Also by using distilled water the filters on the machine last way longer. The savings in filter replacements more than pay for the cost of the distilled water. No mineral buildup to clean off either. But to answer your question, chlorinated tap water run through a steam machine will not create a toxic level of chlorine in the air. After all, they are also used for babies' rooms... I'm no Doctor, nor do I play one on TV, but I have used humidifiers and steam machines my entire life. I have used both warm and cool mist types, and distilled water is where its at. Keeps the machine running/looking like new with minimal maintenance.
92% of all statistics are made up on the spot.