Borax is an additive used to control acidity as well as as a source of the mineral boron in some multivitamins. Borax is a sodium salt of boric acid.
Boric acid studies in animals have shown it to affect fertility and damage the reproductive organs. There is concern that intake over time can cause kidney damage and renal dysfunction.
The FDA has banned the use of borax in foods. It is permitted only in sturgeon caviar within the EU.
E285, Sodium tetraborate, Sodium borate, Disodium salt boric acid, Sodium tetraborate decahydrate