Is there a right way to use a Process Control vs. an Allergen Control or can I decide which one to use?

There is flexibility provided to apply preventive controls as appropriate to the food, the facility and the nature of the preventive control and its role in the facility’s food safety system. It does not matter what you call a preventive control.

Can you really calibrate a metal detector?

The definition of “calibration” is evolving. For a Food Safety Plan if metal is identified as a significant hazard, you must determine the parameters that will enable detecting metal in your product and package, which will also depend on belt speed, aperture, etc. This is usually conducted by the metal detector supplier. Ongoing verification by the facility to ensure that the detector continues to operate as it was set up is required.