Each of the compounds that you tests contained chlorine, which is a poisonous gas. Why was this test safe to perform (it was, or your lungs would have turned to mush) without a gas mask?

I think it was safe to perform the test without a gas mask because the chlorine is bonded to another atom and in this case chlorine's properties are altered where it's toxicity is lowered. Also, the chlorine compound in this case most likely is in it's liquid form that lowers the danger of such substance. Hope this answers the question.