Quote Originally Posted by LowriderS10 View Post
Yes, I know to look for the C-41 on the film, but I heard rumours that certain B&W films while not C-41 can still be developed in a C-41 facility...obviously that was wrong.
Conventional B&W films processed in the complete C-41 process will be ruined; the bleach step will remove the silver image, resulting in a completely blank strip of film. I know because the employees running a local CVS minilab swore up and down that they could process my B&W film a few years back. I'd not been doing much photography for a while, so I figured minilabs had progressed since I last checked. The employees then had the nerve to claim my camera was at fault when they handed me back my completely blank film.

That said, there is a grain of truth in there: If you process a conventional B&W film in C-41 developer, omit the bleach, use a wash or stop bath, fix it in a fixer (C-41 or any conventional B&W fixer), and then wash it normally, it'll be fine, provided the time and temperature of the C-41 developer was suitable for the film in question. In other words, B&W films are compatible with the C-41 developer, but not with the C-41 process as a whole.