Recent Examples on the WebToday, they are often synthesized from a chemical derived from petroleum called naphthalene to make a final product called an azo dye. Lorne J. Hofseth, The Conversation, 9 Dec. 2021 The following textile ingredients are also prohibited: toxic heavy metals, formaldehyde, aromatic solvents, GMOs and their enzymes, and azo dyes that release carcinogenic compounds. Lindsay Talbot, Marie Claire, 19 July 2018 The following textile ingredients are also prohibited: toxic heavy metals, formaldehyde, aromatic solvents, GMOs and their enzymes, and azo dyes that release carcinogenic compounds. Lindsay Talbot, Marie Claire, 19 July 2018