A certificate for azo dyes exists to ensure that dyes that cleave to one of the forbidden amines are not being used for dyeing. All dyers should ensure that the supply company is fully informed about the legislation of the prohibited azo dyes. To ensure this, they should be members of the EDAD (Ecological and Toxicological Association of Dyes and Organic Pigments Manufacturers) from which they can receive their certificate. Non-ETAD member sources suppliers correlate with doubt about the origin and safety of the dyes. Dyes without certification are not advised to be used.