Can you microwave Tupperware?

Tupperware has been a generic word for food boxes for decades, and the answer depends entirely on which box you have. The brand sells lines explicitly rated for microwave reheating and other lines rated only for the fridge and freezer, and the mark on the base is the only reliable way to tell them apart. Freezer-rated polypropylene and polyethylene boxes often warp at reheating temperatures. Lids are usually softer than the base, which is why almost every microwave-safe piece tells you to vent or remove the lid.

How to do it properly

1. Turn the box over and look for the wavy-lines symbol or microwave-safe text
2. Take the lid off or set it on loosely so steam escapes
3. Heat at 50-70 percent power for anything oily
4. Let the box cool before putting it back in the freezer

What goes wrong

• Freezer-only boxes soften and lose their shape permanently
• A sealed lid can pop off and throw hot food
• Tomato-based sauces stain and pit plastic that is being run too hot

Other options

• Move the food to a plate or glass bowl
• Buy one or two dedicated microwave-safe glass boxes for reheating

Other "can you microwave" questions

• Can you microwave styrofoam? It depends — Only if the container is labeled microwave-safe, and most takeout foam is not.
• Can you microwave aluminum foil? No — No — foil reflects microwaves and the edges arc, which can start a fire.
• Can you microwave plastic containers? It depends — Only ones labeled microwave-safe — cold-storage tubs are not among them.
• Can you microwave eggs? It depends — Beaten or pricked eggs, yes. A whole egg in its shell will explode.
• Can you microwave paper plates? It depends — Plain white paper plates are fine; anything with metallic trim or a foam layer is not.
• Can you microwave metal? No — No — metal reflects microwaves, arcs at edges, and can damage the oven or start a fire.
• Can you microwave breast milk? No — No — microwaves create hot spots that scald a baby even when the bottle feels cool.
• Can you microwave takeout containers? It depends — Only if the container is marked microwave-safe — most are not, and metal-handled ones never are.
• Can you microwave cardboard? It depends — Plain dry cardboard is usually fine briefly; anything with glue, staples, wax or foil is not.
• Can you microwave glass? It depends — Yes for ordinary heatproof glass; no for leaded crystal, and never straight from the freezer.
• Can you microwave water? It depends — Yes, but very clean water can superheat and erupt when you move the cup.
• Can you microwave ceramic? It depends — Yes for plain glazed ceramic; no if it has metallic trim or is unglazed and porous.