NOTE: Since this article was first written we’ve received several requests for clarification on the content of the piece. We’ve re-written the article and included additional information in the hopes of presenting an unbiased overview of this subject. Please feel free to submit comments. (Dated: Sept. 12, 2009)
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What Are Glow In The Dark Tattoos?

To answer that question we must first look at the two distinctly different “glow-in-the-dark” tattoo categories:

-Glow-in-the-Dark Tattoos That Require No Light Source
-UV Reactive Tattoos That Require Back Lighting

Glow-in-the-Dark Tattoos That Require No Light Source
These tattoos do just what the title says: they glow in the dark without the use of a light source. Tattoos that fall into this category use what’s called “self-phosphoring” or “everglow” tattoo ink. Tattoo ink containing phosphors should be avoided because phosphor is a known carcinogen (Fishbein: Potential Industrial Carcinogens and Mutagens). Additionally in order to make the phosphors more visible radioactive substances are added to the ink.

UV Reactive Tattoos That Require Back Lighting
There are now UV inks available that are made from fluorescent ink that do not contain phosphors.
These inks have had fluorescent pigment added to colorless tattoo ink. This in turn leads to glow-in-the-dark tattoos that are only visible under a blacklight.

So How Does a UV Reactive Tattoo Work?

Let’s examine the concept of a blacklight. If you turn on a blacklight bulb in a dark room, what you see from the bulb is a purplish glow. What you cannot see is the ultraviolet light that the bulb is also producing. Our eyes can only see visible light in the spectrum ranging from red through orange, yellow, green, blue and up to violet. Above violet is ultraviolet light, which we cannot see. A blacklight bulb produces UVA light. What you see glowing under a blacklight, whether it’s a fluorescent ink tattoo or an invisible hand stamp, are substances emitting visible light in response to the UVA radiation given off by a blacklight.

Are UV Reactive Tattoos Safe?

Since no studies have been performed on the long term effects of UV tattoos it’s unclear whether they’ll cause problems for the wearer. People that get UV reactive tattoos have been known to suffer from frequent itching, dermatitis, and puffiness. Some of these symptoms don’t show up until the tattoo is exposed to sunlight or until the tattoo is a few months or years old. However some people never experience adverse side effects.

When thinking about getting any kind of tattoo, it is important to know that the FDA has not approved any ink for use on humans. Like regular tattoo inks, phosphorescent and fluorescent tattoo pigments are not regulated or approved for use. Paul Howard, Ph.D, of the FDA’s Arkansas-based National Center for Toxicological Research (NCTR) says that “There have been no systematic studies of the safety of tattoo inks”. He and his team are just now beginning research on how body cells treat tattoo inks. When cells discover foreign matter, they send in a cellular version of a clean-up crew to try and destroy (metabolize) the foreign material. So cells may try to destroy the ink, just as they rid the body of bacteria and other foreign matter as a defense against infection. How this immune response affects the individual is an important question that needs to be researched. (FDA US Food and Drug Administration, 2009)

Are UV Reactive Tattoos Carcinogenic?

No studies have been done to determine whether there’s a link between UV reactive tattoo ink and cancer. Without knowing the chemical makeup of a particular UV reactive ink it’s hard to determine if it is carcinogenic.

Inks are usually a mixture of metallic salts, dyes and other additives, even though some manufacturers have switched to organic dyes. With sun exposure and scarring added as potential carcinoma risks, no one has been able to definitively say that any tattoo ink causes cancer. (Kluger, 2009)

Should I Get a UV Reactive Tattoo?

When deciding whether or not to get a UV reactive ink tattoo, one of the the most important factors to remember is that FDA has not approved any tattoo pigments for injection into the skin. Also, you should know that UV tattoos are more difficult and require greater skill to apply. Constant use of a blacklight to visualize the tattoo is required. Getting a UV tattoo may take longer than a standard tattoo because UV ink is usually thinner and more challenging to apply. With all that said, the overall application procedure is performed the same way as other tattoos.

Before getting a UV reactive tattoo you should consult with a qualified and trusted tattoo artist who has experience administering this type of tattoo. Ask him/her outright if the tattoo ink contains phosphors or “everglow”. Ask to see the list of ingredients contained in the UV ink so you can make sure it doesn’t contain phosphors. Also, ask the artist for references from people that have received UV reactive tattoos from him/her.

Rule of thumb: do your research so you know the risks and can make an informed decision.