Plastic is a synthetic or semi-synthetic material that’s found lightweight, durable, and is flexible.

Plastic serves various purposes, such as household products like food storage containers, medical devices, beverages, and other purposes.

However, you may wonder whether you can safely microwave plastic to prepare food, warm up your favorite beverage, or reheat leftovers.

What are the types of plastic?

Plastic is made mainly from oil and natural gas.

Plastic is a material made of long chains of polymers, which contains several thousand repeating units called monomers.

While they’re essentially made of oil and natural gas, you can also make plastics from renewable materials like wood pulp and cotton linters.

The types of plastic and products produced from them include:

  • High-density polyethylene (HDPE): detergent and hand soap containers, milk jugs, butter containers, and protein powder tubs
  • Polyvinyl chloride (PVC): plumbing pipes, electrical wiring, shower curtains, medical tubing, and synthetic leather products
  • Low-density polyethylene (LDPE): plastic bags, squeeze bottles, and food packaging
  • Polypropylene (PP): bottle caps, yogurt containers, food storage containers, single-serve coffee capsules, baby bottles, and shaker bottles
  • Polyethylene terephthalate (PET or PETE):  peanut butter, soda drink bottles, mayonnaise jars, and cooking oil containers
  • Polystyrene or Styrofoam (PS): packing peanuts and disposable food containers, plates, and disposable cups
  • Others include: polycarbonate, polylactide, acrylic, acrylonitrile butadiene, styrene, fiberglass, and nylon

Some plastics contain additives to achieve the desired properties of the finished product. These include colorants, reinforcements, and stabilizers.

Is it safe to microwave plastic?

Microwaving plastic can produce harmful chemicals like BPA and phthalates into your foods and drinks. Therefore, you should avoid microwaving plastic unless it’s a tagged label for this specific use.

The central issue with microwaving plastic is that it can cause additives.

However, the primary chemicals are bisphenol A (BPA) and a class of chemicals called phthalates, both of which are used to increase the flexibility and durability of plastic.

These chemicals, especially BPA, disrupt your body’s hormones and have been associated with reproductive, obesity, and diabetes.

You can see BPA in polycarbonate (PC) plastics (number 7), which have been widely used since the 1960s to make food storage containers, drinking glasses, and baby bottles.

The BPA from these plastics can leach into foods and beverages over time and when the plastic is exposed to heat, such as when it’s microwaved.

Additionally, some food preparation, storage, and serving products have swapped PC plastic for BPA-free plastic like PP.

The Food and Drug Administration (FDA) also prohibits BPA-based materials in infant formula packaging, sippy cups, and baby bottles.

Finally, it’s a good idea to avoid microwaving plastic unless — according to the FDA — the container is specifically labeled safe for microwave use.

Other ways to reduce your exposure to BPA and phthalates

Other factors that can increase chemical leaching include:

  • scrubbing containers using abrasive materials, such as steel wool, that can cause scratching
  • exposing containers to the dishwasher repeatedly over time
  • using containers for an extended period of time
  • placing foods in plastic containers that are still hot

Notably, plastic containers that seem to crack, show signs of wear, pitting should be replaced with new BPA-free plastic containers or containers made from glass.

Plastic food packaging like clingy plastic wrap can also contain BPA and phthalates.

As such, if you need to cover your food in the microwave, use wax paper, parchment paper, or a paper towel.