The problem is, there are very many chemicals, those chemicals in many ways power our modern world, and they can all end up in drinking water or ingested by some other means. If you took every chemical off of the market that didn’t go through a randomized controlled double blind study, billions of people would die. Literally. How many people are fed thanks to fertilizers and pesticides that we know would be actively harmful if you consume them in quantity? Or at least don’t know would be unharmful.

It’s not practical to ban everything that we don’t know can be ingested safely. It’s just not even an intelligent idea. It’s merely a response to hysteria.