To help us understand the hazards of food safety and their control, see Appendix 6: Common Hazards Found in Retail Food Establishments.
The identification and control of these hazards may require help from outside resources, one resource being part of the Hazard Analysis and Critical Control Points (HACCP) program. But once this is done, the main responsibility for providing a safe food product rests on the employees of the retail establishment, with strong support and training from their management.
Providing a safe and nutritious product is an everyday activity. Maybe the most important factor is educating the employee about why something is done and the consequences to safe food if it is not.