All of the products in this category are FDA-approved for external use, eye area, and general (including lips), and thus approved for use in bath bombs. You can read more about FDA regulations in our article on the subject. We recommend water soluble dyes as the main coloring agent for bath bombs, bubble bars, etc., because they dissolve in water, need no dispersing agent additive, and are highly concentrated. When bloomed, a very small amount is needed to create bold colors! Check out our Bath Bomb Supplies, which include Stainless Steel Bath Bomb Molds, Mini Scoops and Polysorbate 80!
Don't forget: if you use micas or lakes in your bath bombs you'll need to add Polysorbate 80 to your formula in order to allow them to disperse properly.