Quantitative methods for the risk assessment of drinking water contact chemicals following the NSF/ANSI/CAN 600 standard – part I: general methods

Health-based criteria have been developed using quantitative methods for over 370 unregulated chemicals that have been detected in extraction testing of products certified or undergoing certification to public health-based drinking water standards. These criteria are derived in accordance with the requirements of NSF/ANSI/CAN 600, <i>Health Effects Evaluation and Criteria for Chemicals in Drinking Water</i> and undergo external peer review by an independent Health Advisory Board. However, a complete and unified description of how these criteria are derived is not available in the scientific literature. This is the first part of a two-part publication that describes the core concepts involved in deriving these criteria. In this first part, general approaches that are consistently applied to the derivation of health-based criteria are discussed, including methods related to the literature search, evaluation of study quality, derivation of the reference dose, selection of uncertainty factors, and identification of the appropriate drinking water intake rate.