I have read recently that there is a question as to whether the chemicals in spray tan are safe to use, because you inhale a small amount when spraying. Is a mask enough to protect you from this?
The European Scientic Committee on Consumer Safety reviewed the safety of Dihydroxyacetone, the main active ingredient, in spray booths a couple of years back. Their review, which is here, concluded that based on current knowledge when used between 8 and 14% (typical concentration for these products) the ingredient would not pose a risk to consumer health.
I can recall a similar story recently (which I cant find), however the main concern was for workers that were applying the tans who are exposed to the sprays for several hours a day 5 days a week.