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Can You Microwave Red Solo Cups? (Why You Shouldn’t)

You’re having cold brewed coffee you wish to take during your commute. The first thing that comes to your mind is reheating it in the microwave using a solo cup.

But can you microwave red solo cups? This is an unanswered question that needs an urgent answer.

The answer is NO. You shouldn’t microwave red solo cups. They’re made of plastics that produces BPA and phthalates when heated, the industrial chemicals cause health issues once they leach into your drink.

Our write-up today expounds why microwaving red solo cups isn’t recommended.

Related post: Can You Microwave a Solo Cup?

Why You Shouldn’t Microwave Red Solo Cups

Solo cups are the common vessels we all use in our parties for their cheap cost, readily available and conceals the drinks we’re taking accordingly. No wonder why these containers are gaining popularity day by day.

However, microwaving drinks in solo cups poses more harm than most of us can realize.

Solo cups are made of plastics, a one-time product and thus not recommended for hot liquids. Heat causes, BPA and phthalates, industrial chemicals used in making cups to leach into your drink thus ingesting it.

Microwaving solo cups as well as taking hot liquids in them is unwise and should be avoided.

BPA, the industrial chemical used in making polycarbonate plastics, causes serious health issues, especially the endocrine system.

This chemical also affects the brain and leads to blood pressure.

What Are Red Solo cups? Should I Microwave My Drink in Them? 

Red solo cups are small cups made of thick molded thermoplastic polystyrene. The cups are therefore toxic and should never be microwaved

They contain BPA which when subjected to heat leach into your drink. These chemicals can cause health issues including affecting the endocrine system.

At What Temperatures Does a Red Solo Cup Melt? Should I Microwave it? 

As said, red solo cups are made of plastic. They can’t withstand heat hence not safe for microwaving. Heat causes BPA and phthalates to leach into your drink, which when ingested leads to health complications especially to the endocrine system.

Different plastics melt at different temperatures depending on their chemical makeup and duration of exposure.

Below is a description of the different plastics and their melting points which clearly shows that melting solo cups isn’t a good idea.

  • PET plastics leach at 25degrees Celsius. We can all agree that this is way too low temperature. At higher temperatures above 50degrees Celsius PET plastics continue to increase antimony, a chemical they contain at yet a higher rate. It is therefore advisable not to take drinks in these plastics or microwave them.
  • Black plastics are not microwave safe either. Though most people think that they pose a lower risk of leaching their chemicals, they are also equally hazardous. Be sure to check for a microwave-safe label before attempting to microwave them.
  • FDA approved BPA–free plastics can only be microwaved for a maximum of 240 hours (about 1 and a half weeks). They are made of type 5 polypropylene which with time leaches into your drink causing serious health complications.
  • HDPE high density polyethene plastics are safe for short periods of time withstanding up to 248 F 120 degrees Celsius. On longtime exposure, these plastics can only withstand up to 230F 110 degrees Celsius. Their tolerance ranges from –40 to 256 F.
  • Pyrex should never be microwaved. You should not microwave cold Pyrex as it undergoes thermal degradation that makes it crack, causing damage to your microwave.
  • PVC melts at 160 to 210 degrees Celsius 320-410 F.

What is the Effect of Heat on Red Solo Cups? Will Solo Cups Melt in a Microwave?  

Most plastics melt at 170 degrees Celsius 338F.They are therefore not preferred for microwaving. Solo cups can’t be microwaved because they contain BPA and phthalates which leach into your drink causing health issues when ingested. 

Plastics undergo thermal degradation losing strength and toughness. They hence chip, crack or even break.

Solo red cups melt when subjected to heat releasing toxic fumes which damage your microwave.

Microwaving solo cups also causes them to melt, exploding the microwave. This may require a lot of time cleaning it or even damage your microwave completely.

In case your fluid did not explode, the solo cup may crack on your hands causing severe burns. I am sure no one would like such an experience.

Can I Use Any Other Alternative To Microwave My Drink? 

Although solo plates and Dixie plates are thought of being better, they’re however not microwave safe.

Some of the approved microwave-safe materials are:

  • Glass. Glass is microwave because it has no effect on one’s health and does not react with microwaves.
  • Ceramic materials. Contain stoneware and porcelain which does not react in microwaves. However, you should avoid ceramic materials with metal glazing as they may explode your microwave.
  • Microwave safe plastic containers. Plastic containers like Ziploc are microwave-safe Be sure you to check for manufacturer’s label of microwave-safe.
  • You can as well go for Styrofoam which is equally microwave safe.

Are Solo Cups Microwavable? How Can I Identify a Microwave Safe Vessel? 

We have seen that it’s wrong to microwave red solo cups. Although that’s what most of us believe, some vessels are microwave safe. Below is a guide of how to identify a microwave safe vessel.

  • Examine whether your dish is microwave safe or not. Most manufacturers indicate whether their products are microwave safe. Microwave safe dishes have a label of a microwave at the bottom with some wavy lines. In case your dish does not have this label, don’t microwave it.
  • Pour water in a glass and then place it in your dish. Adjust the microwave’s power to its highest level. You should then microwave your dish for one minute. If the dish is cold and the water is hot then it is microwave safe. If the dish is hot then it is not microwave safe. You shouldn’t pour water into the dish.


Red solo cups are unsafe to put in a microwave. Be that as it may, you may go for other options such as ceramic and glass. Be sure to check for a microwave safe label before you attempt microwaving it.

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