NSF P473: PFOA/PFOS protocol (now largely folded into NSF/ANSI 53)

NSF Protocol P473 covered PFOA and PFOS reduction. Those claims now appear under NSF/ANSI 53. In NSF's drinking water treatment listings we checked, PFOA/PFOS claims for the models we track appear under NSF/ANSI 53, and P473 shows up only in a footnote for Multipure's CBLX (Aqualuxe) cartridge. See PFOA/PFOS filters.

A product can be "certified" (listed by NSF or another accredited certifier) or merely "tested to" a standard by a lab. Only certification includes ongoing audits. We only mark a model certified when it appears on NSF's listing.