In a world where packaging and insulation materials play an essential role in our daily lives, two terms often pop up in the conversation: Styrofoam and Polystyrene.

You’ve probably encountered them countless times, whether you realize it or not. But do you know the real differences between these two materials, and more importantly, are you aware of their impact on the environment?

Our journey today takes us into the realm of Styrofoam and Polystyrene, delving deep into their characteristics, applications, and their widespread use. Our guiding light behind this exploration is to provide you with an educational, engaging, and informative comparison—not a promotional pitch for either material.

So, let’s embark on this journey of discovery, armed with facts and insights, to understand the intricate dynamics of Styrofoam and Polystyrene.

So, fasten your seatbelts as we navigate the Styrofoam vs. Polystyrene terrain, revealing the distinctions. By the end of this journey, you’ll be better equipped to make informed decisions about the materials you encounter in your everyday life.

What is Styrofoam?

Styrofoam, a term often used colloquially, is a lightweight and versatile material known for its excellent insulating properties. It’s commonly recognized by its distinct blue or white appearance, with a foamy and slightly porous texture.

However, there’s a crucial point of clarification: Styrofoam is actually a trademarked brand name for a type of expanded polystyrene foam (EPS) created by Dow Chemical Company.

When we refer to Styrofoam in this context, we’re talking about EPS foam.

EPS foam is composed of tiny polystyrene beads that are expanded and molded into various shapes to create products like cups, plates, packaging materials, and insulation boards. This material is prized for its lightweight nature, which makes it ideal for insulation purposes, as well as for its cost-effectiveness in manufacturing.

Common Uses of Styrofoam

Styrofoam’s insulating properties and affordability have led to its widespread use in various industries and everyday applications. Here are some common uses:

– Food Packaging: You’ll often find Styrofoam containers and cups used for takeout food and beverages due to their insulation capabilities, which help keep hot items hot and cold items cold.

– Construction and Insulation: EPS foam boards are employed as insulation materials in buildings. They offer excellent thermal resistance and are easy to install.

– Arts and Crafts: The lightweight and easy-to-cut nature of Styrofoam makes it a popular choice for DIY projects, crafts, and model building.

– Shipping and Packaging: It’s frequently used as protective packaging material to safeguard fragile items during shipping.

– Floatation Devices: Some water sports equipment and floatation devices utilize Styrofoam for buoyancy.

What is Polystyrene?

Polystyrene, like Styrofoam, is a widely used plastic material known for its lightweight and durable properties. It’s a synthetic polymer made from the monomer styrene and is commonly found in two main forms: solid and foam.

Solid Polystyrene (PS):

Solid PS is rigid and transparent, resembling glass. It is used in a variety of consumer and industrial applications. Some key characteristics of solid PS include:

– Clarity: It has excellent clarity and can be easily molded into different shapes.

– Brittle: Solid PS is relatively brittle, making it less flexible compared to other plastics.

– Applications: Solid PS is used in products like disposable cutlery, CD cases, and optical lenses due to its clarity and ease of manufacturing.

Polystyrene Foam

Polystyrene foam, also known as expanded polystyrene (EPS) foam, is what most people associate with the term “Polystyrene.” It’s a lightweight, white, and typically rigid material, similar in appearance to Styrofoam. Key features of Polystyrene foam include:

– Insulation: EPS foam is an excellent insulator, making it valuable in the construction industry for insulating walls, roofs, and foundations.

– Lightweight: It’s extremely lightweight, which contributes to its popularity in packaging and insulating applications.

– Shock Absorption: Polystyrene foam can absorb shocks and vibrations, making it useful for protecting delicate items during shipping.

– Buoyancy: It’s often used in floatation devices and boating equipment due to its buoyant properties.

Common Uses of Polystyrene

Polystyrene, in its foam form, has a range of applications, including:

– Packaging: It’s widely used in packaging materials like foam packaging peanuts, cushioning for fragile items, and protective packaging for electronics.

– Construction: Polystyrene foam boards are used for insulation in buildings to improve energy efficiency.

– Food Service: Foam containers and cups are used for takeout food and beverages due to their insulation properties.

– Hobbies and Crafts: Polystyrene foam is a popular choice for model building and crafting.

Key Differences Between Styrofoam and Polystyrene

While Styrofoam and Polystyrene (specifically, EPS foam) share similarities in appearance and are both made from polystyrene, they have significant differences in terms of properties, applications, and environmental impact.

Understanding these distinctions is essential for making informed choices. Let’s explore the key differences:

a. Physical Properties:

– Density: Styrofoam (EPS foam) is less dense than solid Polystyrene. This lower density contributes to its lightweight and buoyant characteristics.
– Rigidity: EPS foam is often more rigid, making it suitable for insulation and packaging. Solid Polystyrene, on the other hand, is rigid but can be brittle.
– Appearance: Both materials are typically white and have a foamy texture, but solid Polystyrene can also be transparent.

b. Insulation Capability:

– Styrofoam (EPS Foam): It excels as an insulator due to its low thermal conductivity. This makes it a top choice for insulating buildings and packaging materials.
– Solid Polystyrene: While it offers some insulating properties, it is not as effective as EPS foam in this regard.

c. Durability:

– Styrofoam (EPS Foam): It is durable and resistant to moisture, making it suitable for long-term use in various applications.
– Solid Polystyrene: Solid PS can be less durable due to its brittleness, especially in comparison to EPS foam.

d. Cost:

– Styrofoam (EPS Foam): Generally, EPS foam is cost-effective to manufacture and is widely used in affordable packaging and insulation solutions.
– Solid Polystyrene: Solid PS can be costlier to produce, which can affect the pricing of products that use it.

e. Applications:

– Styrofoam (EPS Foam): EPS foam is commonly used in packaging, insulation, and floatation devices due to its buoyancy and insulation capabilities.
– Solid Polystyrene: Solid PS is found in items like disposable cutlery, CD cases, and optical lenses, where transparency and rigidity are essential.

These key differences highlight the unique characteristics of Styrofoam (EPS foam) and solid Polystyrene, making them suitable for distinct applications.


In our journey of exploring Styrofoam vs. Polystyrene, we’ve uncovered the distinct characteristics of these materials, and their common uses. As we conclude this discussion, let’s recap the key takeaway:

Styrofoam (EPS foam) and Polystyrene (solid) are two plastic materials with different properties and applications. Styrofoam is known for its insulation capabilities and is commonly used in packaging and construction, while solid Polystyrene is transparent and often used in consumer products.