As the adage goes, the dose makes the poison. But the same can be said for our foods—a morbid morsel to chew on during your holiday noshing.

While still safe to eat, our favorite dishes have a dark side—a striking amount are laced with toxic and deadly substances. In fact, we flirt with intriguingly dangerous ingredients not just during the holidays, but daily. Potentially poisonous substances arrive in our foods through contamination and hazardous production conditions, and toxins are also naturally present in many plants. Nearly all are present at such low amounts that they pose little risk. But, in large enough quantities or if safety monitoring fails, some of our favorite dishes could easily turn against us.

This leaves the Food and Drug Administration with the tricky task of keeping our foods safe—and knowing when they slip into the realm of poisons.