as safe as cutting your finger while cooking :)
the only risk is the risk of infection from the open wound (since it's lots of needle pricks in the skin, they are open wounds)
If you have never had one before, be wary of red color. generally anything red you want to do an allergy test for just to make sure you don't have an allergic reaction. Red is one of those odd ones that people have reactions to. If you have never had issues with red dyes though, such as red40 in your food etc, you should be fine without having the test. the test consists of them doing a small dot (where the tatt would be so that it gets covered up if you don't react) then wait 24 hours to see if a reaction occurs.
but really, that allergy test is not required as I said, if you don't react to food with red40, you'll be fine with a red tatt.
at 9:18 PM on Feb. 10, 2009