System is certified by NSF/ANSI Std. 42 & 53. Effectively filter VOC#, lead, rust, chlorine taste, odor, cysts, nominal particulate (Class I) and MTBE. Improved drinking water quality, minerals are still in water which are essential for our daily healthy life.# Can refer to NSF International website for the claim and 53 type of VOC (included TTHM-Trihalomethane)