Red Solo Cup: the iconic plastic cup that has swept the nation over the years and has inspired one of Toby Keith’s most well known songs.

The burning question we will be answering today is for all of the college students, campers, or anyone else out there who is in a pinch for a coffee cup.

Can you put hot coffee (or any hot liquid) into a red solo cup??

The simple answer to this question is yes, of course you can pour your coffee into a plastic cup. No one is going to stop you. 

The real question is.. should you be doing it?

It is not unknown that there are some health concerns when you heat up certain types of plastic. So today were going to dive into the nitty gritty of the plastics world!

We will cover what these cups are made of, potential health issues, and some alternative options that may be better for you and the environment.

So, without any more introduction, here is the answer to the question…

Can you (or should you) put hot coffee in a red solo cup?

To kick off answering this question, we need to learn about the world of plastics. Which types are good to use, which to stay way from and when they start to melt.

The Seven Main Plastics

There are seven different categories of plastics that we mainly use. If you look on the bottom of your Tupperware or plastic coke bottle, you’ll probably see the recycling symbol with a number inside of it.

That number represents what type of plastic material the item is made out of and if you can recycle it.

The seven main plastic types are as follows.

  1. Polyethylene terephthalate (PET)
  2. High density polyethylene (HDPE)
  3. Polyvinyl chlorine (PVC)
  4. Low density polyethylene (LDPE)
  5. Polypropylene (PP)
  6. Polystyrene (PS)
  7. Bisphenol and others

The most commonly used plastic is plastic #1 or PET. Water bottles, Gatorade bottles and condiment bottles are made up of this type of plastic.

You will also find a number of cups being made from #4 (LDPE) or #6 (PS) plastics. These will be your typical plastic or Styrofoam cups.

Since each plastic has a different purpose, there are a few that are suitable to use for food and drink while some you should definitely stay away from.

What are red solo cups made of?

Solo Cup has a few different types of disposable cups on their website. These are the classic red plastic solo cup, a see-through colored version and a run of the mill plastic cup.

The clear cups are listed as being made with the #1 plastic (PET) that we just talked about while the red solo cups & see through colored cups are made with a #6 plastic, or polystyrene.

Both plastics are able to be recycled and are reported to be BPA free.

Bisphenol A or BPA’s are found in many plastic & metal items we use every day.

Over time, pronounced negative health effects such as hormone disruption and low vitamin D levels have been linked to BPA consumption.

Since then, it has been advised to stay away from BPA’s whenever possible.

Melting point of plastics

A very important things to keep in mind when it comes to plastics is their melting point.

When plastics are exposed to heat, they degrade faster leading to toxic chemicals leaching into the environment around them.

Plastic #1 (PET) has a melting point of 255 degrees Celsius (491 degrees Fahrenheit while plastic #6 (PS) has a melting point of 100-120 degrees Celsius (212 to 248 degrees Fahrenheit).

These temperatures may seem extremely high, but in reality, the boiling point of water falls at 100 degrees Celsius or 212 degrees Fahrenheit.

Note: This temperature drops the higher above sea level you go.

So, if you find yourself in Colorado, the boiling point of water may be closer to 95 Celsius or 209 Fahrenheit due to the high elevation.

With coffee experts arguing that the ideal temperature for a cup of coffee is around 160 to 185 degrees Fahrenheit, the melting point of plastic #6 (and red solo cups) is not far off.

Potential health problems from using plastic cups

Plastic Leaching & Micro-Plastics

One of the main concerns when it comes to putting hot liquids in plastic cups is plastic leaching and microplastics (a term I’m sure you’re familiar with)

Both definitions are as follows:

Plastic leaching: when the chemicals from the plastic leak out into the surrounding environment.

Although plastic leaching is inevitable, it is known that heating plastics only increases the amount of leaching that occurs.

Microplastics: tiny plastic particles that result from both commercial product development and the breakdown of larger plastics

Microplastics on a fingertip


It may seem like microplastics would not be an issue when it comes to using plastic cups, however, a recent study testing the level of microplastics found in liquid before and after being in a plastic found:

the microplastic abundance in water reached 723–1,489 particles cup−1 after 5 min exposure and increased significantly with increasing residence time

Think you can drink your coffee before the plastic degrades?

Sudha Goel, an assistant professor from the Indian institute of technology, stated that 

In the 15 minutes it takes for (hot) coffee or tea to be consumed the microplastic layer on the cup degrades and releases 25,000 micron-sized particles into the hot beverage.

Essentially, this means that when using any plastic cup, especially with a hot drink, you will be most likely be consuming microplastics and any chemicals leaching from the plastic cup.

Chemicals Released

Many of the extremely harmful chemicals found in plastics are thankfully not used in food & drink items.

However, there are still many chemicals that are found our everyday plastic items.

Nonylphenol is a plastic found on the “chemicals of concern in plastics” produced by the Australian government back in 2021.

Unlike many of the other chemicals on the list that are found mainly in PVC, this chemical is found is Polystyrene or plastic #6.

If you remember from earlier in the article, this is the plastic that red solo cups are made out of.

Common chemicals that can be released as well are BPA’s and phthalates which can lead to other health concerns such as lower fertility rates.

Thankfully, as we discussed before, red solo cups are BPA free.

Side effects from ingested plastics

Obviously, plastics were never made to be ingested. So, the side effects that come with ingesting microplastics and chemicals from plastic cups cannot be great for us.

