[chefwriter]

I'll take a quick crack at this.
I'd start with a list of every ingredient on the menu. So one container for each to start with. As in, tomatoes in the box sit in cooler, then they get sliced and go in a container. Each prepped ingredient will need a ninth or sixth pan for action and a container for backup/storage. Then you want to change the containers frequently so you should have one available while the dirty one is being washed. So now we are up to two containers for each ingredient. Ingredients like onions, relish, tomatoes, lettuce, etc. Not all ingredients will take the same size container so you'd have to allow for that.
The hamburg rolls won't need a container but the hamburgers will.
Include in the list everything on the menu that won't come in it's own container.
Of course, you can always utilize empty sour cream containers and the like. But they aren't always all purpose.
Anyway, I'd start with two per ingredient.

 

[chefwriter]

Jimyra, I'm sure you are correct but I see lots of restaurants do this.
For the sake of discussion, I don't know what the NSF standards are or what the local health department might say if asked. I've never seen a restaurant get cited for using such containers. If the container held food when it was purchased, then it must be food safe according to somebody's standards. Many containers holding pre made products are quite sturdy, able to withstand the dishwasher to be sanitized. It seems a shame to add them to the landfill after a single use. The rectangular plastic fish boxes seem to be the most popular but certainly not the only ones used.

 

[chefwriter]

Just passed the servsafe about six months ago. I don't recall any mention of container use. I've been taking food safety courses since the early eighties and have never seen anything about this.
I'd be skeptical even if it's true now that it isn't some legislation passed on behalf of the container industry. Food Safety is a great bugaboo to enable passing unnecessary legislation for the sake of a politician's career.
I'd also like to know how the container is food safe if a coating can come off, thus making it not food safe. No guarantee it wouldn't come off the first time.
If the pickle bucket is washed, I don't see how that's not as safe as any other container used after washing. As with any other container, how it's handled makes more of a concern. Stacking dirty containers inside each other, leaving them on the floor, not being properly washed and any number of other issues might compromise food safety. But either the container is safe or it's not. If originally used for food, it's safe. If not, it should be labeled as such.