Just to point out, ethylene glycol metabolises through alcohol dehydrogenase enzyme, and with regards to ethanol it acts as a competitive inhibitor. Such that yes, ethylene glycol is bad for you, however the antidote for ethylene glycol poisoning is....ethanol. Literally swamps out the EG.
EG is probably okay in a sealed chiller loop for say, making a floodded font, but be iffy using it for say, an immersion chiller loop or something. If you can get propylene glycol it's a better alternative. Also a good idea if you are using a glycol to chill, and it's not colored - color it. If for some reason your beer comes up bright red or blue, its a pretty good indicator somethings gone bad.. otherwise you have a clear liquid leaking into a mostly clear liquid..