Chemical Purity and Toxicology of Pigments Used in Tattoo Inks

Abstract

The safety of tattoo inks has obviously increased in Europe since the existence of European Union Resolution ResAP(2008)1, which resulted in the improved quality control of pigment raw materials due to the definition of impurity limits that manufacturers can refer to. High-performance pigments are mostly used in tattoo inks, and these pigments are supposed to be chemically inert and offer high light fastness and low migration in solvents. However, these pigments were not developed or produced for applications involving long-term stay in the dermis or contact with bodily fluids. Therefore, these pigments often do not comply with the purity limits of the resolution; however, it is required that every distributed tattoo ink does not contain aromatic amines and not exceed the limits of heavy metals or polycyclic aromatic hydrocarbons. Current toxicity studies of pigments underline that no ecotoxicological threat to human health or to the environment should be expected. However, the pigment as well as its impurities and coating materials must be considered. In order to evaluate the safety of pigments according to their impurities, two different validated sample preparation methods are necessary: (1) simulation of their long-term stay in the bodily fluid of the dermis and (2) simulation of cleavage due to laser removal or ultraviolet exposure. The development of standardized, validated and well-adapted methods for this application has to be part of prospective efforts. Concerning legislation, it might be appropriate that the first regulative approaches be based on those of cosmetics.

Hexavalent chromium in tattoo inks: Dermal exposure and systemic risk

“…However, inks used for tattooing were not developed or produced for applications involving a long‐term presence in the dermis or contact with bodily fluids. Therefore, some inks do not comply with the purity limits of ResAP(2008)1, even though it states that every distributed tattoo ink should not contain Cr(VI) above the limit . In addition, the limit for Cr(VI) requires that it is linked to a clearly defined analytical method, whereas present recommendations for Cr(VI) in tattoo inks do not mention any analytical method.…”

“…Therefore, some inks do not comply with the purity limits of ResAP(2008)1, even though it states that every distributed tattoo ink should not contain Cr(VI) above the limit. 10 In addition, the limit for Cr(VI) requires that it is linked to a clearly defined analytical method, whereas present recommendations for Cr(VI) in tattoo inks do not mention any analytical method. Failing to provide an appropriate method may lead to invalid and questionable results, which often cause legal disputes that are ultimately resolved by a judge with regard to the method that should have been applied.…”

“…Another important problem is that pigments used in tattoo ink formulation are originally produced for other applications (such as textiles, dyes, car paints, and plastic pigments) because they have good light‐fastness properties. However, they generally contain impurities such as Cr(VI) in Cr oxides, nickel, copper and cobalt in iron oxides, aromatic amines in azo‐colorants, and polycyclic aromatic hydrocarbons in carbon black . A survey conducted on the Italian market showed a level of total Cr (tCr) exceeding the safe dermatological limit of 1 mg/kg in 62.5% of cases in 56 tattoo inks .…”

“…However, they generally contain impurities such as Cr(VI) in Cr oxides, nickel, copper and cobalt in iron oxides, aromatic amines in azo-colorants, and polycyclic aromatic hydrocarbons in carbon black. [9][10][11] A survey conducted on the Italian market showed a level of total Cr (tCr) exceeding the safe dermatological limit of 1 mg/kg in 62.5% of cases in 56 tattoo inks. 12 Clinical knowledge of tattooing complications is based on case reports.…”

Safety of Tattoos and Permanent Make up (PMU) Colorants

“…A short time ago, the manufacturers of inks had no regulations to follow and many of these products caused adverse reactions to the skin. Today the microbiological quality of tattoo ink and PMU products is good, and products manufactured in the EU have high production standards [10]. Ink and PMU should be produced in a sterile environment to be microbiologically stable for several months after opening.…”