The only "paint" that is really considered safe for sure around chins where they can reach is powder coating, it's what is used on cages and chin safe wheels. I'm honestly not sure which holds powder coating better.
Some people said in the past that Rust-Oleum is safe, the kind that is safe for human kids toys, but I'm not sure anymore. Resently I've read people are now saying it's not safe, I'm not sure if the formula changed or if people discovered long term effects. It's probably only safe so long as the chin doesn't chew on it, so only the outside of the pan. If you do go with Rustoium then yes you have to let it air out for a minimum of 2 weeks in a dry place.