Chemical specification of Drinking Water, for applications such as some initial rinsing operations and active pharmaceutical ingredient manufacturing operations, must meet the U.S. Environmental Protection Agency’s (EPA) National Primary Drinking Water Regulations (NPDWR), or comparable regulations of the European Union, Japan, and/or World Health Organization, as applicable, for Drinking Water. It is important to note that the NPDWR will change with time, incorporating additional parameters or changing regulated item concentrations. It should be emphasized that all validated USP systems, as well as systems using Drinking Water, should have access to correspondence identifying changes to these regulations.
It is highly recommended that supplemental analysis for Drinking Water, including feed water to a USP Purified Water or USP Water for Injection system, be considered. The nature and type of analyses are dictated by the intended use of the Drinking Water. For example, if groundwater is used for an initial rinsing step during applications such as clean-in-place (CIP) or the production of an active pharmaceutical ingredient, it may be appropriate to treat the water through a particulate removal filter and/or water softening system. If water softening is used, the presence of high molecular weight multivalent cations, such as barium, strontium, and aluminium, in the feed water should be identified. these compounds will affect the Standard Operating Procedures (SOPs), specifically the regeneration salt dosing and concentration, during regeneration of the water softening system. Multivalent cations, such as calcium and magnesium, are not included in the NPDWR, but affect the performance of the system.
Other specific components are critical to different water purification unit operations. Another example is the level of naturally occurring organic material (NOM) in a surface water supply to a USP Purified Water system. Both anion resin and reverse osmosis (RO) membranes will foul due to organic material. The level of the NOM in feed water will not only dictate the nature of pre-treatment equipment but also establish an analytical monitoring program clearly demonstrating that the selected pre-treatment operations protect the anion resin within the ion exchange system or RO membranes from fouling.