Definitely you want to get a low-VOC carpet - VOC stands for Volatile Organic Compound and its nasty stuff - and most carpets continue to emit it for up to 7 years after you install it. It can cause allergies and all kinds of weird stuff.
So savvy carpet people have the answer - low-VOC carets and again, let Avalon Carpet and Tile show you their selection
Friends of mine who are looking to replace carpet in their offices really like Avalons Interface Flor, which are totally environmentally friendly carpet tiles that can be simply laid on the floor or glued. Check them out on Concord Pike or Kirkwood high or give me a call for more details