Hexavalent chromium in tattoo inks: Dermal exposure and systemic risk

Safety of Inks Used in Tattoos

Since 2015, the number of articles on tattoo inks has increased significantly in recent years as more and more people choose to decorate their bodies. The introductory section presents a multifaceted psychological and social perspective. Attitudes toward tattoos in different parts of the world are taken into account, as well as the approach to the topic by different social groups. It has changed over the years and depending on the wealth of a given group. The main part is an overview of tattoo ink tests, which mainly focus on the safety of the products used, direct tests and potential allergens contained in the composition. The information contained can be summed up by the great need for ongoing implementation of further regulations in order to protect people using the services of tattooists.

Tattoos and cutaneous squamous cell carcinoma: a population-based case-control study

The prevalence of tattoos in western countries is about 20%. Tattoo ink may contain carcinogenic compounds. The aim of this study was to investigate if tattoo exposure is associated with an increased risk of cutaneous squamous cell carcinoma in individuals. In this population-based case-control study, 2857 cases aged 20 to 60 years, diagnosed between 2014 and 2017, were identified in the Swedish Cancer Registry. Statistics Sweden identified 3 random age- and sex-matched controls per case from the Swedish Total Population Register using incidence-density sampling. In 2019, participants answered a questionnaire regarding lifestyle factors, including tattoos and sun habits. We used logistic regression to investigate if tattoo exposure was associated with the relative risk of cutaneous squamous cell carcinoma. 61% of the cases and 53% of the controls replied to the questionnaire. Among the 1600 cases and the 4551 controls that participated, 15.1% and 17.6% had at least one tattoo before the index date. We found no increased risk of cutaneous squamous cell carcinoma in tattooed compared with non-tattooed individuals (incidence rate ratio, 0.95; 95% confidence interval, 0.78-1.15). Tattoo exposure was not associated with the risk of cutaneous squamous cell carcinoma in this first study of the association. However, more epidemiologic studies are needed before consensus regarding a lack of association can be reached.

Tattoo Ink Metal Nanoparticles: Assessment of Toxicity In Vitro and with a Novel Human Ex Vivo Model

Tattoo inks contain varying amounts of metal nanoparticles (NPs) < 100 nm that, due to their unique physicochemical properties, may have specific biological uptake and cause skin or systemic toxicities. The toxic effects of certified reference standards of metal NPs and samples of commercially available tattoo inks were investigated using an in vitro system and a novel human ex vivo model. In vitro toxicity was evaluated using vitality assays on human skin cells (HaCaT cell line, primary fibroblasts, and keratinocytes). No toxicity was observed for Al2O3, Cr2O3, Fe2O3, and TiO2 NPs, whereas CuO NPs showed dose-dependent toxicity on HaCaT and primary fibroblasts. Fibroblasts and keratinocytes were also sensitive to high concentrations of ZnO NPs. Reference standards and ink samples were then injected ex vivo into human skin explants using tattoo needles. Histological analysis showed pigment distribution deep in the dermis and close to dermal vessels, suggesting possible systemic diffusion. The presence of an inflammatory infiltrate was also observed. Immunohistochemical analysis showed increased apoptosis and expression of the inflammatory cytokine interleukin-8 in explants specifically tattooed with the reference standard or red ink. Taken together, the results suggest that the tattooing technique leads to exposure to toxic metal NPs and skin damage.

Lessons learned in a decade: Medical-toxicological view of tattooing

Tattooing has been part of the human culture for thousands of years, yet only in the past decades has it entered the mainstream of the society. With the rise in popularity, tattoos also gained attention among researchers, with the aim to better understand the health risks posed by their application. 'A medical-toxicological view of tattooing'-a work published in The Lancet almost a decade ago, resulted from the international collaboration of various experts in the field. Since then, much understanding has been achieved regarding adverse effects, treatment of complications, as well as their regulation for improving public health. Yet major knowledge gaps remain. This review article results from the Second International Conference on Tattoo Safety hosted by the German Federal Institute for Risk Assessment (BfR) and provides a glimpse from the medical-toxicological perspective, regulatory strategies and advances in the analysis of tattoo inks.

