Is Tupperware Microwave Safe? What You Need to Know

Quick answer: Is Tupperware microwave safe? Yes, as long as the container is labeled microwave-safe or shows the microwave symbol. Vent the lid, use short heating intervals, and avoid vintage or unlabeled pieces. For hot, fatty, or acidic foods, glass or ceramic is the safer choice.

While our grandparents and parents relied on glass jars and containers, we live in the era of Tupperware thanks to Earl Tupper. His invention, airtight plastic containers, helps store all those leftovers from dinner or a party.

Or picture yourself making French crepes and storing them in a plastic container to enjoy the following day. But when you are in a hurry and have leftovers, is it safe to heat them in plastic Tupperware?

Many scientific studies have concluded that plastic potentially releases dioxins into food and drink. So let's review the safety standards for plastic products and whether it is okay to microwave Tupperware.

Is Tupperware microwave safe?

Tupperware manufacturers label their products BPA-free and microwave-safe.

So, is Tupperware microwave safe? In general, yes, and it can be microwaved without worries. But you should avoid overheating or reheating food for long periods in the microwave. 

Some studies have found that plastics such as Bisphenol A (BPA) and Bisphenol S (BPS) are harmful.

Also, some food containers are made with polycarbonate (plastic #7), which may release BPA into food during reheating. 

Can Tupperware go in the microwave?

While plastic producers consider their containers safe, what happens when you microwave Tupperware?

The problem relates to plastic production: not all plastics are manufactured the same way. 

BPA (Bisphenol A) was discovered in the 1890s, but it wasn't used to produce commercial products, including food containers and hygiene products, until the 1950s. BPA hardened the plastic, making it more durable.

Over the years, Bisphenol A (BPA) and Bisphenol S (BPS) have raised concerns about their potential effects on the human body, leading many manufacturers to create BPA‑free containers.

The good news is that since 2010, Tupperware products in the USA and Canada no longer contain BPA but may contain BPS, which is still potentially harmful. Clinical studies in Calgary (Canada) and Cincinnati (the USA) have continued.

Nowadays, Bisphenol B is used as an alternative to BPA and BPS in the United States and several other countries. However, the French food and environmental safety agency ANSES recognizes Bisphenol B as an endocrine disruptor like BPA and BPS.

When microwaving Tupperware, chemicals from the heated plastic can leach into the food wrapped in the container.

Louise Deschêsnes, scientific manager of packaging and materials at the Food Research and Development Center in Canada, warns

It is in our interest to use materials that can withstand these temperatures without there being any migration that could cause concerns in terms of food safety. There are small molecules in the plastic that can be transferred to the food, and all of these phenomena are increased by [cooking] time and heat. 

So you may consider opting for better alternatives to plastic, such as microwave-safe glass, including Pyrex glassware and ceramic.

How to tell if Tupperware is microwave safe?

First and foremost, Tupperware products aren't created for cooking but for food storage. So, choose containers that are BPA-free and microwave-safe. 

Look for a microwave-safe symbol at the bottom of the container, along with the supported temperature.

Microwave-safe symbols include three squiggly lines located on top of each other. Here are examples of microwave-safe symbols.

While manufacturers use these symbols, they aren't standardized. This means they can come in different shapes, sizes, and designs.

If you can't find a microwave sign or image, refer to plastic recycling symbols or the Möbius circles. They look like triangular arrows with numbers.

All plastics are classified into seven families (resin ID codes) and have numbers from 1 to 7:

1. Polyethylene Terephthalate (PET or PETE)
2. High-density polyethylene (HDPE)
3. Polyvinyl chloride (PVC or V)
4. Low-density polyethylene (LDPE)
5. Polypropylene (PP)
6. Polystyrene (PS)
7. Other/(PLA) other plastics

Plastic #2, also known as HDPE, and plastic #5, made with polypropylene (PP) and commonly used as food containers, are microwave-safe. However, avoid plastic numbers 1, 3, 6, and 7.

If you can't find these symbols and numbers on your Tupperware, it is best to avoid using it in the microwave or try to find the specific product information on the manufacturer's website.

Interestingly, with no regulation from the United States Food and Drug Administration (FDA), each manufacturer can interpret the term "microwave safe" differently.

So when you see the term "microwave safe" on your plastic container, it only means that your container won't warp or melt in the microwave.

If you are unsure if your plastic container can go in the microwave, do a little test. Put the dish with a glass of water in the microwave at maximum power for one minute. 

If the water is hot and the container is cold, such plastic is suitable for microwaving. If it is the opposite, don't use it.

Also, for safety reasons, throw away scratched, badly worn, foggy, and smelly plastic containers.

Tips for microwaving Tupperware

While it is still debatable whether you can microwave plastic Tupperware, here are tips for microwaving it safely.

• Choose Tupperware products that are BPA-free and Phthalate-free, and read the manufacturer's guidelines for safe reheating.

• Make sure your plastic container is microwave-safe. If in doubt, don't do this. Please consider investing in glass, ceramic, and plastic containers specially designed for the microwave.

• Reheat your food in small batches to reduce heat stress on the plastic container. 

• Don't microwave your plastic Tupperware at high temperatures (opt for medium heat) and for a long time (don't exceed 3 minutes at a time). It increases the risk of toxic substances migrating into food.

• Be careful when reheating oily, fatty, or sugar-rich foods, since they reach temperatures above the boiling point of water. This may cause the plastic to melt and harm your food.

