Milk glass is microwave safe as well as dishwasher safe.
Glass cups are usually microwave safe and ceramic mugs are also microwave safe.
If the glass cup is not microwave safe it will usually say so on the bottom of the cup but not always.
A microwave can explode.
However microwaves rarely explode although it's possible.
Boiling water too long or leaving the microwave on too long can cause the microwave to catch fire or cause an explosion and fire.
Explosions from microwaves are rare.
Most explosions that happen in microwaves are the food that actually explodes and not the microwave.
Never start an empty microwave.
Without food or a container to absorb the microwaves, the beams are bounced back to the magnetron.
This could damage the machine and may even start a fire.
If the food has a high water content, like an egg or potato, the water expands and turns to steam.
Without a way for the steam to escape, the internal pressure rapidly builds until the food explodes.
In order to reduce the odds of food exploding in your microwave, you want to give the steam a place to escape.
Simply take a fork and pierce the food item several times.
It's the same technique you've been using all along before heating those frozen dinners.
Do not operate the oven while empty.
This can cause damage to the oven or create the possibility of a fire.
If, by accident, the oven should run empty for a minimal amount of time (approx 5 min), no harm is done.