If you are concerned about food toxins and health, you may want to avoid store-bought microwave popcorn - the bags are treated with PFOA and may be a major source of toxins.
I thought about buying an air popper but found that some air poppers, at least, contain plastics that are also potentially harmful, especially when heated.
Then I discovered a quick and easy alternative. I buy popping corn (meant for stovetop or air poppers), pour a handful (nothing else) into a plain, clean paper lunch bag, fold the top of the bag several times, and microwave it.
In my microwave, one minute does it. Any longer, and it burns. (Although I can typically remove the unpopped kernels from the first batch, put them in for another minute, and increase the yield.)
After microwaving the dry kernels, add salt and melted butter if you wish.
My wife uses a one time purchased multi use microwave (apparently microwave transparent plastic) popcorn bowl. I'm less of a popcorn eater than she.
Similar to your paper bag, you have to be a little careful with the time but if you're careful with your type of popcorn (which she is anyway -- some yield fewer scraps than others) and use the microwave timer, it comes out just right every time.