Scientists explore chemistry of tattoo inks amid growing safety concerns

The scientists at the State University of New York analyzed nearly 100 different tattoo ink and found that the manufacturers' ingredient labels were often inaccurate and that many of them contained small particles that could be harmful to human cells. The findings were presented at the meeting of the American Chemical Society.

The project began when John Swierk's group became interested in tattoos as a tool for medical diagnostics. The laser light causes tattoos to fade. Swierk said that they didn't understand much about the interaction between tattoos and light. Light can drive chemical reactions, so it was a good fit for my group.

It was necessary to learn more about the composition of tattoo ink. In the US, at least, manufacturers of tattoo ink aren't required to reveal the ingredients, and even when they do, there is no real oversight of whether those disclosures are correct.

The ink's color is given by one or more pigments within a carrier package. Paints and textiles use the same pigments. For white or rust-brown colors, titanium dioxide or iron oxide can be used. Grain or rubbing alcohol can be added to the carrier package to help the skin heal after tattooing. In order to keep the particles suspended in the package, there may be other things that can be done.

The team interviewed several tattoo artists and found that they didn't know much about the chemistry of their favorite ink. Swierk's lab used a wide range of methods to analyze commonly used tattoo ink. They were able to identify the ingredients in the various ink.

They found that many ingredients weren't listed on the manufacturers' labels, such as one ink that contained a substance that wasn't listed. The ink analyzed so far shows evidence of azo. Exposure tobacteria or UV light can cause pigments to degrade into a nitrogen-based compound that can cause cancer.

Swierk says that tattoo ink particle sizes are often very small. If you go down to that size regime, you start to have concerns about nanoparticles penetrating into cells, getting into the nucleus and doing damage, potentially causing cancer. Half of the ink analyzed had particles in this size range.

The European Commission is cracking down on harmful chemicals in tattoo ink because they are often of low purity and can contain hazardous substances. Swierk said that anyone getting a tattoo in the US with blue or green tattoo ink should assume that those colors will be included. Most tattoo manufacturers have stopped selling blue and green ink in Europe because there is no obvious replacement at the moment.

The EU's scientific data is concerning, but it's not a conclusive conclusion as to the safety of the pigments. Swierk said that the pigments have been used for a long time. It is incumbent on consumers to make a decision about their comfort level and then proceed accordingly.

Swierk and his team have created a website. The first comprehensive survey of tattoo ink in the US will be constituted by their research. There is currently only rudimentary data from prior peer-reviewed studies available at the site, but once his team completes its analysis of commercial tattoo ink and the resulting data has passed through the peer review process, the site will serve as a valuable consumer resource for information about the composition of tattoo ink