Ultraviolet (UV) systems are commonly used to provide disinfection in high-purity water systems used in pharmaceutical, biotech and diagnostic facilities, and research laboratories.
The requirements for high-purity water used in pharmaceutical systems are governed by the U.S. Pharmacopeial Convention (USP) and enforced by the U.S. Food and Drug Administration (FDA). The requirements for Clinical Lab Reagent Water (CLRW), used in diagnostic facilities, is regulated by the Clinical Lab Standards Institute (CLSI).
With a liberal USP and CLRW TOC specification of 500 parts per billion (ppb), the UV reactors in these high-purity water systems normally use “ozone-free” UV lamps that do not generate any UV wavelengths below 200 nanometer (nm), which means that they are usually assumed to have little effect on organic contaminants and are mainly intended for bacterial control.
It has been observed, however, that high-purity water systems incorporating highly reflective UV reactors with ozone-free lamps are showing a significant reduction in total organic carbon (TOC) levels, compared to conventional UV systems.