Too much iron in your body will poison you. Too much water will deplete your electolytes, and put stress on your body, and can kill you. Oregano is a muscle relaxer and can cause severe gastric problems if enough is eaten. Most herbs have some kind of medicinal quality that can hurt you if to much is ingested.
Stainless steel, cast iron, copper, aluminum, they all can kill, especially when the pans are used to clunk someone on the noggin.
Even pure oxygen can kill you. If you breathe from a scuba tank that contains pure oxygen, at depths of 30 feet and below, the gas becomes poisonous. Ordinary air becomes poisonous below 90 feet. Below 120 feet, if I remember correctly, the nitrogen in air needs to be replaced by helium.
I read an elegant definition of what we, as organic life creatures are; a hydro-electrical mechanism. I add to that. We are a hydro-electrical-chemical processing engine. Anything out that can disrupt the orderly chemical reactions, will disrupt the engine.
Ok, yes, I'm a strange man.
Seeeeeeya; Chief Longwind of the North