Can you microwave Styrofoam? (Detailed Guide)

Nowadays, you see Styrofoam cups, plates, and takeout containers everywhere. Especially in the street food shops and cafes. If you want to avoid cleaning dishes or looking for low-budget one-time use containers. In that case, you also can go for Styrofoam.


While using Styrofoam, you may wonder if Styrofoam is microwave safe? No, you should not microwave Styrofoam. Styrofoam is made of polystyrene, a type of plastic. It starts to melt in contact with heat. Styrofoam is not edible and can cause several health hazards if it goes into your stomach.

What is a Styrofoam cup?

Styrofoam is a non-reusable one-time uses cup composed of a type of plastic name polystyrene. Polystyrene is a polymer with a long chain of small molecules of monomers. That is a hydrocarbon form such as benzene and ethylene.

They are also composed of 98% air or gas, making them lightweight and floated. The heat tolerance of Styrofoam is also very low; they start to soften at the temperature of 100° Celsius. That means it starts to decompose at the boiling temperature of the water.

There are two types of Styrofoam available.

Styrofoam cup

Traditional Styrofoam:

  • Traditional Styrofoam

Traditional Styrofoam is normal regular Styrofoam. It is available in cups, plates, and takeout containers.

Primarily used in cafes and street food vans and also in birthday functions, marriage functions, anniversaries, or parties. You can use it at household gatherings for serving cake, fruits, pudding, and coffee.

But never put traditional Styrofoam cups in the oven, nor bring them in contact with direct heat.

  • Microwave safe Styrofoam:

These types of Styrofoam cups are newly invented. The food and Drug Association (FDA) has allowed it to go under the microwave. But don’t consider you can cook with it under high heat.

You must be very careful with this, even if it is microwavable. Don’t forget that it is still made of plastic polymer. It will not survive under high heat.

Manufacturer of microwave-safe Styrofoam cups also does not recommend putting them in the microwave for more than 30 to 40 seconds.

However, these cups are not reusable or recyclable. These cups are not fully biodegradable. Still, they are popular for meager cost and takeout purposes.

Is it safe to microwave Styrofoam?

If you don’t want to clean up your dishes, looking for alternates of ceramic, glass, or cardboard items, then you can use Styrofoam. But you might be thinking, can you put Styrofoam in the microwave?

It is not safe to use Styrofoam in the microwave. When you heat Styrofoam in the microwave, the high electromagnetic radiation passes through Styrofoam. And because of its shallow heat tolerance capacity, it can mix up with foods by melting.

Thus, the human intestine cannot digest polystyrene; it can cause stomach infections and diseases like ulceration, abdomen pain, vomiting, etc.

However, newly invented microwave-safe Styrofoam is also available now. You can put them into the oven with precautions.

Is it safe to put Styrofoam in an oven?


Styrofoam is not an ovenproof material. Those materials with heat tolerance of at least 300°F to 400°F can be used in the oven. Styrofoam is composed of polystyrene, a type of plastic that holds 98% of the air to make it too light in weight. And that starts to decompose at 212° Fahrenheit and totally melt at 470° Fahrenheit.

It is clear that putting Styrofoam in the oven is unsafe.

Things to consider before microwaving Styrofoam

Well, this is not recommended for Microwave Styrofoam. But still, if you want to put Styrofoam in the microwave, you should keep some tips in your mind.

  • Choose microwave-safe Styrofoam: Nowadays, Microwave safe Styrofoam cups are also available. If you want to heat your food with Styrofoam, you should use microwave-safe Styrofoam. Even though you found Microwave safe Styrofoam, never put it in the oven for more than 30 to 40 seconds. Styrofoam is not designed for cooking in the oven.
  • Set low power: Set the lowest power in the microwave settings. It is recommended to set the power level to not more than 10 to 30. The power level can produce more heat even at low temperatures.
  • Set low temperature: Do not set the temperature up to 75°F to 120°F. It is evident that. Styrofoam starts to melt at 212° F. By melting; it can mix up with your food and contaminate them.
  • Set short time: Never put Styrofoam in the microwave for more than 30 to 40 seconds; otherwise, it will melt. The human digestive system cannot digest polystyrene.
  • Never reheat: Never try to reuse your Styrofoam for heating purposes. Throughout, after one time heating up. No matter whether it is ovenproof or not.

However, it is better not to put Styrofoam in the microwave for food safety.

Can you make coffee in the oven-safe Styrofoam cups in the oven?

Well, you cannot make coffee in the oven-safe Styrofoam cup into the oven. But you can serve hot coffee in a Styrofoam cup. To make coffee in the oven, you have to heat it for at least two to three minutes. At this time, the cup will melt for sure.

You can choose another way, take an oven-safe Styrofoam cup. Then pour hot water into it, and mix with coffee powder and sugar. Now enjoy. You don’t need to put your cup into the oven to make coffee.

Can you microwave Styrofoam for 30 seconds?

You can microwave Styrofoam, which is microwave-safe, only for 30 to 40 seconds. You cannot put traditional Styrofoam in the microwave. But I personally suggest it is better not to microwave Styrofoam whether it is microwave safe or not.

Microwave produces heat by generating electromagnetic radiation. Styrofoam is very light in weight; it does not have heat resistance. When heat passes through the Styrofoam, polystyrene polymers start to decompose, and as a result, they soften at 212°F and form in the liquid.

What can be used instead of Styrofoam?

Styrofoam is not so eco-friendly and is not recommended for oven use. So, finding an eco-friendly alternative to Styrofoam that can be used in the oven is better. We can go for

  • Cardboard container: Cardboard/ paperboard can be great alternatives to Styrofoam. They are more heat resistant than Styrofoam. Still, you cannot use it for a long time. But it definitely can be used longer than Styrofoam. Never reuse paperboard cups for heating purposes.
  • Bamboo one-time containers: bamboo plates and cups are durable, biodegradable, low cost, environment friendly, leakage proof, and ovenproof they can withstand the temperature of 250° Fahrenheit. Therefore, you cannot cook in it. Bamboo plates and cups are not health hazardous; they are not made of any toxic chemicals.
  • Aluminum foil containers: Aluminum foil is a thin container composed of 98.5% aluminum. The rests are iron and silicon. That means aluminum foil is a non-toxic compound. If you are concerned about health, it will be the best choice. The heat tolerance of an aluminum container is 300° Fahrenheit to 400° Fahrenheit. You can put them into a Microwave for an extended period than cardboard, bamboo cups, and Styrofoam. Actually, it is a great deal indeed.

They are completely biodegradable and budget-friendly. And heat tolerant than Styrofoam.


Styrofoam cups are famous for takeout coffee, juice, ice cream, etc. these are easy to carry out, affordable, and durable. Instead of so many benefits, this polystyrene is a type of plastic. You cannot put them into the oven; they are neither biodegradable nor reusable. Let’s use paperboard or cardboard instead of Styrofoam.