For purposes of the Act, the weighted average lead content of a pipe, pipe fitting, plumbing fitting, or fixture is calculated by using the following statutory formula:
• For each wetted component, the percentage of lead in the component is multiplied by the ratio of the wetted surface area of that component to the total wetted surface area of the entire product to arrive at the weighted percentage of lead of the component.
• The weighted percentage of lead of each wetted component is added together, and the sum of these weighted percentages constitute the weighted average lead content of the product. The lead content of the material used to produce wetted components is used to determine compliance.
• For lead content of materials that are provided as a range, the maximum content of the range must be used.