Exposure estimates of parabens from personal care products compared with biomonitoring data in human hair from Northeast China

Parabens (PBs), a class of endocrine-disrupting chemicals (EDCs), are extensively used as additives in personal care products (PCPs); however, distinguishing between endogenous and exogenous contamination from PCPs in hair remains a challenge. We conducted a comprehensive analysis of the levels, distribution patterns, impact factors, and sources of PBs in 119 human hair samples collected from Changchun, northeast China. The detection rates of methylparaben (MeP), propylparaben (PrP), and ethylparaben (EtP) in hair samples were found to be 100%. The concentration of PBs in hair followed the order of MeP (57.48 ng/g) > PrP (46.40 ng/g) > EtP (6.80 ng/g). The concentration of PrP in female hair was significantly higher (65.38 ng/g) than that observed in male hair (7.82 ng/g) (p < 0.05). The levels of excretion rates of MeP (ERMeP) and excretion rates of PrP (ERPrP) in the hair-dying samples (ERMeP: 17.89 ng/day; ERPrP: 14.15 ng/day) were found to be 2.52 and 2.40 times higher, respectively, compared to the non-hair-dying samples (ERMeP: 7.09 ng/day; ERPrP: 6.05 ng/day). However, the system exposure dosage (SED) results revealed that although hair dyes exhibited higher PBs, human exposure was found to be lower than certain PCPs. The results of the correlation analysis revealed that toner, face cream, body lotion, and hair conditioner were identified as the primary sources of PBs in male hair. Furthermore, the human exposure resulting from the utilization of female hair dye and serum exhibited a positive correlation with hair ERMeP and ERPrP levels, indicating in the screening of samples, excluding hair samples using hair dye and haircare essential oil can effectively avoid the interference caused by exogenous contamination from PCPs.

Potential chemical risks from tattoos and their relevance to military health policy in the United States

We summarize and consolidate disparate sources of information about the practice of tattooing and its potential implications for military population health and policy. Each branch of the United States military has policies about tattoos for service members, but these have varied over time and do not cover health protection. The number of veterans receiving disability payments and the cost of those payments has been rising over time; the broad category of skin conditions accounts for 11% of disability claims. Any additional factor, such as tattoos that may increase the occurrence of adverse skin reactions, can substantially impact veteran benefit expenses and budgets. This may be a consideration for the military as it evaluates its policies related to tattoos among service members.

Hypersensitivity to permanent tattoos: Literature summary and comprehensive review of patch tested tattoo patients 1997-2022

We outline constituents of tattoo and permanent make-up ink with regard to inflammatory tattoo reactions and population-based confounders. The comprehensive review of patch-tested tattoo patients between 1997 and 2022 shows that tattoo allergy cannot be reliably diagnosed via patch testing with today's knowledge. Weak penetration and slow haptenization of pigments, unavailability of pigments as test allergens and a lack of knowledge concerning relevant epitopes hamper the diagnosis of tattoo allergy. Patch testing p-phenylenediamine and disperse (textile) dyes is not able to close this gap. Sensitization to metals was associated with all types of tattoo complications, although often not clinically relevant for the tattoo reaction. Binders and industrial biocides are frequently missing on ink declarations and should be patch tested. The pigment carbon black (C.I. 77266) is no skin sensitizer. Patch tests with culprit inks were usually positive with cheap ink products for non-professional use or with professionally used inks in patients with eczematous reactions characterized by papules and infiltration. Tape stripping before patch testing and patch test readings on Day 8 or 10 may improve the diagnostic quality. The meaningfulness of the categorical EU-wide ban of Pigment Green 7 and Pigment Blue 15:3 is not substantiated by the presented data.

Quantitative analysis of restricted metals and metalloids in tattoo inks: A systematic review and meta-analysis

The various ingredients and impurities that can be detected within tattoo inks have been associated with a myriad of dermatologic complications. Legislation regarding these antigenic substances varies widely around the world, with Europe serving as both the research and regulatory center on these intradermal formulations. Although industry is said to be moving away from metallic and metalloid pigments in exchange for organic or organometallic dyes, surveys of commercially available inks continue to detect these elements at concentrations considered unsafe for application into the dermis. In order to better assess the formulation and safety of tattoo ink, we present a systematic review and meta-analysis of studies quantifying restricted metals and metalloids in commercially available tattoo ink products. Among the papers selected, inconsistencies were noted in the degree of specificity by which ink products were identified and the elements sampled for. In addition, the analytical targets' valency and/or solubility were not always considered in accordance with regulation criteria. Of note, chromium, by total content and that of its regulated +6 valency, exceeded its maximum allowed concentration in nearly every sample tested. Total copper content exceeded the limit for soluble copper in half of inks sampled. In descending order, concentrations of cadmium, barium, mercury, soluble copper, arsenic, zinc, antimony, and lead violated regulations in one-sixth or fewer of samples tested. Cobalt and tin levels never violated regulation. Overall, our findings indicate that unsafe levels of restricted elements continue to be detected across studies, warranting further investigation under a regulatory lens.

