An engineered scent or coloring agent may contain any combination of thousands of chemicals that are untested and potentially unsafe. Synthetic color is traditionally made from coal tar and contains heavy metal salts that deposit toxins onto the skin, causing skin sensitivity and irritation. Synthetic colors are usually listed as color and a number or listed as “colorant”. Synthetic fragrance is usually listed as “fragrance”. These umbrella terms do not require disclosure under the federal law’s classification of trade secrets.