California Code, Public Resources Code - PRC § 42891

The Department of General Services shall revise its procedures and procurement specifications for state purchases of products that are made of, or contain components that can be derived from the recycling of, used tires, including, but not limited to, rubber, oil, natural gas, carbon black, asphalt rubber, floor tiles, carpet underlays, mats, drainage pipes, garbage cans, retreaded tires, and water hoses. For those purchases, the department shall give preference, wherever feasible, to the suppliers of recycled tire products. This preference shall be 5 percent of the lowest bid or price quoted by suppliers offering similar products made from nonrecycled components.