It really comes down to the ink you use.
The primary ingredients in most printer inks are water, ethylene glycol and alcohol. Printer ink is about as safe as dish washing soap. Drinking it can make you sick, but it is not life threatening. If you have questions about the toxicity of a particular brand of ink, all companies publish Material Safety Data Sheets for their products. These are usually available on their websites and they will tell you what the ink contains. Inks used in commercial printing processes however, may contain toxic metals.