Depends on what you want to do. ChE has a lot of overlap with mechanical engineering, chemistry, materials science, and biological sciences now as well. The big ideas that distinguish it, so to speak, are designing large-scale chemical reactors, understanding heat, mass, and momentum transport, and doing chemical separations (which no other major does on the scale).
B.S. in ChE will generally get you into a process or project engineering type job. Process engineers will oversee and improve upon an existing industrial process (and there are too many examples here to list) while project engineers will be designing new processes and building factories from scratch. Generally, they will be minor partners under more senior guys or M.S./Ph.D. guys until they have the experience to do it on their own.
There's also all kinds of overlap and and tangential jobs you can take, too much for me to describe in a short post.