Icynene. The company’s new LD-R-50 spray-foam insulation has earned the U.S. Department of Agriculture’s BioPreferred status for use of rapidly renewable materials. The insulation is made using castor oil, a natural product that is extracted from the castor plant. The product is water-blown and free of HFCs and PBDEs. 800.758.7325. www.icynene.com.