Remove drycleaning from the plastic wrapping as soon as you get it and air it out for at least an hour. A toxin almost all drycleaners use is a substance called perchloroethylene, and its really not something you want in your body.~ Magazine Excerpt
This goes for new clothing. Most new clothing have been treated with chemicals, but don’t bother about washing them before you use them first. New clothing have treatments that are oil-based chemicals(as in unless you use scaling water (120+celcius) or soaked in hot sugar soap, they aren’t going to come off). Quite a few other chemicals also react with sunlight so put them on the outdoor clothes line for an hour or so and should be ready to wear without a wash.