Bicarbonate of soda or sodium bicarb. Tata brand.
This is an essential ingredient in the making of bath bombs and has a water softening action.
It can also be used in luxurious bath teas, milks, salts etc as a lovely addition on its own or combined with a little citric acid to add a little fizz to the product which can aide dispersal of other ingredients.
Tags: Bicarbonate of Soda