My boyfriend dipped a paper clip in my coloring gel and used it to decorate fondant bowling balls.... *Cringe*
I'm curious if I have to throw them away now?
Unless the paper clip is rusted, has been used for something or kept in a place that is unsanitary, it really shouldn't be an issue.
I would replace it to be on the safe side.
It may not hurt you, but would you sell a cake to someone that you know had rust in it?