CI 42090

CI 42090, also known as FD&C Blue No. 1 or Brilliant Blue FCF, is a synthetic triarylmethane dye that provides a bright, stable blue color in cosmetic formulations. In this speckle variant, the dye is dispersed on a sodium sulfate carrier to create decorative visual effects in products like bath salts, scrubs, and cleansers. Formulators choose this ingredient for its excellent water solubility, vibrant hue, and regulatory approval in many countries, though it can be sensitive to pH extremes and may stain temporarily on skin contact.