Knowing what was previously stored in the container is about the only other thing you'd need to know. Assuming it wasn't something toxic, root beer, or pickles, you should be fine. You mention that they came from a bakery, so I doubt they were used for any of that.
The only other thing I'd want to know is what the **** a Giant Eagle is doing with a bunch of plastic buckets? Don't they normally eat fish and rodents?