It is quite a common question about if Tupperware is safe for microwave. The quick answer is yes, but with some important precautions. Read on to discover the latest hindsight on the subject of plastic containers.
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 delicious 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, which can be harmful to your health. So let's reveal the safety standards of plastic products and if it is okay to microwave Tupperware.
Is Tupperware microwave safe?
Manufacturers of Tupperware containers label their products BPA-free and microwave-safe.
It means that Tupperware is microwave safe and can be microwaved without worries. But you should avoid overheating or lengthy reheating your food in a microwave.
But some studies have revealed that plastics such as Bisphenol A (BPA) and Bisphenol S (BPS) are harmful to health.
Also, some food containers are made with polycarbonate (plastic #7), which may release BPA into food during reheating it.
Can Tupperware go in the microwave?
While plastic producers consider their containers safe, what happens with microwaving Tupperware?
The problem relates to plastic production: not all plastics are manufactured similarly.
BPA (Bisphenol A) was discovered in the 1890s, but only in the 1950s it started being used to produce commercial products, including food containers and hygiene products. BPA had the effect of hardening the plastic, which made it more durable.
Over the years, the BPA has even been associated with the development of
- prostate cancer,
- infertility and miscarriages,
- type 2 diabetes, and
- behavioral problems in children.
Some studies have revealed that plastics such as Bisphenol A (BPA) and Bisphenol S (BPS) may cause hormonal imbalances.
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. The studies on in-vivo testing in Calgary (Canada) and Cincinnati (the USA) have been continued.
Nowadays, Bisphenol B is used as an alternative for BPA and BPS in the United States and several other countries. However, The National Social Security Administration (ANSES) recognizes Bisphenol B as an endocrine disruptor like BPA and BPS.
When microwaving Tupperware, the chemicals of the heated plastic can leach into the food wrapped in the plastic container.
Louise Deschêsnes, scientific manager of packaging and materials at the Food Research and Development Center in Canada, alarms
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.
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.
You should look for a microwave-safe symbol at the bottom of the container and also 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. All 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:
- Polyethylene Terephthalate (PET or PETE)
- High-density polyethylene (HDPE)
- Polyvinyl chloride (PVC or V)
- Low-density polyethylene (LDPE)
- Polypropylene (PP)
- Polystyrene (PS)
- 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, plastic numbers 1, 3, 6, and 7 must be avoided.
Suppose you can't find such symbols and plastic numbers on your Tupperware. In that case, 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 don't know 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 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 with bad smell plastic containers.
Tips for microwaving Tupperware
While it is still debatable whether you can microwave plastic Tupperware, let's summarize the tips to microwave it safely.
- Choose Tupperware products BPA-free and Phthalate-free, and read the manufacturers' guidelines for safe reheating.
- Ensure your plastic container is safe for microwaving. If in doubt, don't do this. Please, consider investing in glass, ceramic, and plastic containers specially designed to be used in 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 the migration of toxic substances into food.
- Be careful with reheating oily, fatty, or sugar-rich foods since they reach higher temperatures than the boiling point of water. It may cause the melting of the plastic and increase harm to your food.
- Reheat your food in a plastic container with the lid off. Instead of the lid, use a glass, ceramic plate, or damp paper towel.
- Don't microwave leftovers more than once at a time. The temperature that ensures the safety of the reheated food is 165°F (74°C).
- Don't store and heat food in single-use containers, aka deli containers. Most of them aren't designed to withstand microwaving. Instead, they will deform and melt in contact with heat.
- Avoid using plastic containers that are visibly damaged, stained, or with 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 internal temperature of the food boosts, which can lead to the increased leaching of chemicals into 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 pressure will cause the lid and food to explode.
Food should be covered but not sealed airtight. Instead of the lid, use a glass, ceramic plate, or damp paper towel. If your Tupperware has a lid with a steam vent cap, open it before microwaving.
Alternatives to plastic Tupperware
Glass containers are one of the best alternatives to plastic for food storage and microwave. They have the same convenience as plastic at affordable prices. In addition, major manufacturers add glass storage to their lines, making them more accessible than ever.
The only disadvantage of microwave-safe glass is that it breaks more easily. So you should be prepared for a regular restocking of your kitchen.
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, hands high levels of heat without being affected and so is microwavable. But again, not all pottery is microwave-safe due to its porous nature. 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. However, stoneware dishes without metallic lining are also microwavable and safe.
Stainless steel Tupperware
Instead of plastic Tupperware for food storage but not microwaving, you can choose food-grade stainless steel Tupperware made from 304 stainless steel. This material doesn't release harmful chemicals into food.
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, it is your decision to use plastic containers in the microwave or choose healthy alternatives.
It depends on the types of plastic. You should never microwave polyethylene terephthalate (PETE, or plastic #1) and polystyrene (PS, or plastic #6), while high-density polyethylene (HDPE, or plastic #2), polypropylene (PP, or plastic #5) are typically microwave-safe plastics.
Most plastic Tupperware containers are made of synthetic polymers such as low-density polyethylene (LDPE, or plastic #4) or Polypropylene (PP, or plastic #5).
You can place Tupperware in the microwave if it has a microwave-safe label, a microwave symbol, and is made with plastic #5 (polypropylene, or PP).
Ziploc Tupperware is microwave-safe to store, reheat, and eat your food safely. All Ziploc food storage containers are labeled as "microwave safe."
Rubbermaid Tupperware is microwave safe to reheat food, according to the manufacturer. Always look for the label "microwave safe" or microwave symbol on the bottom of the container.
Tupperware brand claims that the Tupperware lunch box is microwave safe and so can be used to pack a nutritious and delicious lunch for kids and adults.
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.