“For Asia Market Only”: A Green Tattoo Ink between Safety and Regulations

Due to the increasing tattoo practicing in Eastern countries and general concern on tattoo ink composition and safety, the green tattoo inks Green Concentrate by Eternal, for European and “for Asia Market Only” were analyzed, under the premise that only the former falls under a composition regulation. A separation of the additives from the pigment was carried out by successive extraction in solvents of different polarities, i.e., water, acetone and dichloromethane. The solid residues were analyzed by IR and Raman spectroscopies, the liquid fractions by GC/mass spectrometry. The relative pigment load and element traces were also estimated. We found that the European and the Asian inks are based on the same pigment, PG7, restricted in Europe, though at different loads. They have a similar content of harmful impurities, such as Ni, As, Cd and Sb and both contain siloxanes, including harmful D4. Furthermore, they have different physical-chemical properties, the European ink being more hydrophilic, the Asian more hydrophobic. Additionally, the Asian ink contains harmful additives for the solubilization of hydrophobic matrices and by-products of the phthalocyanine synthesis. Teratogenic phthalates are present as well as chlorinated teratogenic and carcinogenic compounds usually associated to the laser treatment for removal purposes, to a larger extent in the European ink. The composition of the inks does not seem to reflect regulatory restrictions, where issued.

Tattoo inks are toxicological risks to human health: A systematic review of its ingredients, fate inside skin, toxicity due to polycyclic aromatic hydrocarbons, primary aromatic amines, metals, and overview of regulatory frameworks

Today, tattooing has become very popular among people all over the world. Tattooists, with the help of tiny needles, place tattoo ink inside the skin surface and unintentionally introduce a large number of unknown ingredients. These ingredients include polycyclic aromatic hydrocarbons (PAHs), heavy metals, and primary aromatic amines (PAAs), which are either unintentionally introduced along with the ink or produced inside the skin by different types of processes for example cleavage, metabolism and photodecomposition. These could pose toxicological risks to human health, if present beyond permissible limits. PAH such as Benzo(a)pyrene is present in carbon black ink. PAAs could be formed inside the skin as a result of reductive cleavage of organic azo dyes. They are reported to be highly carcinogenic by environmental protection agencies. Heavy metals, namely, cadmium, lead, mercury, antimony, beryllium, and arsenic are responsible for cancer, neurodegenerative diseases, cardiovascular, gastrointestinal, lungs, kidneys, liver, endocrine, and bone diseases. Mercury, cobalt sulphate, other soluble cobalt salts, and carbon black are in Group 2B, which means they may cause cancer in humans. Cadmium and compounds of cadmium, on the other hand, are in Group 1 (carcinogenic to humans). The present article addresses the various ingredients of tattoo inks, their metabolic fate inside human skin and unintentionally added impurities that could pose toxicological risk to human health. Public awareness and regulations that are warranted to be implemented globally for improving the safety of tattooing.

Analysis of microstructural characteristics and components of red and yellow ink pigments used in permanent makeup

Our purpose in this study is to analyze the microstructural characteristics and constituent elements of inorganic substances added to the yellow ink and red ink pigments used in permanent makeup. We observed the microstructural properties of inorganic pigments added to the ink using a scanning electron microscopy (SEM) and analyzed the constituent elements of the inorganic pigment particles using an energy dispersive X-ray spectroscopy (EDX). In red wine-colored ink, cubic titanium dioxide with a diameter of 110 to 200 nm was the major component, and rod-shaped iron oxide was rarely observed. Most of the ingredients of taupe yellow ink were rod-shaped yellow iron oxide, and a small amount of cubic titanium dioxide was observed. Red wine-colored ink and taupe yellow ink contained lumps composed of titanium dioxide particles. In red wine-colored ink, lumps were formed by agglomeration. However, we observed that the surface of the lump composed of titanium dioxide in the taupe yellow ink had a smooth surface caused by external physical compression. The titanium dioxide particle mass which found in taupe yellow ink in this study is an artificial product. When this mass accumulates in the dermis, it may cause a color mismatch. Therefore, permanent makeup using fine pigments should be free of foreign substances that may cause trouble in the skin. In addition, there is a need to improve the quality of the ink so that the required color can be safe and long lasting in the dermis.

Analytical survey of tattoo inks-A chemical and legal perspective with focus on sensitizing substances

BACKGROUND

Tattoo inks have been reported to elicit allergic contact dermatitis.

OBJECTIVES

To investigate the labels and the contents of metals and pigments in tattoo inks, considering restrictions within the European Union.

METHODS

Seventy-three tattoo inks currently available on the market, either bought or donated (already used), were investigated for trace metals and pigments by inductively coupled plasma mass spectrometry and by matrix-assisted laser desorption/ionization time of flight tandem mass spectrometry.

