerous substance, please control the speed of pouring and protect your eyes and skin. In any case, DO NOT LET your child touch it, drink it. It can smell it from a distance as it is hard to avoid breathing 😉 Try to perform this experiment rather swiftly.

Step 3 – Put the Styrofoam into the acetone

Thirdly, once we have our container prepared, please place the Styrofoam carefully into it. Our reaction starts immediately, and the Styrofoam starts to dissolve from the bottom. After a couple of seconds, it dissolves completely. You probably noticed that it has been “flat out” but did not break down. You are right! Styrofoam lost its structure because the air bubbles are released. Yes, these are the air bubbles trapped into the polymer material that keeps its shape.

Questions and answers

Taking the opportunity, we have gathered the most popular questions and answers related to the “dissolving Styrofoam.” We hope it will be your one-stop-shop in this topic.

What dissolves Styrofoam?

It is more about a physical rather than a chemical reaction. The air in the foam evaporates, and because Styrofoam consists mainly of air, it completely loses its structure. The acetone breaks up the long chain of molecules, and the air goes away, hence the volume shrinks radically. Acetone is a chemical that dissolves Styrofoam. Some types of spray paint, as well as gasoline, will also dissolve Styrofoam.

Will vinegar dissolve Styrofoam?


Is dissolving Styrofoam in acetone possible?

Yes! This is all our experiment is about. During the chemical reaction, the air bubbles are released and physical structure is destroyed.

Is dissolving Styrofoam in gasoline possible?

Yes! And you know what? Sticky, and viscous material, is effectively homemade “napalm.” It can be be made by dissolving pieces of Styrofoam in gasoline or diesel fuel to form a flammable jelly-like substance. Military-grade napalm was initially made using thickening agents, naphthenic acid and palmitic acid, hence the name. A modern version, napalm-B, is now thickened using styrene derivatives. Faster-burning mixtures use more volatile fluids (such as gasoline), while slower-burning forms use fuel oil or a mix of gas and motor oil.

Does Styrofoam dissolve in water?

Depends on the temperature. When hot water is used the molecules of Styrofoam dissolve in water – hence it is harmful to drink hot beverages in plastic cups. Later on, the plastic molecules are accumulated in our body organs.

What will dissolve Styrofoam?

Acetone is a chemical that dissolves Styrofoam. Some types of spray paint, as well as gasoline, will also dissolve Styrofoam.

What is Styrofoam?

Styrofoam is a trade mark of polystyrene. About a few thousand monomers typically comprise a chain of polystyrene, giving a molecular weight of 100,000–400,000. Each carbon of the backbone has tetrahedral geometry, and those carbons that have a phenyl group (benzene ring) attached are stereogenic. Source: Wikipedia


We are curious about what are your opinions about the experiment and your view on plastic pollution. Do you have any ideas about how to reduce using plastic around you? Please leave a comment.

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