<p>One nice thing about chemical engineering is that you can easily get into biological applications near the end of your undergraduate program, as many chemE programs (including mine), have a biotechnology concentration. The opposite (getting into the non-biological aspects of chemE near the end of your BME program) is probably a lot more difficult, as bioE’s generally take far less than chemE’s in the way of fluid mechanics, transport processes, thermodynamics, chemical kinetics, etc.</p>