New research points to potentially harmful chemicals in tattoo ink
New research presented at the fall meeting of the American Chemical Society has raised concerns that many tattoo inks contain chemicals that may be damaging to human health. Analyzing nearly 100 currently used tattoo inks the researchers found many inks contained chemicals not declared on their ingredient list, and at nanoparticle sizes suspected to be harmful.
“The idea for this project initially came about because I was interested in what happens when laser light is used to remove tattoos,” explained John Swierk, principal investigator on the new research from Binghamton University. “But then I realized that very little is actually known about the composition of tattoo inks, so we started analyzing popular brands.”
In the United States tattoos fall within the confines of cosmetics, according to the Food and Drug Administration (FDA). This means the inks being used do not need to be approved by the FDA and no regulations require a manufacturer to even list the ingredients in tattoo ink.
As Swierk and his colleagues started to investigate they quickly learned most tattoo artists didn’t know exactly what was in the inks they were using. And many companies manufacturing the inks were also found to produce pigments for paints and textiles. So were tattoo pigments using the same chemicals found in commercial paint?
Using techniques such as nuclear magnetic resonance spectroscopy and Raman spectroscopy the researchers set out to understand what exactly was in these tattoo inks. This preliminary phase of the research looked at around 100 tattoo inks, and according to Swierk there were surprises with almost every ink they studied.
“Every time we looked at one of the inks, we found something that gave me pause,” Swierk says. “For example, 23 of 56 different inks analyzed to date suggest an azo-containing dye is present.”
Azo dyes are generally considered to be safe, and are used in a number of commercial products from carpets to textiles. Some kinds of azo dyes are also used in food products. However, UV light or bacteria can cause these pigments to degrade into molecules that are known to be carcinogenic.
A further analysis of 16 inks revealed around half of the products contained nanoparticles smaller than 100 nanometers. Particles this small are much more likely to migrate to other parts of the body, as shown in a 2017 study finding tiny nanoparticles from tattoo ink can be found in a person’s lymph nodes.
“That’s a concerning size range,” added Swierk. “Particles of this size can get through the cell membrane and potentially cause harm.”
Ultimately, this work is still in its early stages. The researchers have set up a website called "What’s In My Ink," designed to catalog the contents of many commercially available tattoo inks. So far only a small number of inks are listed on the website. Once this latest data has been peer-reviewed and published in the journal it will be added to the website.