Carpeting made from natural fibers is preferable to carpeting whose binders off-gas indoor air pollutants. There are several varieties of carpet made with recycled content. Most common is recycled “pop bottle,” or PET, carpet. Polyethylene terephthalate is what water bottles and soda bottles are made from. It has been an alternative to nylon for many years and is easily recycled into fabric and carpet fiber. While it is a recycled product, it still uses synthetic latex as a binder so it doesn’t enhance indoor air quality. Inexpensive, low-fiber-count carpets have been known to crush in high traffic areas like stairs and doorways.