Because brilliant black is an azo dye, it may produce adverse reactions in individuals with aspirin allergy and it may also cause hives. This food additive is also a histamine liberator, so it may aggravate or intensify symptoms of asthma. Individuals with rhinitis, urticaria, or other allergies should also avoid brilliant black.

Another side effect of brilliant black may occur in the digestive system. In the intestines, brilliant black can be transformed by bacteria into compounds that could possibly become hazardous.

Brilliant black is believed to have an effect on hyperactivity and ADHD in children. The Hyperactive Children's Support Group (HACSG) has recommended the elimination of this chemical additive from the diets of children.

Because of the many possible side effects, the use of brilliant black as a food additive is currently banned in Austria, Belgium, Denmark, France, Germany, Norway, Sweden, Switzerland, and the U.S. Elsewhere, the ADI for brilliant black varies. Depending on the country, the ADI could be up to 1-5 mg/kg bw (bw=body weight) or 0-2.5 mg/kg bw.