A Ziploc® brand bag is a plastic bag with a zip lock on top of it to keep your food like sandwiches vacuum-fresh (especially if you have an air removal vacuum device available).
Aside from bags, they also come in plastic containers. According to the makers of Ziploc, their branded containers and bags all fulfill the safety requirements of the U.S. Food and Drug Administration, also known as the FDA. This includes the fact that they’re all microwaveable.
So can you microwave Ziploc bags? Signs point to yes. Keep on reading to find out more about this branded plastic container used for sandwiches and whatnot.
Related: What Can You Put in a Microwave?
So Can You Microwave Ziploc Bags?
Yes. You can microwave all Ziploc brand bags and containers. They all meet the FDA safety requirements, after all. However, you should read the specifics in regards to their microwaveable properties.
First and foremost, just because you can microwave food contained in a Ziploc bag, it doesn’t you can also cook it in the Ziploc bag. It can take freezer, refrigerator, and room temperatures. But never cooking temperatures.
Yes. You can microwave Ziploc bags _ Photo Credit by Anne James
Limitations on Being Microwaveable
The microwaveable Ziploc bags and containers meet the FDA requirements for them to be considered microwaveable. This is a fact. However, that’s not the whole story.
It can only handle temperatures linked with reheating and defrosting. No cooking allowed. If you cook something in a Ziploc bag, expect the plastic to get cooked along with your food, whether wholesale or partly.
Cooking Isn’t Recommended
Don’t cook food inside Ziploc bags. When reheating food inside these bags, you should instead microwave them in the lowest to medium setting every 30 seconds.
Don’t microwave them for a minute or more at the highest setting as though you’re cooking a hot pocket. This could make even Ziploc plastic bags have their chemicals leach onto the food despite being microwave safe. Too much high heat could melt these bags too.
Should Plastics Be Microwaved Anyway?
Some plastics you can microwave. Most plastics—particularly those with volatile organic compounds (VOCs) or plasticizers (Phthalates and BPA)—you cannot because they tend to melt or leach out VOCs or plasticizers into your food.
Long story short, you can put Ziploc sandwich bags in the microwave and heat them because they are microwave-safe. However, if you heat them up too much at the highest setting, you can poison the well (or your food) with the overheated plastic.
The Great Debate regarding Ziploc Bags
There are quite a number of people who are not convinced that it’s ever a good idea to microwave a “zip-locked” sandwich contained in a Ziploc bag. There are many who do microwave it “as is”, knowing full well that the bag is microwave-safe. However, as discussed above, there are limits to its “microwaveability”.
Are Other Plastic Bag Brands Safe?
There are other name brands other than Ziploc that have their own plastic bag with zip lock on them made by Tupperware and Rubbermaid. Entire businesses have containers that guarantee their plastic are safe for food storage.
However, whether or not they’re microwave-safe is a whole other kettle of fish altogether. With Ziploc plastic bags, they can be microwaved for half a minute at low to medium settings. Full stop.
What are Ziploc Bags Made of?
Ziploc bags are made with “film”. At least that’s what the plastic used on it is called. This film is a thin and clear type of plastic. It’s either made of HDPE (high-density polyethylene or recycling #2) or LDPE (low-density polyethylene or recycling #4).
This type of film is capable of withstanding microwave reheating temperatures but not cooking or baking temperatures. The numbers assigned to plastic packaging resins correspond to the amount of polymers used in the bag. They’re located on all plastic containers.
BPA-Free and Dioxin-Free
Yes, Ziploc bags are certified by the FDA as dioxin-free and BPA-free. They’re even designed to be recyclable. However, they’re not made from recycled materials. In other words, if you want to recycle them it’s for other uses other than as sandwich bags once they get compromised.
At What Temperature Do Ziploc Bags Melt?
Ziploc bags soften at around 90.5°C or 195°F because their “film” is mostly polyethylene plastic. In turn, the bag could start melting if the boiling water (water boils at around 100 °C or 212°F) is poured inside the bag.
The same thing can happen when the bag is submerged into water that’s boiling as well. You’ll be flirting with melting the bag by microwaving it for more than 30 seconds at the highest power setting of your appliance.
How Safe is Microwaving a Ziploc Bag?
Personally, it’s better to err on the side of caution and simply microwave that sandwich using a plate or something. People have successfully microwaved sandwiches and other sandwich-sized food in a Ziploc bag.
