Polyurethane spray foams are highly efficient insulators, but they’re made from petroleum. Some companies have turned to soybean oil as a substitute for nonrenewable fossil fuel. But Icynene has turned to a different seed to make their new, more sustainable LD-R-50 open-cell polyurethane: the castor bean. Castor-oil plants are easy on the environment—they require no irrigation, pesticides, or fungicides—and yield 23 percent more oil by weight than soybean plants. Yet the foam made from it is virtually indistinguishable in appearance and performance from Icnyene’s other foams.
About 42 cents per cubic inch installed; Icynene, Inc.