Red 40
Red 40 is a name under which Allura Red AC, also known as FD&C Red No. 40, may appear in an ingredient list. It is a synthetic azo dye, not a plant extract, oil, or mineral pigment. The substance has sodium-bound sulfonate groups, a feature consistent with its presentation as a water-soluble dye.
Red 40: what it is
Red 40 is a name under which Allura Red AC, also known as FD&C Red No. 40, may appear in an ingredient list. It is a synthetic azo dye, not a plant extract, oil, or mineral pigment. The substance has sodium-bound sulfonate groups, a feature consistent with its presentation as a water-soluble dye.
Allura Red AC, FD&C Red No. 40, and E129 are names used for the same substance in chemical and regulatory references. Lake forms also exist, where the dye is combined with an insoluble base; finding Red 40 on a label alone does not establish that it is the lake form.
Red 40: what it does in cosmetics
In cosmetics, Red 40 is used to add colour to the product. In a gel, shampoo, or makeup item, it can contribute to the formula's visible shade and help the colour seen in the package or during application match the product's intended look. This is an appearance function; the dye is not added to moisturise, treat, or alter skin or hair.
United States federal regulation lists it for colouring cosmetics and sets particular conditions for products intended for the eye area. That authorisation explains its use as a dye, but it is not evidence of a skincare effect or a benefit for the skin or hair.
Red 40: conditions and care
In the United States, only Red 40 and its aluminium lake may colour cosmetics intended for the eye area. Use must follow current good manufacturing practice and avoid oxidising or reducing agents that could affect the dye's integrity.
Products containing this ingredient
See which products include it and the name used in each composition.
