Wait until you get to your table to eat. It is unsanitary and just plain bad manners to eat at the salad bar. Never put your head underneath it. When you do, the germs you breathe out, the ones on your hands, and even your hair may come in contact with food sources where they can thrive. When returning to the salad bar for a refill, always ask for another plate.
Salad bars can contain healthy, nutritious food or an unhealthy mixture of foodborne bacteria.
Make sure you are not the cause of the bacteria infestation.