Arsenic, cadmium, chromium, cobalt, lead, mercury, and nickel are among a group of substances commonly referred to as "heavy metals." Depending on factors such as how we are exposed to them, how often, how long, and in what amounts, heavy metals such as arsenic, cadmium, lead, and mercury can be toxic. Or, in the case of nickel, cobalt, and chromium, people can become sensitive to them. These substances in cosmetics come from minerals used as pigments and as fillers, such as clay and talc. There are some regulations and guidance to some heavy metals as cosmetic ingredients. It is important for manufactures to verify their products contain metals in right amount and do not become toxic metal content testing.