New research finds unreliable labels and potentially concerning ingredients in many popular tattoo inks.
In the last decade, the number of Americans with at least one tattoo has grown nearly 50 percent, from 21 percent in 2012 to an estimated 30 percent, according to an Ipsos poll conducted in 2019. And the trend is even more popular in younger people — those under 55 are more than twice as likely to have a tattoo.
What may surprise some people is that although tattoo businesses are subject to stringent sanitation and health protocols, a key component — the ink used to create the body art — is unregulated in the United States. In many cases, that may not be an issue, but a new study shows that the lack of oversight has resulted in mislabeled and potentially concerning ingredients.
“I think right now our most important finding is just how unreliable the labeling is on tattoo inks,” says principle investigator John Swierk, PhD, assistant professor of chemistry at Binghamton University, State University of New York.
Although ink manufacturers aren’t required to report their ingredients in the United States, most do, says Dr. Swierk. “To date, we’ve found very few inks that are correctly and completely labeled. Some of the omissions probably aren’t that serious, but in other cases the reported pigments do not match what is in the bottle, and that’s more of a concern,” he says.
The researchers presented their results on August 24 at ACS Fall 2022, the fall meeting of the American Chemical Society (ACS), held in-person from August 21 to 25 with on-demand access available August 26 to September 9.
Tattoo Ink Contains the Same Pigments Found in Paint and Textiles
Investigators initially planned to study what happens when laser light is used for tattoo removal, but then soon realized that very little is known about the composition of tattoo inks and so began to analyze popular brands.
Swierk and undergraduates in his laboratory interviewed tattoo artists to see what they knew about the inks they use on their customers. Although the artists could quickly identify a brand they preferred, most weren’t familiar with the actual content of the ink.
“Surprisingly, no dye shop makes pigment specific for tattoo ink,” Swierk said in a release. “Big companies manufacture pigments for everything, such as paint and textiles. These same pigments are used in tattoo inks,” he said, adding that no federal or local agency regulates the contents of the inks themselves.
Some Ink Ingredients May Cause an Allergic Reaction
Tattoo inks contain two parts: a pigment and a carrier solution. Using a number of different techniques developed to analyze particle size and molecular composition, Swierk and his team confirmed the presence of ingredients that aren’t listed on some labels. For example, in one case ethanol was not listed, but the chemical analysis showed it was present in the ink. Ethanol can cause skin irritation or contact dermatitis in some people, according to research.
Some Ink Particles May Be Able to Get Through Cell Membrane
“Every time we looked at one of the inks, we found something that gave me pause,” said Swierk. “For example, 23 of 56 different inks analyzed to date suggest an azo-containing dye is present.” Although many azo pigments do not cause health concerns when they are chemically intact, bacteria or ultraviolet light can degrade them into another nitrogen-based compound that is a potential carcinogen, according to the Joint Research Centre, which provides independent scientific advice to the European Union.
Scientists also examined 16 ink samples using electron microscopy, and about half contained particles smaller than 100 nanometers. “That’s a concerning size range,” said Swierk. “Particles of this size can get through the cell membrane and potentially cause harm.”
Are Inks Harmful to Human Health? More Research Is Needed
The research is ongoing, and investigators have plans to have their research peer-reviewed once it’s complete. The findings will be available on What’s in My Ink?, a website designed to help consumers understand what risks may be associated with different tattoo inks. “With these data, we want consumers and artists to make informed decisions and understand how accurate the provided information is,” said Swierk.
Swierk emphasizes that these findings don’t mean that the inks are necessarily harmful to human health. “Outside of allergic reactions, at this point we don’t know what if any hazards the inks might pose,” he says.
It is clear that proper sterilization procedures and good aftercare of tattoos are important to help prevent infection after a tattoo, says Swierk. “It’s important to work with an artist who is following best practices for safe tattooing. Those artists are also usually plugged into the wider community and aware of what inks are causing problems or seem to be of low quality,” he says.
Health Risks of Tattoos
In addition to the possibility of infection, there are a few other things to consider before getting a tattoo. Penn Medicine encourages consumers to be aware of following potential risks:
- Cancer There isn’t evidence to show that tattoos cause skin cancer, but some experts believe that some ingredients in the ink may be linked to cancer. Black ink is a particular concern because it contains a high level of benzo(a)pyrene, which is listed as a carcinogen by the International Agency for Research on Cancer (IARC), according to the American Cancer Society.
- Allergic Reactions Some people can have allergic reactions to the dyes used in tattoos. If you have frequent allergic reactions, check with an allergist before getting a tattoo.
- Heptatitis Hepatitis can be spread through the sharing of needles. Make sure that the tattoo parlor or tattoo artist has a policy that includes wearing new gloves and using new, clean needles for every customer.
- MRI Complications Magnetic resonance imaging (MRI) scan is a test that creates images of the structures inside of the body by using a large magnet, radio waves, and a computer. Although it’s rare, there have been instances where people with tattoos have experienced complications from an MRI procedure, including redness, swelling, and first or second degree burns. Some inks used in tattoos (especially red ink) may interfere with the accuracy of MRIs some individuals.
