"Rice hulls were chosen because they are readily available, consistent in composition and have a fast growing cycle," says Raicevich. Rice hulls are a byproduct of rice grain. It's estimated that 10,000 pounds of hulls will be used for the bracket in the first year. The hulls are bought from farms in Arkansas and are supplied in a composite made by RheTech (Whitmore Lake, MI)

Other natural fillers, such as kenaf and wood were studied, but rice hulls had several advantages including low moisture absorbtion and the lowest probability to require tool modifications.

Ten percent talc-filled polypropylene was previously used to make the part.

"We developed this resin specifically for Ford over the last three years, working with the automaker closely, including in all phases of material qualification," said David Preston, director of business development for RheTech.

Use of the rice hulls did not affect the weight or the cost of the component.

In another innovation related to sustainability, polypropylene used in the part consists of 25% recycled material.

Ford has been a leader in developing applications for renewable materials, including soybeans as a raw material for polyurethane foam used in car seats.

Other examples include:  

Recycled cotton: Used as carpet insulation and a sound absorber; every 2014 F-150 is said to contain enough recycled cotton to make the equivalent of 10 pairs of jeans.

Recycled carpet: Some F-150 trucks have cylinder head covers made with EcoLon, a nylon resin produced from 100% post-consumer recycled carpet.

Recycled tires: A thermoplastic material made from recycled tires and post-consumer recycled polypropylene is used to make shields and some underbody covers on F-150.

Recycled plastic soda pop and water bottles: A lightweight fiber derived from recycled plastic soda pop and water bottles is used in F-150 wheel liners and shields.

Recycled post-industrial plastics: Used in interior finish panels, including around radio and climate controls.