Fluoride is a highly toxic substance. Consider, for example, the poison warning that the FDA now requires on all fluoride toothpastes sold in the U.S. or the tens of millions of people throughout China and India who now suffer serious crippling bone diseases from drinking water with elevated levels of fluoride.
In terms of acute toxicity (i.e., the dose that can cause immediate toxic consequences), fluoride is more toxic than lead, but slightly less toxic than arsenic. This is why fluoride has long been used in rodenticides and pesticides to kill pests like rats and insects. It is also why accidents involving over-ingestion of fluoridated dental products–including fluoride gels, fluoride supplements, and fluoridated water–can cause serious poisoning incidents, including death.
