Natural fiber blankets are usually made from cotton, cotton/linen, cotton/silk, wool, alpaca, cashmere, angora or various natural fiber blends. Newly developed are blankets made from corn. Many natural fiber blankets now come from organic sources. They are gorgeous, durable and considered healthier than conventional blankets which are commonly acrylic or polyester fleece.

Arylic is made from acrylonitrile (a petroleum product) and can emit petrochemical odors. Acrylic in consumer products is generally well tolerated by most people, although the chemically sensitive person may not be able to tolerate it, especially when breathing it all night long from their bed covers. OSHA and NIOSH regulate acrylonitrile in the workplace and the U.S. Agency for Toxic Substances and Disease Registry claims that exposure at high concentrations can cause minor to severe symptoms and there is evidence that children are more sensitive to it than adults. We are not aware of any studies that have been performed on long term exposure at low concentrations.
Just as with sheets, conventionally produced natural fiber bed linens can have chemicals applied throughout the process with dyes and fixatives which could contain heavy metals or other toxins.
Organic cotton or Green cotton blankets, unbleached and untreated, are very popular. Cotton blankets are washable and generally preferable for those with breathing allergies or asthma. They are usually lightweight and cost competitive. Flannel, knit, woven, thermal and chenille provide a great variety of choices. Blankets that are less fuzzy are preferable for those with breathing allergies or asthma because the tiny fibers that make up the fuzzy fabrics are less secure on the fabric and more easiy inhaled, which can irritate breathing pathways.
Wool blankets are also popular — plus they're warm and cozy. Most wool items do not attract or accumulate dustmites. Some wool blankets on the market are chemically treated for moths and some may have a "dry clean only" care label, both processes often bothersome to the chemically sensitive. We recommend alternative cleaning. You can request "wet cleaning" or perchloroethylene-free cleaning, and no moth-proofing at your dry cleaners. Still, be sure to air your blanket out before placing it on the bed again. If you're particularly sensitive, you may want to skip the cleaners and just vigorously shake out your wool blankets and air them outside, but be careful the colors don't fade in the sun.