Is it actually dangerous to write on your hand (or any skin for that matter)?
After attempting to research all types of inks in all types of pens, I have come to the conclusion that this is a subject of overwhelming breadth. There are cheap pens and expensive pens. Ballpoints, gel, fountain, and permanent. Oil or water based?
All of these details play a factor in the formula of the ink used, which turns out to be pretty important. For instance, a blue gel pen uses a chemical called copper phthalocyanine (I’m glad this is written and I won’t have to try to pronounce that). Its Material Safety Data Sheet (MSDS) states that it is “hazardous in case of skin contact.” I think that’s straightforward enough.
But wait, that’s just the pigment. What about the solvent? It’s the component of the ink that makes sure all the ingredients stay together and you don’t get one liquid flowing out before another. Gel pens use a solvent called ethylene glycol. Its MSDS is even freakier than copper phthalocyanine’s. Even though its carcinogenic (cancer causing) effects aren’t classifiable for human or animals, its mutagenic effects sure are. And wait, there’s more! They’re specifically mutagenic for mammal’s body cells.
So let’s say you’ve just read this and thought, “OK, I’m safe. I only write on myself with a ballpoint pen. Gel pens are for elementary school kids.” Well, first off, you just doomed children to a scary, mutagenic future without a second thought. Second, ballpoint pens aren’t the best either. They use propylene glycol as a solvent. In case of contact with skin, the MSDS sheet warns the user to “immediately flush skin with plenty of water… get medical attention.”
Sharpies are the worst offenders of all. Because they use dyes instead of pigments, they need really fast evaporating solvents to ensure that they don’t waste too much ink. Which translates into solvents that enter very quickly into your bloodstream. And Sharpie has their very own MSDS!
Sharpies use three kinds of solvents: propanol, butanol, and diacetone alcohol. Notice how they all end in “ol”? That means they’re all some form of alcohol and therefore all potentially combustible. But definitely not drinkable.
Propanol, if inhaled, can cause drowsiness or dizziness. Butanol is classified as “very harmful” if in contact with the skin or inhaled. Diacetone alcohol is toxic to the lungs and is a skin irritant.
Wrapping it up: there seems to be a harsh ingredient in each pen’s ink formula. This guru’s suggestion? Buy a date-book or planner, or keep events saved in your cell phone. It’s not worth the risk, or looking silly when you fall asleep with the back of your hand against your cheek.