Quantitative methods for the risk assessment of drinking water contact chemicals following the NSF/ANSI/CAN 600 Standard – Part II: advanced methods

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 second part of a two-part publication that describes specialized methods that may be applied in drinking water risk assessments conducted according to NSF/ANSI/CAN 600, depending on data availability and understanding of the mode of action. The specialized methods discussed herein include the use of data-derived extrapolation factors (including dosimetric adjustment factors and chemical-specific adjustment factors), inhalation-to-oral route extrapolation, the use of threshold versus non-threshold approaches in evaluating dose-response, study mortality adjustments, benchmark dose modeling, and carcinogen-specific approaches such as the use of the cancer slope factor and lifestage adjustment for cancer potency.