In the 1990s, FDA scientists developed new analytical methods that found worrisome amounts of the carcinogen benzidine in Yellow 5 and Yellow 6 food dyes. The FDA’s response to its own discovery of a carcinogen in the second and third most-widely-used dyes? It hasn’t done any tests since, let alone warn the public, ban the dyes, or restrict benzidine to safe levels. The FDA also is ignoring the fact that synthetic dyes can trigger hyperactivity and other behavior problems in susceptible children. In contrast, the European Union passed a law requiring warning labels on the few remaining foods that still contain some of the most questionable dyes.