Every material and product in a cold water service is chosen so that it is fit for its intended purpose (Appendix B explains how that is shown; in Australia the PCA and WaterMark govern products in contact with drinking water). In New Zealand, products touching water meant for drinking, food preparation, utensil washing or personal and oral hygiene must meet AS/NZS 4020, and linings and coatings must meet it at a surface-to-volume ratio no higher than the installation's.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.