Can You Microwave Coffee In A Styrofoam Cup?

Coffee is a beverage that gets thousands of people (including me) up in the morning each day. It keeps them going with their long days and busy routines. It is an essential item for them, whose absence can make them less motivated and productive.

I, too, like thousands of others, am a hardcore coffee lover (no exaggeration!). I can’t go a day without my daily dose of coffee. Sometimes I even have to go through multiples cup to keep myself going, especially with my hectic job as an editor. 

Our company’s kitchen only has a microwave, styrofoam cups, and other basic essential items available. So the question of whether it was possible to microwave coffee in styrofoam cups gained attention. And as the resident researcher of the company and a diehard coffee fan, everyone looked at me.

I put on my editing glasses and got straight to work. The end result is this article, which I’ll be sharing with you all so you can also survive the stressful work hours!

can you microwave coffee in a styrofoam cup

Can You Microwave Coffee In A Styrofoam Cup?

Yes, it is completely acceptable to microwave coffee in a styrofoam cup. But, you need to read the label on the styrofoam before you put it into the microwave. 

If it says that it is microwave-safe, then you don’t need to worry at all. But if it says nothing about its status as microwave friendly or not, it is better not to risk it.

One more thing you will need to be vigilant about is the amount and duration of heat you’re applying. 

Styrofoam cups can melt in the microwave. So even after their impeccable quality of keeping warm things warm and cold things cold, many people tend to steer away from them. Because who wants to open the microwave and find their coffee ruined due to a melted styrofoam cup.

You can prevent this outcome by being a little careful and patient with the heat power and duration. Microwave the cup for thirty seconds or less with the microwave settings at medium to low power. 

Styrofoam and polystyrene are the perfect temperature conservers. They will keep your food exactly how you like it. There are two types of styrofoam cups that you need to know about:

Regular Styrofoam

Using regular styrofoam for storing purposes is fine but when it comes to heating then it is a big no. Regular styrofoam melts and breaks down in the microwave. It can also seep the toxic chemicals produced during the breakdown into your food.

Microwave-Safe Styrofoam

This is a newer product created with safer materials. It lowers the risk of hazardous chemical levels. Not only is it FDA approved, but it’s also designed to remain stable at higher temperatures. So you can microwave this type of cup without any worries.

How Can You Differentiate Between Regular Styrofoam And Microwave-Safe Styrofoam?

You can tell if a cup is safe to put in the microwave by looking for the microwave-safe symbol on it. It is going to be either at the bottom of the cup or on the surface. The symbol is usually a few squiggly horizontal lines. It can even be an embossed microwave with squiggly lines inside it.

Is It Safe To Microwave Coffee In Styrofoam Cup?

can you microwave styrofoam for 30 seconds

Microwaving microwave-safe styrofoam cups is not completely safe according to FDA standards. However, there are some that may be which would only require careful attention to the intensity of heat and the duration of time the cup spends in the microwave.

Once you are sure about your cup being microwave-safe by identifying the label saying so, you can put it in the microwave. The power needs to be medium to low and the recommended time is around intervals of 30 seconds. Any more than that can risk your coffee getting contaminated.

Styrofoam is a type of polystyrene that is used for industrial purposes. But at the same time, it has a lot of value when it comes to its domestic uses.

Styrofoam cups are easy to carry, affordable, widely available, and lightweight. They are great insulators and can keep your coffee warm for extended periods. It is a cheap alternative to reusable cups that warm the coffee in the safest possible way.

What Happens If You Put Regular Styrofoam In The Microwave At High Temperatures?

If you microwave traditional styrofoam that is not labeled as microwave-safe, it will melt or break down inside the microwave. 

Even if you can’t visibly identify any damage, the microwaves can cause a highly toxic chemical called Styrene to seep into your coffee. Styrene is very dangerous as it can pose a great threat to your health and reproductive system.

How Long Can You Microwave Coffee In A Styrofoam Cup?

If you’re a regular coffee drinker who microwaves coffee in styrofoam cups, then there are some precautions you must be aware of. These will allow you to safely and effortlessly heat a cup of coffee. 

First of all, you must ensure that your microwave is on medium to low power. Second, heat it for as less time as you can and only put the cup in for intervals of thirty seconds at a time. 

Usually, coffee takes less time to heat because of its high water contents, which absorb heat more rapidly. It will take about a single thirty-second round in the microwave to warm it up throughout. 

But if it doesn’t, you can reheat it again after the first thirty-second interval. Heating the coffee in the styrofoam cup for a longer interval might result in a melted cup. Or in the worst-case scenario, your beverage can catch fire because of the toxic chemical release!

