Is It Safe To Microwave Plastic Storage Bags? What You Should Know

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It's undeniable that microwaves have become one of our greatest household allies. It can do everything from reheat leftovers and thaw frozen foods to prepare scrambled eggs in a matter of minutes. That being said, the microwave has truly earned its spot as a vital kitchen appliance. According to the Bureau of Labor Statistics, more than 90% of U.S. homes own one as of the early 2000s, further highlighting its importance. 

Despite being so widespread, many people still struggle with the lack of knowledge of what should and should not be safely placed inside. Plastic storage bags, along with metal, Styrofoam containers and cardboard boxes, are among the common items you should think twice about before putting in the microwave. On top of that, there are some takeout containers you really shouldn't be microwaving for your own good. That's why double-checking whether an item is actually microwave-safe and thoroughly reading its label are both essential practices before you decide to use the microwave.  

In the case of plastic storage bags, however, there are brands like Ziploc, that are perfectly safe for defrosting or reheating food. However, that doesn't always seem to be the case. University of Michigan researchers warn that plastic storage bags don't quite belong in the microwave. The reason for this, they explain, is that they can trigger a process known as leaching or migration. This is when tiny plastic particles can move from the bag into our meal, contaminate the food, and put our health at risk. 

Leaching primarily occurs when inappropriate types of plastic are used in the microwave. These plastics can release substances like Bisphenol A (BPA), phthalates, and other additives, which can interfere with hormones. That's why single-use plastics, takeout containers, and any other plastic that's damaged or discolored are a massive microwave no-no. Still, plastic takeout containers are not completely useless. There's a genius way to use them in your garden, instead of simply tossing them in the trash. On the other hand, durable plastic containers like Tupperware, which are specially designed to withstand microwave heat, are a safe and reliable alternative. 

As for plastic storage bags, aside from being useful for defrosting and reheating, Ziploc bags aren't fit for much else. In addition, leaving their zipper open is quite important to allow steam and heat to escape when reheating foods high in sugar and fat. Otherwise, just as any other plastic bag, it could melt or burst and potentially damage your microwave. If you're using a different brand, however, make sure to strictly follow the instructions indicated on the packaging. These are usually indicated by a microwave-safe symbol or image. 

Apart from Ziploc, ClearWare Gallon Freezer Bags that come with a double zipper seal are also a great microwave-safe, leakproof, and BPA-free choice. Still, keep in mind that even microwave-safe plastic storage bags can only handle heat up to a certain point. Avoid exposing them to temperatures beyond their limit. Once you notice cracks, warping, or other signs of wear, it's time to head to the store and replace them with new ones.