Crumb rubber means rubber granules derived from waste tires that are less than or equal to one-quarter ( 1/4) inch (6mm) in size. "Crumbing" in reference to waste tires means action which produces crumb rubber.
Cal. Code Regs. Tit. 14, § 17225.720
Note: Authority cited: Sections 40502, 42820, 42830 and 43020, Public Resources Code. Reference: Sections 42800, 42801.7, 42820, 42830 and 43020, Public Resources Code.