If you aren't sure whether something can go in the microwave, check the back or bottom to look for a microwave-safe label or symbol.
To see if a plastic container or wrap is microwave-safe, check the label: Products labeled “Microwave Safe” can be used in a microwave. Products labeled with an imprinted microwave symbol can be used in the microwave. This symbol is mostly used on reusable plastic storage containers.
Squiggly lines indicate that your container is microwave safe. This symbol can vary a lot, sometimes showing an image of a microwave, or sometimes a dish set below radiation waves, but the squiggly lines are a constant. Squiggly lines mean you can reheat that sucker with ease.
Plastic #2 High-Density Polyethylene (HDPE)
HDPE or high-density polyethylene is microwave safe. It has a tolerance of -40 to 266 degrees Fahrenheit before distortion. In the foodservice market, high density polyethylene is typically used for containers.
Glass and ceramic containers, along with plastic utensils that are labeled “microwave safe” are good choices. Do not use glass or ceramic that contains a metal rim.
Anything made of or containing steel, iron, copper or other hard metals should never go in your microwave. Metal surfaces reflect microwaves, which increases the heat inside the appliance and could lead to a fire.
According to Tupperware, plastic Tupperware can go in the microwave as long as it has the microwave safe Tupperware symbol. The Tupperware microwave safe symbol looks like 3-5 wavy lines, and you'll find it on the bottom of your food storage containers.
Tips for Microwaving Paper Plates
Look for a label that indicates whether the plates are microwave-safe. Read any messaging on the packaging before you toss it out, to confirm that your plates are OK to heat up. Remember that paper plates are fairly thin, so it's best not to heat up greasy or oily food on them.
Check the bottom of the container for a symbol. Microwave safe is usually a microwave with some wavy lines on it. If they container has a #5 on it, it is made from polypropylene, PP, so it is generally considered microwave safe.
This is generally considered a bad thing in microwave cookery and can lead to burns if you touch the plate with your hands, as well as melting or warping of the plate. It is made from materials which are not food safe when microwaved, due to off gassing or whatever other reason.
Call the phone inside the microwave.
If you hear no ring, your microwave is not leaking radiation. If you hear a ring, your microwave is leaking radiation, assuming the settings on your phone are correct. It's highly unlikely that your leaking microwave is a danger to your health.
As for the question about whether or not Pyrex is safe for use in the microwave oven – the answer is yes! Borosilicate glass has superior heat resistance properties compared to regular tempered glass, so glass Pyrex dishes are considered safe for use in the microwave oven.
It's safe to heat up foods in glass, ceramic, and containers with a waxy finish. This includes Chinese takeout containers—but remember to remove the metal handles prior to microwaving. You're also good to use paper goods (such as paper plates and paper towels) as well as parchment paper.
It's a bad idea to heat food in plastic.
However, microwaving in plastic containers is associated with increased leaching — the transfer or leaking of chemicals into food. Note that even if a plastic container is labeled “microwave safe,” that simply means it won't melt.
With vintage Tupperware products, dangerous elements (read: potentially toxic chemicals) come into play. If your Tupperware is old enough, it might even leach harmful chemicals and heavy metals like cadmium, lead, and arsenic into stored food.
If you're going to microwave food in a plastic container, it's best not to use the plastic lid. The concentration of steam that will be produced in a covered container raises the internal temperature of the container even further, which can lead to more leaching of chemicals into your food.
“Microwaves heat so quickly that steam builds up faster than an egg can 'exhale' it through its pores and the steam bursts through the shell,” the site warns.
But it's important to note that reheating food comes with risks, too. Food must be heated until it is 82C (176F) throughout to kill any harmful bacteria – and because bacteria can still grow each time food cools back down, you shouldn't reheat a meal more than once.
Containers made from Styrofoam or expanded polystyrene (EPS) foam are not safe to use in a microwave, unless they have a microwave-safe label. They may leach chemicals into food, which could increase the risk of some types of cancer.
Microwaves. Why do we love microwaves? Microwaves are attracted to fat, sugar, and water molecules. Microwaves cause molecules to vibrate.
Styrofoam cups, bowls, take-out containers -- whatever the type, don't put it in the microwave. Styrofoam is a type of plastic, which doesn't mix well with microwave temperatures.
Your container should state that it is oven-ready. You can look for either a picture of an oven or the temperature range printed on the bottom of the container. If you can't determine if the container is safe for the oven, contact your supplier before using it in the oven to avoid possible injury and damage.