The Endrocine Soctiey states that the chemicals leached from plastics can contain “endocrine-disrupting chemicals (EDCs)”.

These can harm the body’s hormone system leading to a variety of health issues such as cancer and diabetes.

These EDC’s can stay in the body for an extended period of time and cause cumulative effects over your lifetime.”

Environmental Impacts

The environmental impact of plastic cups brings us back to the microplastic argument.

Plastics are everywhere in our day to day lives. So much so that there is a garbage patch in the middle of the ocean that is filled with plastic we just can’t seem to get rid of.

Plastic cups can be fantastic because of how inexpensive and convenient they are. However, being a single use plastic item, their impact on the environment adds up quickly.

To put it in perspective a bit more, research found that in the United States back in 2020,  “219.73 million Americans used disposable cups and plates in 2020”

Even further, it was found that the entire world “produces around 350 million tonnes of plastic waste each year”.

If you multiply that by the 0.5% of plastic that ends up in the oceans, you get 17,500,000 tons of plastic still making their way in the ocean each year.

The locations of the great pacific garbage patch

The Coffee Experience

Taste Difference

Obviously one of the biggest factors into a good cup of coffee is the taste!

Have you ever used a cheap coffee machine and found it tasted slightly off?  Have you left a bottle of water in the car and when you tried it the taste was a bit funky?

This change in taste happens when plastic, especially when its heated, and starts to degrade. Therefor your quality of coffee might decrease if you decide to put it in a plastic cup.

Temperature Retention

Each material has different insulating properties, meaning each material can keep hot for different amounts of time.

Metal has a very high insulating property, hence why if you get a quality metal thermos, your drinks will stay long for ages.

This property is a one of the many downfalls of using plastic cups for hot beverages.

Although the plastic cup will keep your beverage hot, it only will do so for around 1-2 hours according to The Commons. 

This is a short amount of time compared to the better alternatives we are going to discusses further below.

Alternatives To Red Solo Cups

The good news is that there are so many other options for the type of cups you can use to avoid some of the negative health effects that come with plastic cups.

Some of the more popular options are as follows:

How to choose the right alternative cup

So, you want to make the switch! Congratulations! There are a few different factors to consider before investing in a new travel or reusable coffee mug.

1. Price point

Thankfully at this point in time there are so many reusable cups out there, you can find one at pretty much any price point.

I have found that the majority of reusable coffee cups are in the price range of $10-30 USD, with the higher quality items, like this Stanly, being at the upper end of this range.

A quality reuseable mug may seem like a big investment at first but trust me it pays for itself overtime.

An additional bonus is that many coffee shops offer discounts when you bring it your own cup, so you can save a bit of money on your morning coffee as well.

Tip: If you don’t want to splurge just yet, a popular choice (and one of my favorites) is this Contigo mug. It’s inexpensive and good quality for the price!

2. Durability

I have added this section purely because I am a major clutz and I’m sure a few of you out there are as well.

Some of the most popular takeaway cups on the market, like this Keep Cup, are made of glass or ceramic materials.

These materials are all fantastic alternatives to plastic as we discussed above, but depending on you as a person, some may be better than others!

As I mentioned above, I tend to be prone to breaking things, so having an extremely breakable travel mug is out of the question for me.

So, before you buy one, think about the likelihood of you dropping it or it getting damaged in your day-to-day life.

3. Heat retention

Obviously, this is one of the most important things. No one wants a cold cup of coffee!

I have had travel mugs that kept coffee hot for over 6 hours and some where you had an hour to drink it before it goes luke-warm.

If you want your coffee to stay hot for longer periods, think getting a travel mug in the higher price range.

These typically keep liquids hot for ages and you’ll never have to worry about cold coffee again.

4. Size & Bulkiness

Some companies specifically make their cups to fit cupholders in cars while some you’ll have no chance of getting it to sit in that cupholder.

The size and width of the bottom of the cup may be something to consider if you’re constantly in situations where you need to set it down but have limited space.

Many companies offer various sizes in each model of their mugs, so take a peek to see if your preferred brand has one that works for you!

Bonus: There are cup holder adapters now! Click here to check out a popular option.

Summary: Should you be putting hot coffee in a red solo cup (or any plastic cup)?

Like I mentioned in the beginning of this article, you can absolutely put hot coffee into a red solo cup or any plastic cup for that matter! No one is going to stop you.

Although there are a few benefits to using plastic cups such as convenience, there are some major negatives to putting hot liquids into plastic cups such as

  • health risks from plastic leaching and microplastics
  • environmental impacts
  • taste & quality changes

Because of these risks and negative impacts from using hot drinks in red solo cups, there are some better alternatives out there.

If you’re on a budget, try using solo paper cups.

You don’t have to spend a lot up front, but you still protect yourself from the potential chemical exposure from warm plastics.

Glass, stainless steel, and ceramic mugs travel mugs are also fantastic environmentally friendly alternatives, though the price may be a bit higher.

All in all, I would only recommend using red solo cups for cold beverages only as recommended by the company.

It may be a bit less convenient, but it may be worth it in the long run.

As always, thank you for reading today’s article! Do you have a favorite reusable mug? Tell us below in the comments!


You may also enjoy these other articles on the Procaffinator website.

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Have a great rest of your day and keep on procaffinating!