While ingested fluoride was thought to reduce cavities when fluoridation began in the 1940’s, modern science shows that ingested fluoride brings no benefits and delivers significant risks.
Hard to believe but the FDA has never safety-tested fluoride for ingestion. Fluoride was grandfathered in before the 1938 law requiring drug-safety testing. Pre-1938, sodium fluoride was sold solely as a rat poison. The FDA regulates fluoridated toothpaste as a drug. Look at the warning on the back of the tube. (source)
Fluoridation is not about children’s teeth, it is about industry getting rid of its hazardous waste at a profit, instead of having to pay a fortune to dispose of it.