What Is Styrofoam?


There’s Only One Styrofoam™ (and it’s not a cup)

When people hear the word “Styrofoam,” they often think of foam cups, fast food containers or packaging. But construction professionals know better. Unlike the expanded polystyrene (EPS) foam that’s used to make disposable containers, DuPont™ Styrofoam™ Brand Extruded Polystyrene (XPS) Insulation is a high-performance, closed cell foam used to insulate homes and buildings. That closed cell structure is what gives Styrofoam™ Brand the thermal protection and moisture resistance that help buildings stay warm in the winter, cool in the summer and dry year-round.

What is ‘closed cell’ foam? If you look at the white EPS foam you know as disposable cups, coolers and packaging under a microscope, you’ll see gaps between the foam cells. Over time, those gaps let in air and moisture. Those gaps also reduce the material’s compression strength. Ever crushed a foam cup in your hand? That’s low compression strength! However, if you look at Styrofoam™ Brand XPS Insulation under a microscope, you won’t see those gaps. It’s a closed cell foam that provides exceptional thermal, moisture and air protection for homes and buildings. It also has great compression strength, so it can withstand the demands of a tough jobsite, last for decades and even be reused when buildings are remodeled!

Now that you know there’s only one Styrofoam™ Brand  and it’s not a cup – what should you call those white foam cups, containers, coolers and packages? EPS, polystyrene or foam are all accurate terms to describe EPS material. Styrofoam™ is an entirely different material – a rigid board insulation invented in 1941, trademarked, and known for it’s distinctive blue or grey color.

Frequently Asked Questions 

If Styrofoam™ Brand is not a cup, what is it?

Styrofoam™ Brand XPS is an extruded polystyrene (XPS), rigid board insulation used to provide thermal, moisture and air protection in homes, buildings, insulated trucks, roofs, highways, tunnels, insulated pipes and other places of shelter and infrastructure that are designed to last decades.

What about those white foam cups and coolers that people refer to as Styrofoam™?

They don’t exist. In fact, there isn’t a cup, food container, cooler or packaging material in the world made from Styrofoam™ Brand material. Those items are made from a type of expanded polystyrene (EPS) that doesn’t have the insulation value, moisture resistance or compression strength of Styrofoam™ Brand.

Why does it matter?

We can think of two good reasons. Number one in our book is protection of a product that we think is pretty great – Styrofoam™ Brand XPS Insulation. It’s trademarked and an entirely different material than the expanded polystyrene (EPS) foam used to make one-time use containers. Secondly, it’s a way to place an easy bet at parties. Bet your friends they can’t find a Styrofoam™ cup. They won’t, because it doesn’t exist!

How do I know if it’s the real Styrofoam™ Brand?

Simply look for the genuine Styrofoam™ Brand trademark! DuPont holds more than 150 trademark registrations worldwide for the Styrofoam™ Brand.