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Can you put Styrofoam in the oven?

Can you put Styrofoam in the oven?

Styrofoam is a lightweight material used to make food containers and cups. These items are widely used in restaurants, and you’ve probably brought home some food in a Styrofoam container.

But you may have wondered: can food be reheated in these containers?

Can you put Styrofoam in the oven?  

You should never put Styrofoam containers in the oven. Styrofoam, made from expanded polystyrene, does not withstand high heat. It will start to soften at 212°F and melt at 464°. You can use Styrofoam containers to keep food in the fridge, but never reheat or cook with it in the oven.

In this article, you’ll learn all about Styrofoam, how it reacts with heat, and safe ways to use Styrofoam items.

What is Styrofoam?

The term Styrofoam is a trademark of The Down Chemical Company, which manufactures Styrofoam by extruding Styrofoam.

In the United States, the word Styrofoam refers to a type of expanded polystyrene.

Before we get into what polystyrene is and how Styrofoam is made, let’s go over the differences between extruded polystyrene and expanded polystyrene:

  • In the case of extruded polystyrene, the manufacturing process consists of mixing it with other ingredients by melting them.
  • For expanded polystyrene insulation, heat or steam is applied to molds filled with polystyrene beads. This causes them to expand and stick together.

Polystyrene is a plastic material used in the manufacture of many everyday products. It is derived from the monomer styrene.

When made into a foam-like material, Styrofoam is most prized for its cushioning properties. This type of Styrofoam is about 95% air, which makes it buoyant.

If you look closely at a piece of Styrofoam, you will see the many white spheres. They are the particles that have expanded to form a concrete object, be it a glass or a box.

Styrofoam beads are much smaller than the already expanded spheres you might see in a piece of Styrofoam. If you have these beads on hand, you can do some easy experiments to get a clear idea of how Styrofoam is made.

Put these beads in some kind of metal mold that you can close well. Do not fill the mold with beads, but only fill 1/3 of it with them.

Boil the mold for a few minutes. Take out the mold and let it cool. When you open it, you will see that the accounts have been greatly expanded.

Styrofoam beads will also expand if you microwave them with a small amount of water or steam them.

What is Styrofoam used for?

Styrofoam is used in many take-out food containers, plates, and cups. This type of container is light and comfortable for storing cold foods.

Your food has almost certainly been delivered or picked up in a Styrofoam container. It is quite ubiquitous today.

What temperatures can Styrofoam withstand?

If you’ve ever held a Styrofoam container in your hand and felt how light it is, you might be worried about putting it somewhere hot. It gives the feeling that the box will melt immediately.

What is the melting point of Styrofoam?

As we have already said, Styrofoam are expanded polystyrene beads. The temperature at which these beads melt is 464°F (240°C).

However, Styrofoam containers will begin to soften long before the heat reaches this degree. 100 °C (212 °F) is sufficient to soften containers of this material. (That’s just the temperature it takes to boil water!)

With this information in mind, extreme caution is advised any time you have a Styrofoam object near heat.

Can you put Styrofoam in the oven?

As you probably guessed, you can’t put Styrofoam in the oven and there are two compelling reasons for this:

  1. Styrofoam containers do not hold up well to heat. As we have said, they begin to soften at 100 °C (212 °F). To reheat food in the oven, you’ll need to set the oven to a medium temperature, which will typically be between 320 and 350°F. Attempting to reheat food in a Styrofoam container below 212°F will be useless, ruining the box and probably your food.
  2. Even though you could put the Styrofoam in the oven, eating hot food from Styrofoam containers is never recommended.

Although some restaurants may put hot food in Styrofoam containers and eating it a few times won’t cause irreversible damage, you should certainly avoid doing this when you’re at home and can easily transfer your food to a suitable container.

What happens when you put Styrofoam in the oven?

If you put a Styrofoam container or cup in a hot oven, it will start to decompose.

Leaving the Styrofoam in the oven at a high temperature will cause it to melt into a soft, sticky mass. Some oil may come out of the burned Styrofoam as it contains styrene. The latter is an organic compound and is an oily liquid.

For this to happen, you will need your oven to be very hot, reaching the melting point of polystyrene.

Safe materials for reheating food in the oven

There are multiple options for oven-safe materials. Here you have some of them.

  • Metals : Cast iron and stainless steel skillets are safe for reheating foods in the oven.
  • Glass : Oven-safe glass dishes are another great option. The best thing about these platters is that you can also serve food on them. Do not use pans that have plastic or wooden details.
  • Ceramic : Ceramic dishes can also be put in the oven. However, always make sure to check the label to see if the particular dinnerware is oven safe.

What happens if you accidentally burn the Styrofoam?

Styrofoam releases dangerous chemicals when it burns. The gases and chemicals released by burning Styrofoam are toxic to the environment.

Not only that, they can also harm your health. Lung damage is an example of the damage that can be caused by burning Styrofoam.

But don’t panic if you’ve once left a Styrofoam container in the oven to heat up a take-out meal. Burning Styrofoam once won’t do much harm to you or the environment.

What happens when you heat food in Styrofoam?

If you’re still waiting for your favorite kitchen appliance to come save the day, please stop for your own good. Microwaving Styrofoam is also not recommended.

Since Styrofoam containers are predominantly made of Styrofoam, they release and soften chemicals just as they would in the oven.

However, keep in mind that microwaveable Styrofoam has been developed to withstand oven waves and this material will be safe to eat. You just have to be sure that it is what you have.

Microwaveable Styrofoam - What is it?

Traditional Styrofoam containers are not safe for use in the microwave. However, there are microwaveable Styrofoam containers on the market that make things easier and safer.

These types of Styrofoam containers are made with safer materials and do not release chemicals when microwaved.

That being said, you should never assume if the container is microwaveable or not. What you should do is check if there is a label that clearly indicates that the container or glass is safe to be used in the microwave.

If you can’t find the label, err on the side of safety and reheat the food in another container that you’re sure is microwave safe. It’s better to prevent than to cure!

Microwave food safely

If you’re still on the fence about whether to microwave Styrofoam, do so as safely as possible by following these simple rules:

  • Transfer the food from the Styrofoam container to a plate or container that is microwave-safe.
  • Do not leave metal utensils in the food to avoid sparking.
  • Spread the food on the plate so it heats evenly and reaches a safe internal temperature.
  • Stir food or turn the plate when reheating very cold foods to avoid leaving cold spots, which can harbor bacteria.

What should you use Styrofoam containers for?

Styrofoam containers are great for storing cold foods. You can put the leftovers in a Styrofoam container and store it in the fridge.

Styrofoam cups can be used for cold drinks. Avoid using these glasses for hot drinks. Although Styrofoam cups are said to keep drinks hot longer and are comfortable to hold, they are not recommended for use with any hot liquids.

Use paper cups for hot drinks. They are much safer. Also, it is much easier to recycle paper cups.

You should also avoid using Styrofoam containers for acidic foods. A hot dish with tomato sauce, for example, should not be eaten in a Styrofoam container.

This suggests that drinks with high levels of acidity, such as citrus juices and cocktails, should be drunk in glasses made of other materials. Crystal glasses, for example, are an elegant and sustainable option.

You can even avoid using Styrofoam cups for alcoholic beverages, as well as bowls, plates, and containers for oily foods.

In a word, you can use Styrofoam containers and cups for anything that isn’t acidic, oily, alcohol-based, or hot.