Kodak uses remjet backing on their color neg movie film (ECN). Remjet is basically a black carbon coating that serves as both an antihalation coating and as a film transport lubricant. Remjet must be removed by the movie film processing equipment (or by hand - which is very messy).
Movie film processing equipment is designed to remove the remjet coating from the film automatically. Conventional film processing equipment is not designed to do this and the remjet coating will contaminate the processor and any film it is processing.