Chemistry should be fun and exciting, but much preparation and skill are needed by the teacher and students in working with chemicals. Unfortunately, accidents do happen and things can blow up, but these incidents can help be prevented by knowing and following proper safety procedures. Knowing which chemicals are appropriate for the middle level classroom is a good place to start. Some chemicals, though still found in middle school inventories, are considered too hazardous to store and use. Unfortunately, some school science curricula require experiences in labs or demonstrations that have made the "what is out" list.