Using charcoal to cook your grillables is pretty safe. It's when you do lame-brained things like burn it inside (say in your garage on a rainy day) that things get ugly. Thanks to the carbon monoxide charcoal gives off while its burning, about 400 of us are sent to the emergency room each year after cooking with it in closed confines, leading to about 20 deaths. This kind of thing mostly happens mostly during the winter, when snow and ice storms cause people to lose power and fire up their grills inside. Not good, people. Not good.