Congress passed the Color Additive Amendments of 1960 to provide the Food and Drug Administration (FDA) authority to regulate the use of color additives in consumer products. The FDA listed two dyes, Orange No. 17 and Red No. 19, as safe even after studies showed these substances caused cancer in test animals, albeit at extremely low levels. The risk of cancer for Orange No. 17 was one in 19 billion. The risk of cancer for Red No. 19 was one in nine million. The FDA’s reasoning for concluding the two dyes were safe was that any lifetime risk lower than one in one million met the requirements for a de minimis exception to the Delaney Clause. The Delaney Clause of the Color Additive Amendments provided that any additive that induces cancers in laboratory animals must be denied listing as safe. The application of the Delaney Clause is strict compared to all other safety hazards that are not carcinogens, which instead undergo a multifactored risk-balancing analysis. The listing of the two dyes as safe by the FDA was challenged in the United States District Court. The nonprofit group Public Citizen (plaintiff) appealed to United States Court of Appeals for the District of Columbia Circuit.