Whether as a guest from the outside, as a consultant, or as an employee from headquarters or another site, touring a food plant is an opportunity to be taken seriously and seized as a teaching moment. Common sense and good manners dictate that you introduce yourself to your host and to others you may meet. Each plant may have its own safety and sanitation requirements, but most will require that a visitor take off jewelry (except simple wedding bands, usually) and wear a distinctive badge, clean…