• Reheat your food in a plastic container with the lid off. Instead of the lid, use a glass or ceramic plate, or a damp paper towel.

• Don't microwave leftovers more than once. The temperature that keeps reheated food safe is 165°F (74°C).

• Don't store and heat food in single-use containers, also known as deli containers. Most of them aren't designed to withstand microwaving. Instead, they can deform and melt when heated. 

• Avoid using plastic containers that are visibly damaged, stained, or have an unpleasant odor. Also, discard all the plastic Tupperware older than 2010.

• Finally, let your food cool down before transferring it to a plastic container. This simple step decreases the risk of leaching.

Can you microwave Tupperware with a lid on?

Tupperware lids are designed to cover containers while storing and reheating food. The lids prevent food from splashing during microwaving.

With the lid on, the food's internal temperature rises, which can increase chemical leaching into the food. 

So how should you microwave Tupperware? The answer is simple: always microwave it with the lid off. The intense steam needs a way to escape; otherwise, the built-up pressure will cause the lid and food to explode.

Cover the food, but don't seal it airtight. Instead of the lid, use a glass or ceramic plate, or a damp paper towel. If your Tupperware has a lid with a steam vent cap, open it before microwaving.

Alternatives to plastic Tupperware

Glass Tupperware

Glass containers are one of the best alternatives to plastic for food storage. They have the same convenience as plastic at affordable prices. In addition, major manufacturers now offer glass storage in their lines, making it more accessible than ever.

The only disadvantage of microwave-safe glass is that it breaks more easily. So be prepared to restock your kitchen regularly.

Ceramic containers

Opt for ceramic dishes if you don't want to switch to glass but still want something safer than plastic.

They are another excellent alternative for reheating your food in the microwave, but not all ceramics are microwave-safe. Please avoid ceramic vessels decorated with gold, silver, or other metals.

Most earthenware, or pottery, can withstand high heat without being affected, so it is microwavable. However, not all pottery is microwave-safe because it can be porous. So please refer to the product care instructions. 

In general, porcelain plates are safe in a microwave; however, not all are. For example, you can't microwave those with additional decorations. Stoneware dishes without a metallic lining are also microwave-safe.

Stainless steel Tupperware

Instead of plastic Tupperware for food storage (not microwaving), you can choose food-grade stainless steel Tupperware made from 304 stainless steel. This material doesn't release harmful chemicals into food. 

Can you reheat food in Tupperware?

You can reheat food in Tupperware as long as the container is labeled microwave-safe. Use short intervals, stir the food between them, and stop once it is warm rather than running one long cycle, which builds up heat and can warp or damage the plastic. Vent the lid or leave it slightly open so steam can escape.

Some caution helps, especially with hot, fatty, or acidic foods such as tomato sauce, since heat and oil raise the chance that chemicals migrate from the plastic into the food. If you reheat often or want to play it safe, transfer leftovers to a glass or ceramic dish first, which many experts prefer for repeated microwaving.

Is vintage Tupperware microwave safe?

Vintage Tupperware is best kept out of the microwave. Older pieces were made before current material standards and often carry no microwave-safe marking, so there is no reliable way to confirm what they release when heated. Some older plastics may also contain BPA or other additives that manufacturers have since moved away from.

If you own collectible or heirloom Tupperware, use it for cold storage and serving rather than heating. When you need to warm the food, move it to a modern microwave-safe container or, better still, a glass or ceramic dish, and keep the vintage piece for its original job.

Conclusion

I hope you find this guide on microwaving Tupperware useful. While manufacturers claim it is safe to microwave Tupperware, this is quite debatable in the modern world.

Even if your Tupperware is labeled BPA-free and microwave-safe, once the plastic reaches the temperature limit, it must not be used and should be recycled.

Still, the Center for Research and Information on Electromagnetic Radiation (Criirem) criticizes scientists for the lack of studies on the safety implications of plastic Tupperware and other household appliances.

In the end, you decide whether to use plastic containers in the microwave or choose other alternatives.

FAQ

Is it safe to microwave plastic?
It depends on the types of plastic. Never microwave polyethylene terephthalate (PETE, or plastic #1) or polystyrene (PS, or plastic #6). High-density polyethylene (HDPE, or plastic #2) and polypropylene (PP, or plastic #5) are typically microwave-safe plastics.

Is Tupperware plastic?
Most plastic Tupperware containers are made of synthetic polymers such as low-density polyethylene (LDPE, or plastic #4) or Polypropylene (PP, or plastic #5).

Can you microwave Ziploc Tupperware?
Ziploc Tupperware is microwave-safe for storing, reheating, and safely eating your food. All Ziploc food storage containers are labeled as microwave-safe.

Is a Tupperware lunch box microwave-safe?
The Tupperware brand claims that the Tupperware lunch box is microwave-safe and so can be used to pack a nutritious lunch for kids and adults.

Is old Tupperware BPA-free?
Plastic containers made before 2010 most likely contain BPA and other harmful chemicals and are considered unsafe. New Tupperware manufactured after March 2010 is BPA-free.

Is Rubbermaid Tupperware microwave safe?
Most modern Rubbermaid containers are microwave-safe when labeled as such on the base, but you should still vent the lid and heat in short bursts. As with any brand, avoid old, cracked, or unmarked pieces, and check the symbol before you reheat.

Is Tupperware dishwasher safe?
Many Tupperware containers are dishwasher safe on the top rack, away from the heating element, but this varies by product. Look for a dishwasher-safe symbol or the maker's guidance, since high heat over time can warp thinner pieces.