I've noticed that we have a few questions about "bad things" in/on food, sometimes seeking suggestions on ways to deal with that. Whereas the nutrition tag is about getting sufficient nutrients, these questions seem to be about avoiding problematic matter. Those things fit into several different categories.
Should we have tags for each of these categories, or one tag for all of the above? Currently the best candidate is the health tag but I think we can afford a bit more precision.
Heavy metal contamination, especially from soils
Organic compounds that affect digestion
Toxic compounds added through agricultural processes
Antinutrients (like oxalic acid)
Harmful compounds produced by cooking