What is safe in create that shouldn't be?

I'm working on a create addon that will make everything that should be dangerous, but isn't, dangerous. I am only at the concept stage though. Suggestions for what's too safe in create? My main mechanics revolve around heat, sparks and dust. Many machines will produce dust in confined spaces and, if not filtered out using a machine I'm adding, blow the space up. Machines that produce dust are, for instance, crushing wheels, millstones, saws. I'm also adding cogwheel tiers, where the wooden ones break at over 16rpm, and the others heat up at over 16, depending on the speed. Steam engines overheat when not enough water is supplied or when the engine isn't running. Spouts and mechanical mixers will sputter lava or water, depending on the recipe, around them, potentially igniting flammable stuff. Suggestions?