Quick Answer: You probably shouldn't microwave paper coffee cups. Certain materials used in the making of these cups can be problematic. Below, we'll cover this and other good reasons to reheat in a microwave-safe container instead.
But first, let's learn what coffee cups are made of...
What Are Coffee Cups MADE oF?
When you get a coffee in a to-go cup at a coffee shop, you're usually getting a disposable paper cup with a plastic lid.
But paper is not the only material in the cup. If you've noticed a sort of film on the inside, it's a coating of wax or plastic that keeps your beverage from seeping out and turning your paper cup to mush.
Whereas paper cups were once made leak-proof with clay, today this is typically achieved with polyethylene, a type of plastic. Both plastic and wax materials make coffee cups unrecyclable with regular paper items.
The fact that the majority of paper coffee cups are manufactured with polyethylene poses a big problem where microwavability is concerned.
One study found that microwaving a product made with plastic tends to cause estrogenic activity, or the mimicking of estrogen in the body, which is linked to changes in reproductive organ function, obesity and other health concerns.
Here's one another issue: Coffee cups can potentially come unglued or ignite with microwave heating. Clearly, it's best to think twice before warming up your to-go cup in the office microwave.
For more tips and on microwaving food and beverages, head over to our guide on the best microwave toaster oven combo.
Despite the fact that most throw-away coffee cups are constructed with paper and plastic waterproofing, there are some other options out there.
These alternatives include:
- Recycled paper coffee cups
- Styrofoam coffee cups
- Regular foam coffee cups
Let's break each one down.
Recycled paper coffee cups can be made with plastic coating, and they could also contain glues and materials that shouldn't be microwaved. Remember, too, the fire part mentioned earlier.
Styrofoam is sometimes microwavable, but only if it says so on the product. Foam coffee cups, on the other hand, should never be microwaved, or they could melt.
The safest way to go about warming up your cold coffee is to put it in a container you know if microwave-safe first. It might be a microwavable mug or glass bowl, but you'll know that it won't cause any hazardous issues.
If a coffee cup were to be microwavable, it would say so on the bottom. eramic drinkware, but unfortunately, standard disposable paper coffee cups might not have them.
It's possible to double-check on the manufacturer's website. You may even see a warning against microwaving the company's products.