DRINKING WATER treatment products fall into three main groups, each with a distinguishing NSF Mark: water treatment systems, replacement elements, and components.

Complete DWTU Systems
An NSF-Certified complete water treatment system will display the Mark on the product data plate and its packaging, citing the standard(s) and reduction claims for which it is certified. The data plate is a permanent label affixed to the system that provides critical information such as model number, certified claims, replacement element, flow rate, working pressure, and capacity.

Replacement Elements
Replacement elements must have the NSF Mark on the replacement packaging but cannot display the Mark on the element itself. The packaging must specify the standard the element was tested against, the model it was tested in, and the reduction claims for which the the system is certified.

Replacement elements are tested and certified to fit specific filtration systems. If a replacement element is used in a different system than the one it was tested in, certification of the replacement element is lost. When inspecting a water filtration unit, make sure the replacement element is being used in the same system it was originally certified for.

Components
Components certified to an ANSI/NSF DWTU Standard must bear the mark on the product packaging but cannot display the Mark on the product itself. This is to ensure that a certified component cannot be installed and misrepresent the entire system as NSF Certified.

The component Mark includes the word COMPONENT and a boxed statement that tells what part of the standard it was certified against. All components are tested for material safety. Pressure-bearing components are also evaluated for structural integrity.

Look for the NSF Mark on all water filtration products. When in doubt, contact NSF International at 1-800-NSF-MARK or visit www.nsf.org for daily updates of all NSF-Certified products.