However, this doesn’t mean it’s completely safe necessarily. Aside from doing precautions like opening the bag to keep pressure from building inside of it, you should also examine the directions by the manufacturer closer. It should be microwaved at 30-second increments at medium or low settings.
Can You Defrost a Ziploc Bag in the Microwave?
According to Ziploc recommendations, the microwaveable Ziploc bas can be used for defrosting as long as you use the defrosting mode of your microwave. If you force defrosting something by zapping it at the highest settings that’s a no-go.
You cannot cook food in your Ziploc bag. It can survive room temperature, freezing temperatures, and most anything way below the boiling point of water. This is why it’s limited to reheating and not for cooking.
Why Isn’t Cooking Allowed for Ziploc Bags?
Cooking requires high temperatures beyond the water boiling point. The melting point of polyethylene plastic is below the temperatures required for cooking.
Even a Ziploc bag labeled as microwave-safe isn’t safe from your microwave’s cooking mode. Therefore, for safety’s sake, only use microwaveable Ziploc bags for reheating and defrosting.
Can you Steam Veggies in a Ziploc Bag?
Please don’t. Steaming ensures a higher heat transfer rate that direct boiling water contact, leading to leeching and melting of the film used to make your Ziploc bag. That sandwich is “toast” if you reach that temperature, and not in the delicious way.
Boiling water scalds, sure. However, steam burns can be far riskier than being scalded by boiling water. It’s because steam contains more energy. It has 9 times more energy than boiling water. Therefore, watch out for it.
Polystyrene Plastic or Film Can’t Take Steaming
The higher temperatures required to “merely” steam vegetable bits in a Ziploc bag is totally not worth the trouble. It’s actually better to err on the side of caution and never put your Ziploc bag in the microwave.
Just because your Ziploc sandwich bag and container is labeled as microwave-safe, it doesn’t mean that it’s completely impervious to the highest settings and heating capabilities of your microwave oven.
DO NOT Use the Ziploc Bag in the Microwave
Yes, sandwich bags are “technically” microwave-safe. However, there’s too much risk in making a mistake. A wrong button press or leaving the bag inside your microwave for too long can lead to food contamination or even plastic melting that outright ruins your food.
Can you Microwave Ziploc Freezer Bags?
Be cautious in microwaving the bag because it’s not designed to withstand high heat. It’s designed to allow microwaves to defrost and reheat food but only at recommended settings.
If you’re not confident with your reheating or defrosting skills it’s best to remove the food from the bag and put it in a ceramic or glass microwaveable bowl. Otherwise, follow manufacturer microwaving instructions to the letter.
How Long Can You Microwave Ziploc Bags?
When it comes to reheating or defrosting food, don’t overheat the contents of the bag since it might melt. The 30-second increment rule is a good rule of thumb that keeps you in control.
Additionally, you should set the power on low to medium in order to control the heat so that it doesn’t go beyond the boiling point of water or the softening point of the Ziploc plastic film. Carefully inspect the state of the Ziploc bag after every half-minute to ensure overheating is avoided.
Follow the Label Instructions
Although the Ziploc website assures that all Ziploc containers and bags meet U.S. FDA requirements for safety, it’s important to follow label instructions to avoid cooking food inside the bags.
You should also not microwave the film or plastic of your Ziploc bag for higher than the 90.5°C or 195°F to 100 °C or 212°F temperatures. Microwaving the bag in one go at a minute or longer can also result in plastic leaching or even melting when push comes to shove.
Is Ziploc bags microwave safe? In regards to microwaving Ziploc bags, the answer is that it depends on the plastic used by the Ziploc bag. All Ziploc bags can be microwaved for reheating only. If you wish to cook your food, you should put them in microwaveable containers specifically designed for food cooking.
Otherwise, the microwave-safe Ziploc is merely there for reheating purposes only. In fact, the dish inside the bag should be microwaved on medium settings and at half-minute or 30-second increments for best results.
When microwaving a Ziploc bag, place it on a microwave-safe dish, plate, or bowl. Handle the bag with care and please be aware that the food can become extremely hot after microwaving.
- Joshua Bruck, “Can you microwave Ziploc bags?“, MicrowaveMealPrep.com, June 15, 2020
- “Microwaving food in plastic: Dangerous or not?“, Harvard.edu, September 20, 2017
- Amy Reiter, “Is It Really That Bad to Use Plastic in the Microwave?“, Food Network, February 1, 2019