Science, Tech, Math › Science Tattoos, Red Ink, and Sensitivity Reactions Share Flipboard Email Print Red tattoo ink is associated with more reactions than other colors. Kristina Kohanova / EyeEm, Getty Images Science Chemistry Chemistry In Everyday Life Basics Chemical Laws Molecules Periodic Table Projects & Experiments Scientific Method Biochemistry Physical Chemistry Medical Chemistry Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate By Anne Marie Helmenstine, Ph.D. Chemistry Expert Ph.D., Biomedical Sciences, University of Tennessee at Knoxville B.A., Physics and Mathematics, Hastings College Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels. our editorial process Facebook Facebook Twitter Twitter Anne Marie Helmenstine, Ph.D. Updated July 03, 2019 If you have a red tattoo, you're more likely to experience a reaction than if you went with another color. Here's an e-mail I received about tattoo inks:"Does all red ink have nickel in it? I was told by the tattoo artist that if I can't wear inexpensive jewelry I should not use red ink in a tattoo. I cannot. Whatever metal or whatever is in the ink would cause the same reaction I get to inexpensive jewelry. That would cause a problem. She will not use it on me. Would this be the same for pink or orange or any color with any amount of red in it? Someone else who has had numerous tattoos told me they never heard of that and she reacts to inexpensive jewelry."My response:I'd trust the tattoo artist over someone who has numerous tattoos, since she is more likely to know the composition of the ink and whether or not her clients have had trouble with a particular color. Another artist might offer different advice and may use an ink with a different chemical composition. Key Takeaways: Reactions to Red Tattoo Ink Any tattoo ink has the potential to cause a reaction. The risk derives from any of a number of components in the ink, including the pigment, the carrier, and chemicals added to keep the suspension sterile.Red and black inks produce the highest reported number of reactions. The pigment in these inks may be linked to problems.The most toxic red pigment, cinnabar (HgS), is a mercury compound. Its use has largely been phased out.Organic pigments are less likely to cause reactions or interfere with medical diagnostic tests. However, they degrade over time. Some molecules produced from degradation include carcinogens. Why Red Tattoo Ink Causes Reactions The issue with the color red is the chemical composition of the ink. In particular, it has to do with the nature of the pigment used for the color. The carrier for the ink (the fluid part) may also play a part, but it is more likely to be common to other colors. Some reds contain iron. Iron oxide is a red pigment. Basically, it's powdered rust. While it may not cause a reaction, it's a rusty-red rather than a vivid red. Iron oxide inks (which also include some brown inks) may react to the magnets in an MRI scan. Small particles, particularly in red and black inks, have been known to migrate from the site of the tattoo to the lymph nodes. Not only can migrated pigment molecules cause health issues, but they may also appear abnormal on medical diagnostic tests. In one case, a woman with extensive tattoos had 40 lymph nodes removed because a PET-CT scan mistakenly identified the migrated tattoo pigment as malignant cells. Brighter red pigments include toxic metals, such as cadmium or mercury. Fortunately, the mercury sulfide red pigment, called cinnabar, has been largely phased out of ink formulations. Cadmium red (CdSe) remains in use and may cause redness, itching, flaking, and other problems. Organic pigments cause fewer reactions than the metal-based reds. These include the azo pigments, such as Solvent Red 1. Solvent Red 1 does not cause as many issues as iron, cadmium, or mercury reds, but it can degrade into o-anisidine, a potential carcinogen. Degradation occurs over time from ultraviolet light exposure (from sunlight, tanning beds, or other sources) or from bacterial action. Azo pigments like Red Solvent 1 also degrade when a tattoo is removed using a laser. While red ink is well-known for causing sensitivity reactions there are other colors made by mixing red. The more dilute the pigment (like in orange or pink) the lower the chance of a reaction from the red component, yet the risk is still present. Sources Engel, E.; Santarelli, F.; Vasold. R., et al. (2008). "Modern tattoos cause high concentrations of hazardous pigments in skin". Contact Dermatitis. 58 (4): 228–33. doi:10.1111/j.1600-0536.2007.01301.xEverts, Sarah (2016). What chemicals are in your tattoo? C&EN Volume 94, Issue 33, p. 24–26.Möhrenschlager M, Worret WI, Köhn FM (2006). "Tattoos and permanent make-up: background and complications." (in German) MMW Fortschr Med. 148 (41): 34–6. doi:10.1007/bf03364782Thompson, Elizabeth Chabner (July 2015). "Tattoo Ink or Cancer Cells?". Huffington Post.