If the area is well ventilated, you have little to worry about. If you can smell the aromatic odors, it might be bad for the chickens respiration, so either use them outdoors or leave them outdoors for a while to off gas.
People use cedar chips indoors because it gives off a pleasant (to us) odor that hides the smell of rodent urine. It's not really good for any animal to have to inhale that all the time. Of course the ammonia is even more toxic and covering it up so you don't have to clean as often is a recipe for disaster with anything that breathes.
Take a big whiff of the air your birds live in. If you can't wait to get out of there, your birds feel the same way, maybe times 2, because their respiratory systems are even more sensitive than ours.