Tattoos in past cultures were were typically made from materials found in nature. This is true today among peoples living in more tribal settings. Dyes from plants and ground-up minerals would be injected into the skin using a needle or other sharp implement. Tattoo designs could reveal a person's standing in society and information about about gender, family and geographic location.
The U.S. Food and Drug Administration does not monitor the materials in tattoo pigments, inks and binders, and has not officially approved any specific ink, pigment or binder. This is because in the past there were no health concerns about tattooing, and because the organization has oversight of several other aspects of public health. Several kinds of pigments and binders are present in tattoo inks, some of which are not even publicly known.
Several substances are used in today's tattoos, including sulphides, oxides, other metallic salts, organic dyes and plastic-based solutions. Some pigment materials include titanium dioxide, iron oxide, naphthol derivates, ash-based dyes and quinoline, among other mixtures. Metals within inks include copper, nickel, lead, lithium and mercury. It is difficult to uniformly chart these different materials outside of specific studies because of the unregulated nature of tattoo ink production.
Tattoo pigments have been known to cause allergic reactions in some people. These reactions can develop immediately or years after body art is done. Some pigments and binders are considered to be toxic. A European study found that almost 20 percent of colorant materials used in tattoo inks contained aromatic amine, a carcinogen. Also, there's no guarantee that various ingredients in tattoos will remain stable throughout the wearer's lifetime.