Can you microwave the boxes from wholefoods?

Answer 1

Yes and No. Microwaves work by modulating Hydrogen molecules in food. Basically they send high powered radio waves through food. When the radio waves hit hydrogen in water (H2O remember?) they cause the hydrogen to vibrate. This vibration causes molecular friction, which creates heat.

Paper has no water in it, and very very little hydrogen. It will likely not heat up much, and definitely will not burn. That being said, dyes and coatings on paper, such as plastic or wax, may contain hydrogen or water, and can heat. Melting is common with most takout containers, especially styrofoam. Plastic containers can melt, or leach plasticisors into your food. Plasticisors are the additives to plastics that cause them to be flexible and not brittle, or vice versa, and give the plastics strength. There are plastics that are microwavable, and they will be labeled as such on the bottom of the container.

You also need to check for metal in your containers, in the forms of staples or wire. Metal reflects the microwaves energy, and also interferes with the magnetron that generates these waves. You will get sparking and potentially fire in your microwave if it encounters most metal surfaces. There are some microwave safe metals (and shapes of metal) but these are all specially designed for microwave use.

As a good rule of thumb, don't microwave food in a container that is not specifically labeled as microwave safe. Older ceramics and other plates should largely be fine.