Jennifer23

This is inaccurate. Using all cotton will reduce the risk, but it will not eliminate it.

To find out if something might catch fire in the microwave, do this simple test: take the object (or materials you want to make it out of) and hold a lit match to it. If it can burn, it can also burn in the microwave.

This isn't a perfect test, of course... I had a rice bag char quite thoroughly even though I made it myself from 100% cotton fabric and thread, no batting, with 90sec in the microwave. The problem started in the rice, even though it would pass the match test. The fabric was getting ready to burn when I pulled it out.

There is no way to make a non-flammable bowl holder. The question is what level of risk you're willing to take. You can do it with lower risk using all cotton, or somewhat higher risk using other materials. The only way to have no fire issues is not to put flammable things in the microwave.