"The Department of Health says that we have to add at least 0.5 parts per million (ppm) and not more than ... that continue to recommend using fluoride toothpaste, in combination with fluoridated ...
In Hong Kong, 0.5 ppm (parts per million or milligrams of fluoride per litre of water) of fluoride is added to drinking water. The amount of fluoride in fluoride toothpaste is much more ...