Related: Can you Microwave McDonalds Coffee

Tips For Heating Coffee In A Styrofoam Cup In The Microwave 

When you think of putting a styrofoam cup into the microwave, there might be several doubts that will pop up in your mind. But don’t worry! Microwaving your coffee in a styrofoam cup can be a very easy job if you’re following these basics tips:

  • Use a Microwave-Safe Cup: Always opt for a microwavable styrofoam cup if you want to end up with safe and edible coffee.
  • Set the Microwave to Medium Power: Setting the microwave to medium heat will make sure that the styrofoam cup doesn’t start melting. Also, it will ensure that it does not release any toxic substances. Such substances could catch fire or be poisonous to humans.
  • Heat for 30-Second Intervals: Coffee will take less time to heat up compared to food as it has high water content. Heating in short intervals will prevent the coffee from boiling in the microwave and will halt any toxic chemical release.
  • Do Not Reheat Styrofoam Cups: If you’ve used a cup to heat your beverage once, then don’t use it again.
  • Do Not Use Damaged Cups: If you notice any damage to your styrofoam cups, like dents or blisters, don’t put them in the microwave.
  • Be Careful When Adding Sugar: If you’re adding sugar to your coffee, you need to be careful. Remain attentive throughout the microwaving process to ensure that the coffee doesn’t bubble up and spill over.


All this research about microwaving coffee in a styrofoam cup relieved me and my fellow staff members of this worry about how to heat our coffee during work hours.

Styrofoam cups are cheap, light-weight, and easy to use. Sometimes I even use them to heat my coffee at home. Because after a hard day at work, I no longer look forward to washing any extra utensils! 

So even if you want to use a styrofoam cup to heat your coffee instead of getting your dishes dirty, feel free to do so! It really is a great shortcut and addition to your knowledge not only for your professional life but also for your cozy comfort nights!


Are there any health risks associated with drinking out of a styrofoam cup?

Traditional styrofoam can melt or break down once microwaved and release toxic chemicals that could seep into food or drinks. Therefore, it is important to make sure your styrofoam cup is labeled ‘microwave safe’ on the label or bottom before microwaving it.

Are microwave-safe containers the same as plastic and polystyrene containers?

No, microwave-safe containers are not the same as plastic and polystyrene containers. Microwave-safe containers are specifically designed with materials that can withstand heat during microwaving, while most plastic and polystyrene containers cannot handle the high temperatures of a microwave oven and may melt or warp when heated.

Could traditional styrofoam melt or break down if microwaved?

Yes, traditional styrofoam could melt or break down if microwaved, releasing toxic chemicals that could seep into food or drinks.

Is it possible to microwave coffee in a styrofoam cup?

Yes, it is possible to microwave coffee in a styrofoam cup as long as it is labeled ‘microwave safe’ on the label or bottom of the cup.

Does microwaving coffee in a styrofoam cup release toxic chemicals?

Traditional styrofoam can melt or break down once microwaved and release toxic chemicals that could seep into food or drinks, although this risk is minimized if the cup is labeled ‘microwave safe’.

How should the power level and time intervals be set for microwaving coffee?

The intensity of heat should be set at medium to low power with 30 seconds intervals when microwaving coffee.

What type of container should I use to keep my beverages warm in a microwave oven?

To keep your beverages warm in a microwave oven, it is best to use glass, ceramic or other approved non-plastic containers that are labeled as “microwave safe”. Avoid using any type of plastic container or polystyrene foam containers as they may release harmful chemicals into your beverage if heated too quickly. Also avoid using styrofoam coffee cups or other expanded polystyrene foam container due to their potential damage caused by heat exposure.

Why should I avoid microwaving polystyrene containers?

Microwaving polystyrene and plastic containers can cause them to melt or warp as they cannot withstand the high heats from a microwave oven. Additionally, certain chemicals used in the manufacturing process of these materials may be released into your food when heated which could be potentially hazardous. Therefore, it is best practice to avoid microwaving with any type of plastic and/or polystyrene container including takeout boxes and styrofoam coffee cups made from either extruded or expanded polystyrene foam.

How do I know if my food container is microwave safe?

Always check for a “microwave safe” label on all food storage products prior to putting them in the microwave so you know that these items have been tested according to safety standards for use in providing protection against possible health hazards associated with heating foods in a closed container. If there is no labeling indicating “microwave safe” then it would be best practice not use that particular product as an item suitable for microwaving.”

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