If it looks like I'm trying to pick a fight... I'm not, I'm rarely that obvious.
There's nothing extremely alarming about the chemicals printer ink contains. Take the PGI-220 for example, a very common cartridge used in the home. It contains 5-10% Glycerine, same as the food additive, 5-10% Glycol, The MSDS (Material Data Safety Sheet) doesn't specify whether it's the non-toxic propylene sort, or the mildly toxic ethylene variety, Lactam 5-10% witch is a solvent and also shows up in antibiotics, and finally water (H2O). Some of these chemicals could be potentially harmful if some one was drinking directly from the cartridge but the amount that is printed on a piece of paper is is not really dangerous although inhaling, swallowing or getting it in your eyes can cause a long list of unpleasant -- but non-lethal -- symptoms. In fact the European Union doesn't classify this ink as dangerous. The law requires that ink manufacturers post Material Data Safety Sheets on each product that they sell, and you can find them online. If you want to find the MSDS for your cartridge here are some links to some major manufacturer's MSDS reports:
Brother - http://www.brother-usa.com/msds/
Panasonic (Select Material Data Sheet) - http://panasonic.com/business/office/support-downloads.asp
Check out InkFarm.com for cheap non-lethal Original and Re-manufactured printer ink and toner's. That's the only trustworthy site I can find cheap printer ink at.