It depends on the specific industry and type of company you are referring to, as well as any regulations or standards that apply to your organization. HACCP (Hazard Analysis and Critical Control Points) is a food safety management system that is often required for companies that handle, process, or manufacture food products.
In general, the number of employees who need to be HACCP certified will depend on the size and complexity of your operations.
Typically, key personnel who are responsible for the development, implementation, and maintenance of the HACCP plan, as well as those who perform critical tasks such as monitoring and verification, are required to be trained and certified.