.....not necessarily the case in the food industry, but then the industries may be different.
I would guess that it depends on who verifies the results, i.e. for supply to retailers in the UK, if your food facility has BRC (British Retail Consortium) certification, then it has a seal of approval that says that 'generally' it is a site that has adequate GMP etc. It is often seen as a seal of approval for supply, but some retailers then apply further standards.
Could it be that there is such a standard in this industry? I have no idea and am probably grasping at straws, but I have nothing else to offer for now.....except to wish everyone a fabulous Christmas and New Year (in case I don't make it to the BB again in the next day or so).
Take care everyone and travel safely! See you all soon.