Section 143.12 - Definition of lead free and calculation methodology(a) "Lead free" for the purposes of this subpart means:(1) Not containing more than 0.2 percent lead when used with respect to solder and flux; and(2) Not more than a weighted average of 0.25 percent lead when used with respect to the wetted surfaces of pipes, pipe fittings, plumbing fittings, and fixtures.(b) The weighted average lead content of a pipe, pipe fitting, plumbing fitting, or fixture is calculated by using the following 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 constitutes the weighted average lead content of the product. The lead content of the material used to produce wetted components is used to determine compliance with paragraph (a)(2) of this section. For lead content of materials that are provided as a range, the maximum content of the range must be used.(c) If a coating, as defined in § 143.11 , is applied to the internal surfaces of a pipe, fitting or fixture component, the maximum lead content of both the coating and the alloy must be used to calculate the lead content of the component.(d) If a liner, as defined in § 143.11 , is manufactured into a pipe, fitting or fixture, the maximum lead content of the liner must be used to calculate the lead content of the component.(e) If a fixture contains any media (e.g., activated carbon, ion exchange resin) contained in filters, the media are not to be used in determining the "total wetted surface area of the entire product" in paragraph (b) of this section.(f) In addition to the definitions of "lead free" in paragraphs (a) through (e) of this section, no drinking water cooler, which contains any solder, flux, or storage tank interior surface, which may come into contact with drinking water, is lead free if the solder, flux, or storage tank interior surface contains more than 0.2 percent lead. Drinking water coolers must be manufactured such that each individual part or component that may come in contact with drinking water shall not contain more than 8 percent lead while still meeting the maximum 0.25 percent weighted average lead content of the wetted surfaces of the entire product.