Scientists at Binghamton University (SUNY) analyzed nearly 100 different tattoo inks and found that manufacturers’ ingredient labels (when used) are often inaccurate, and that many inks contain nanoscale microscopic substances that can be harmful to human cells. particles. They presented their findings at this week’s American Chemical Society (ACS) meeting in Chicago.
According to lead researcher Johns Welker, a chemist in Binghamton, the project first started when his team became interested in tattoos as a medical diagnostic tool. This transferred to interest in tattoo laser removal, specifically how lasers cause tattoos to fade. “We realized we didn’t know much about the interaction between light and tattoos,” Swierk said in a press release at the ACS meeting. “My team studies how light drives chemical reactions, so it was a natural fit.”
That means learning more about the chemistry of tattoo ink, which isn’t very clear either. One reason for the significant gap in scientific understanding is that, at least in the US, tattoo ink makers are not required to disclose ingredients, and even if they do, there is no real oversight of whether those disclosures are correct, according to Swick.
Typical tattoo inks contain one or more pigments (giving the ink its color) in a “carrier package” to help deliver the pigments into the skin. Pigments are the same as those used in paints and textiles. They can be small amounts of solids or discrete molecules such as titanium dioxide or iron oxide (white or rust-brown, respectively). As for the carrier pack, most ink makers use grains or rubbing alcohol and sometimes add a little witch hazel to the mix to help the skin heal after the tattooing process. There may also be other additives to adjust the viscosity and keep the pigment particles suspended in the carrier package.
First, the team interviewed several tattoo artists and found that while the artists had their favorite brands, they knew very little about the chemistry of their favorite inks. Next, Swierk’s lab analyzed a wide range of commonly used tattoo inks using a variety of methods, including Raman spectroscopy, nuclear magnetic resonance spectroscopy and electron microscopy. This allowed them to identify specific pigments and other components in various inks.
They found that many ingredients didn’t appear on the manufacturer’s label, such as an ink that contained ethanol, even though it wasn’t listed on the label. The 23 inks analyzed to date show evidence of azo dyes. The pigments are generally inert, but exposure to bacteria or UV light can cause them to degrade into nitrogen-based compounds that can cause cancer.
In addition, Swierk said: “Particle sizes used in tattoo inks are typically very small—less than 100 nanometers in diameter. When you get to this size range, you start to worry about nanoparticles penetrating cells, entering the nucleus and causing damage that could lead to cancer. About half of the particles in the 18 inks analyzed by electron microscopy were in this worrying size range.
The European Commission has recently started cracking down on harmful chemicals in tattoo inks, including two widely used blue and green pigments (Pigment Blue 15 and Pigment Green 7), claiming that they are often of low purity and may contain harmful substances. “Anyone who has tattooed with blue or green tattoo inks in the U.S. should assume those pigments will be included,” Swierk said. “Most tattoo makers are stopping selling blue and green inks in Europe [in response to the regulatory crackdown], it is not necessary to change the pigment, as there is no obvious alternative. “
However, he added that while the scientific data from the EU is concerning, it is not yet final when it comes to the overall safety of the pigments. “Those special pigments have been used in tattoos for a long time,” Swirke said. “As with everything involving tattoos, the onus is on the consumer to make a decision about their particular level of comfort and then act accordingly.”
That’s why Swierk and his team created a fledgling website, what’s in my ink? According to Swierk, their research will ultimately constitute the first comprehensive survey of tattoo inks on the U.S. market. The site currently only has basic data from previous peer-reviewed studies, but once his team has completed its analysis of commercial tattoo inks and the resulting data has gone through the peer-review process, the site will be an invaluable resource for consumers about tattoo ink composition. .