Exposing What’s in Tattoo Ink – You Might Be Surprised

True works of art, tattoos can include anything from lifelike portraits to intricate nature scenes. Since ancient times, people have adorned their bodies for ceremonial and religious purposes. But many people today use these decorations as a means of self-expression. However, the inks used for tattoos are not controlled in the US, leading to goods whose ingredients are essentially unknown. Scientists have now examined approximately 100 inks, and they found that even when these goods have ingredient labels, the lists are frequently unreliable. The research group also found tiny particles that might be damaging to cells.

Today, August 24, 2022, during the autumn meeting of the American Chemical Society, the researchers will report their findings (ACS). The hybrid ACS Fall 2022 meeting will be place from August 21–25 both online and in person, with on-demand access available from August 26–September 9. Nearly 11,000 talks covering a wide range of science issues are included in the meeting.

"We always found something that made me pause when we examined one of the inks," the researcher said.

According to John Swierk, Ph.D., the project's primary investigator, "I was first interested in what occurs when laser light is used to remove tattoos. We began researching well-known brands after I realized how little was truly known about the makeup of tattoo inks.

To learn more about the inks that tattoo artists employ on their clients, Swierk and his undergraduate research assistants conducted interviews with tattoo artists. The artists knew a brand they liked right away, but they didn't know much about what it included. Unexpectedly, no dye company produces pigment specifically for tattoo ink, says Swierk. "Large corporations produce pigments for all applications, including paint and textiles. The ink for tattoos also contains these pigments. He further points out that, despite the fact that tattoo parlors must have licenses in order to operate safely, neither municipal nor federal authorities have any control over the inks' actual composition.

Two components make up tattoo inks: a pigment and a carrier fluid. The pigment could be a solid substance, like titanium dioxide, which is white, a molecular compound, like a blue pigment, or a combination of the two, like light blue ink, which contains both the molecular blue pigment and titanium dioxide. The carrier solution usually aids in making the pigment more soluble and transfers it to the main layer of skin. Additionally, it has the ability to regulate the ink solution's viscosity and occasionally contains an anti-inflammatory component.

For safety reasons, tattoo parlors must be licensed in the areas where they operate, but neither the federal government nor any local authority has any control over the inks' actual composition.

The particle size and molecular makeup of tattoo pigments have been the subject of extensive investigation by Swierk's team at Binghamton University (State University of New York). These include Raman spectroscopy, electron microscopy, and nuclear magnetic resonance spectroscopy. These analyses have proven the existence of substances that are present but aren't specified on some labels. For instance, although ethanol was not specified in one instance, chemical testing revealed that it was present in the ink. The research group has also been successful in pinpointing the precise pigments that are found in some inks.

Every time we examined one of the inks, Swierk claims, "we found something that caused me pause." "For instance, 23 of 56 different inks examined to date point to the presence of an azo-containing dye." The Joint Research Center, which offers the European Union independent scientific opinion, claims that while many azo pigments are not harmful when they are chemically intact, bacteria or ultraviolet light can break them down into another nitrogen-based compound that is potentially carcinogenic.

Additionally, the team used electron microscopy to examine 16 inks, and it discovered that around half of them included particles smaller than 100 nm. Swierk declares that the size range is "concerning." "Particles this small can potentially injure cells by breaking through the cell membrane."

The data will be included to the "What's in My Ink?" website after the researchers conduct a few more experiments and get the results peer-reviewed. According to Swierk, "With these data, we want customers and artists to make knowledgeable judgments and understand how accurate the information is."

Due to the absence of FDA oversight, it is commonly unknown what tattoo inks are made of. Through various analytical techniques like LCMS, microwave acid digestion, ICP-MS, UV-visible, IR, NMR, and Raman spectroscopies, work is being done to separate the various components of the ink and identify them. Concerns about tattoo removal stem from the fact that it is unknown how the ink degrades or what products result. After laser photolysis, these photoproducts can be analyzed using similar analytical methods with an emphasis on those that could be detrimental to human health.

By AMERICAN CHEMICAL SOCIETY