Poly(hexamethylenebiguanide) hydrochloride (PHMB)(CAS Reg. No. 32289-58-0) is exempt from the requirement of a tolerance for residues of the antimicrobial in or on all food commodities when the residues are the result of the lawful application of a food contact surface sanitizer containing PHMB at 550 parts per million (ppm).
40 C.F.R. §180.1280