RESULTS

Ninety-three percent of the bought tattoo inks violated European, legal requirements on labeling. Fifty percent of the tattoo inks declared at least one pigment ingredient incorrectly. Sixty-one percent of the inks contained pigments of concern, especially red inks. Iron, aluminium, titanium, and copper (most in green/blue inks) were the main metals detected in the inks. The level of metal impurities exceeded current restriction limits in only a few cases. Total chromium (0.35-139 μg/g) and nickel (0.1-41 μg/g) were found in almost all samples. The levels of iron, chromium, manganese, cobalt, nickel, zinc, lead, and arsenic were found to covary significantly.

CONCLUSIONS

To prevent contact allergy and toxic reactions among users it is important for tattoo ink manufacturers to follow the regulations and decrease nickel and chromium impurities.

Inorganic ions in the skin: Allies or enemies?

Skin constitutes a barrier protecting the organism against physical and chemical factors. Therefore, it is constantly exposed to the xenobiotics, including inorganic ions that are ubiquitous in the environment. Some of them play important roles in homeostasis and regulatory functions of the body, also in the skin, while others can be considered dangerous. Many authors have shown that inorganic ions could penetrate inside the skin and possibly induce local effects. In this review, we give an account of the current knowledge on the effects of skin exposure to inorganic ions. Beneficial effects on skin conditions related to the use of thermal spring waters are discussed together with the application of aluminium in underarm hygiene products and silver salts in treatment of difficult wounds. Finally, the potential consequences of dermal exposure to topical sensitizers and harmful heavy ions including radionuclides are discussed.

Contact Allergy-Emerging Allergens and Public Health Impact

Contact allergy (sensitisation) and allergic contact dermatitis (ACD) resulting from it have a considerable public health impact. For the present review, all pertinent articles were systematically searched via Medline and Web of Science™; additionally, all available issues of the journals "Contact Dermatitis" and "Dermatitis" were manually searched, covering the years 2018-2019, thereby extending and re-focusing a previous similar review. New allergens, or previously described allergens found in a new exposure context or of other current importance, are described in sections according to substance classes, e.g., metals, preservatives, fragrances. As a common finding in many investigations, a lack of information on product composition has been noted, for instance, regarding a newly described allergen in canvas shoes (dimethylthiocarbamylbenzothiazole sulfide) and, most notably, absence of co-operation from manufacturers of glucose-monitoring devices and insulin pumps, respectively. These latter devices have been shown to cause severe ACD in a considerable number of diabetic patients caused by the liberation of isobornyl acrylate and N,N'-dimethylacrylamide, respectively, as demonstrated by an international collaboration between dermatologists and chemists. Improved and complete ingredient labelling for all types of products, and not just cosmetics, must be put on the legislative agenda.

Quantitative analysis of metals and metal-based nano- and submicron-particles in tattoo inks

Exposure to metals and metal-based nano- (NPs, 1-100 nm) and submicron-particles (SPs, 0.1-1 μm) contained in tattoo inks and related health safety is currently receiving a great deal of interest. Twenty inks of different brands and colours were sampled in Italy in 2019. The SemiQuant Inductively Coupled Plasma Mass Spectrometry (ICP-MS) analysis allowed quantifying the concentration of 18 metals (Al, As, Ba, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Sb, Se, Sn, Ti, Zn) in inks. The Single Particle ICP-MS was used to detect the diameters and concentration of NPs and SPs of 9 metals (Al, Co, Cr, Cu, Hg, Ni, Pb, Ti and Zn). Concentration of metals in tattoo inks were below the recommended concentrations reported in the Resolution ResAP (2008)1 indicating ink production have shifted to purer materials and best manufacturing practices. Regarding particles, Al was found at nano- (62-80 nm) and submicron-sizes (105-140 nm). Sizes of Cr, Cu, Pb and Zn were in the intervals 42-62 nm, 44-96 nm, 26-28 nm and 26-59 nm, respectively. Titanium was at submicron-diameters (166-383 nm). In addition, Cr and Ti particles accounted for the 47% and 80% of their total concentration, respectively. Tattooing practice exposed humans to metal-based NPs and SPs and the presence of a combination of particles of different metals and/or their dynamics (e.g., dissolution) may change their bioavailability and toxicity.

Immunocompromised Districts of Skin: A Case Series and a Literature Review

BACKGROUND

The concept of immunocompromised districts of skin has been developed by Ruocco and helps to explain certain aspects of the macromorphology of skin diseases. This concept unites the isomorphic response of Koebner and the isotopic response of Wolf.

CASE REPORTS

We present different cutaneous conditions which can lead to immunocompromised districts of skin such as scars, radiodermatitis, lymphedema, disturbed innervation or mechanical friction etc. Typical and rarer skin disorders associated with them are discussed and illustrated by their observations.

CONCLUSION

At this moment, we wish to inform dermatologists and non-dermatologists about Ruocco's concept and its implications.