Tattoo ink isn't regulated in the United States, and new research suggests it may contain potentially cancer-causing dyes, plus tiny particles that may cause harm. File Photo by Debbie Hill/UPI | License Photo
Aug. 24 (UPI) -- What's in tattoo inks is widely unknown because they aren't regulated in the United States, and new research suggests they may contain potentially cancer-causing dyes as well as tiny particles that may travel in the body and cause harm.
And tattoo removal also is worrisome because it isn't known how the ink breaks down or what products form when it does, researchers said.
Their findings were to be presented Wednesday at the fall meeting in Chicago of the American Chemical Society, which has produced a video on why tattoo inks are permanent.
After analyzing nearly 100 inks, the scientists concluded that even when these products include an ingredient label, the lists often aren't accurate, a news release said.
According to the researchers, tattoo inks contain a pigment and a carrier solution. The pigment may be a molecular compound, such as a blue pigment; a solid compound, such as titanium dioxide, which is white; or a combination of the two compound types, such as light blue ink, which contains the molecular blue pigment and titanium dioxide.
The carrier solution carries the pigment to the middle layer of skin and typically helps to make the pigment more soluble, scientists said. It also may control the viscosity, or thickness, of the ink solution, and sometimes includes an anti-inflammatory ingredient.
"Every time we looked at one of the inks, we found something that gave me pause," John Swierk, the project's principal investigator and assistant professor of chemistry at Binghamton University -- part of the State University of New York -- said in the release.
For example, 23 of 56 different inks analyzed to date suggest that an azo-containing dye is present, Swierk said. And while many azo pigments -- basically synthetic organic dyes -- don't cause health concerns when they're chemically intact, bacteria or ultraviolet light can degrade them into another nitrogen-based compound that's a potential carcinogen.
The team also analyzed 16 inks using electron microscopy, and about half contained particles smaller than 100 nanometers, which Swierk described as "a concerning size range" since they can pass through cell membranes and potentially cause harm.
The scientists said they plan to add the information to their website, What's in My Ink?, after they run additional tests and the data are peer-reviewed.
"With these data, we want consumers and artists to make informed decisions and understand how accurate the provided information is," Swierk said.
He said the idea for the project initially developed because of his interest in what happens when laser light is used to remove tattoos.
"But then I realized that very little is actually known about the composition of tattoo inks, so we started analyzing popular brands," he said in the release.
Swierk said he and his team interviewed tattoo artists to see what they knew about the inks they use on customers. And while the artists could quickly identify a preferred brand, they didn't know much about its contents.
"Surprisingly, no dye shop makes pigment specific for tattoo ink," Swierk said. "Big companies manufacture pigments for everything, such as paint and textiles. These same pigments are used in tattoo inks."
Swierk noted that while tattoo artists must be licensed for safety reasons, no federal or local agency regulates the contents of the inks.
His conference presentation was to focus on work being done to separate the different components in tattoo pigments and identify them through different analytical techniques, such as Raman spectroscopy, nuclear magnetic resonance spectroscopy and electron microscopy.
These analyses confirmed the presence of ingredients not listed on some labels, the researchers said. For example, in one case ethanol was not listed, but chemical analysis showed it was present in the ink. The team also has been able to identify the specific pigments found in some inks.
Swierk's university webpage describes how his lab is involved in a National Institutes of Health-funded effort focused on the safety and photochemistry of tattoo inks.
"Despite the popularity of tattoos and the billions of dollars spent every year on laser tattoo removal, we do not understand how tattoo inks transform under illumination and what risks that may pose to human health," the chemistry lab's site says.
The lab's multipronged approach draws from analytical chemistry, materials science, and cell biology to address the simple question, "How do tattoos fade?" the site says.