Is number 6 styrofoam microwave-safe 

Styrofoam is a widely used material found in many different forms, including cups, plates, and food containers. 

Plastic has different safety numbers, and with the increase in microwave use in the modern kitchen, they become confusing.

So is number 6 Styrofoam microwave safe?

In this article, we will help you get all the information on whether or not number 6 Styrofoam is microwave safe.

What is styrofoam?

Styrofoam is a trademarked brand of the closed cell of extruded polystyrene foam (XPS) manufactured to provide thermal insulation and water barriers.

There is another form of Styrofoam which is mostly used to make food containers, coffee cups, and a cushioning material for packaging.

This type of Styrofoam is referred to as expanded polystyrene foam (EPS). Polystyrene foam is a plastic combination of styrene and benzene.

Is Styrofoam Microwave-Safe?

The answer depends on the type of Styrofoam and the conditions under which it is used.

Most of the EPS foam containers, unless they have a label showing they are microwave-safe, are not to be used in a microwave.

The FDA approved that all Styrofoam that is microwave-safe should be labeled. It is because when Styrofoam is heated, it produces chemicals that leach into your food.

The chemicals produced are believed to cause cancer. Bringing about the need to label the microwave safe once.

Types of Plastic

Before we move to whether or not number 6 Styrofoam is microwave-safe, let us first familiarize ourselves with the different types of plastics.

There are seven types of plastic 1, 2, 3, 4, 5, 6, and 7.

These numbers are known as recycling symbols. They are found on the bottom of the container.

  • Number 1 plastic:

It is known as polyethylene terephthalate, which is one of the most generally used thermoplastic polymer resins.

This plastic is frequently used to make water and beverage bottles, food jars, salad dressing, oil bottles, cloth fibers, and mouthwash bottles.

Plastic 1 is usually clear in color and is not intended for multiple uses. PET is not microwaving safe. When heated it produces toxins that leach into your food.

  • Number 2 plastic:

It’s also called high-density polyethylene. And it’s the safest form of plastic. This type has a high strength-to-density ratio which results in superb wear resistance.

HDPE withstands heating and freezing. So, it can be used in different weather conditions. 

The number 2 plastic is used to make various items like jugs, ropes, bottle crates, stools, chairs, sturdy bottles for cosmetics, and household cleaners.

  • Number 3 plastic:

Also known as Number 3 plastic, Number 3 plastic is one of the least recycled plastics. PVC recycling number means it is strong and elastic due to softening chemicals. The plastic is used to make pipes, window and door frames, and clear food wraps.

  • Number 4 plastic:

Low-density polyethylene is one of the oldest polyethylene. It is believed to be rather safe to use. And is used to make bread wrappings, squeezable bottles, shopping bags, packaging foam, and trays.

  • Number 5 plastic:

Polypropylene plastic is the second most produced plastic. It’s light, heat resistant, and sturdy.

It is commonly used in yogurt containers, liners in cereal boxes, disposable diapers, plastic bottle tops, kitchenware, and disposable plates and cutlery.

  • Number 6 plastic:

Polystyrene or Styrofoam. This is one of the plastic recycling codes that must be avoided.

It is cheap to produce, lightweight, and can be easily formed. It is widely applied in packaging and insulation.

  • Number 7 plastic:

It refers to anything else that has not been described above. This one is found in sports bottles and equipment, car parts, baby bottles, medical and dental equipment, electrical wiring, and lids.

Plastic recycling numbers 2, 4, and 5 are the safest whereas plastic numbers 1, 3, 6, and 7 must be avoided for microwave use.

Is Number 6 Styrofoam Microwave Safe?

No, number 6 Styrofoam is not microwave safe. It’s a type of polystyrene foam that is commonly used in food packaging. 

Number 6 is often referred to as PS (polystyrene).  And it’s not recommended for use in the microwave by most manufacturers.

The reason for this is that it  has a lower melting point than some other types of polystyrene foam. 

Meaning, it will likely deform and melt when exposed to high temperatures, such as those found in the microwave.

Number 6 Styrofoam releases potentially harmful chemicals into the food when heated. 

This is because the heat can cause the material to break down and release styrene, a toxic chemical that has been linked to cancer and other health problems.


What happens if I microwave number 6 Styrofoam?

If you microwave number 6 Styrofoam, the material melts and deforms, causing the container to lose its shape.

The heat can cause the material to release toxic chemicals such as styrene and benzene, which contaminate food being heated. This poses a health risk to the person consuming it. 

How can I tell if a container is microwave safe?

The easiest way to tell if a container is microwave-safe is to check the label or packaging for a microwave-safe symbol. 

This symbol typically consists of a microwave icon with some additional text indicating that the container is safe for use in the microwave.

If there is no label or symbol, it is best to assume that the container is not microwave safe