Red Dye 40 is a synthetic food dye that is commonly used in dairy products, sweets, and beverages. While the U.S. Food and Drug Administration and the European Union deem it safe for consumption, some studies show a link between dyes and increased ADHD or hyperactivity in children. Other studies show an improvement in behavior and attention once the dyes were eliminated. Red Dye 40 contains benzene, a known cancer-causing substance. Red 3, another red dye, causes cancer in animals, and there is evidence that several other dyes also are carcinogenic. Red Dye 40 has an acceptable daily intake (ADI) of. However, some people may be allergic to it, and potential side effects may include hyperactivity, behavioral changes like irritability and depression, allergic reaction, hives and asthma, sneezing, watery eyes, skin irritation, and migraines. If you want to minimize your exposure to Red Dye 40, you can read labels and find healthy alternatives.