Good info, but want to add something.
If chloroform starts to chemically decompose, you will notice the odor of freshly cut hay.
Phosgene smells like musty hay, or freshly cut grass. It's very hard to overestimate how dangerous phosgene is. It's used as a chemical weapon for a reason, as it's highly dangerous to the lungs, eyes, and skin.
It causes your lungs to fill up with fluid, and eats away at them like acid. This reaction can take days to set in, so feeling fine after exposure means nothing.
Before using chloroform, I'd want to figure out a way to test it...perhaps on mice in an aquarium.
Directions for using chloroform properly in surgical procedures can be found in the Special Forces Medical Handbook, which is available from Paladin Press and Desert Publications.