where does red dye number 40 come from
Allura Red AC The compound is a derivative of naphthalene and a dark red powder. It usually comes as a sodium salt, but can also be used as both calcium and potassium salts. These salts are soluble in water; in solution, its maximum absorbance lies at about 504 nm.[2]:921 Its melting point is above 300 °C (572 °F).