just my thoughts, how deep are you cutting?
and on the coolant, i'm using koolmist77 mixed at double the suggested mix rate, (if the instructions said 4oz for a gallon of water i put 8) and i cant detect any odor in my cnc room, its a 8x10 room in my shop, not air tight, but i would smell anything foul... so far i'm ver impressed with it, cuts well, cleans up easy, and i dont have any rust on my machine. ofcourse i'm only working in alum right now...but there is some steel in my future...
Grizzly X3, CNC Fusion Ballscrew kit, 3 500oz-in bipolar steppers, 3 203v Gecko's, Linear power supply from Hubbard CNC, Mach 3, BOBcad Pro Art V22, Rhino.