Bath bomb

A bath bomb is a consumer product used during bathing. It was invented and patented in 1989 by Mo Constantine, co-founder of Lush Cosmetics. It is a compacted mixture of wet and dry ingredients molded into any of several shapes and then dried. Bath water effervesces at the surface of a bath bomb immersed within it, with attendant dispersion of such ingredients as essential oil, moisturizer, scent, or colorant.