NSF ANSI CAN 372:2020 pdf free download – Drinking Water System Components – Lead Content
2 Definitions
2.1 coating: A covering or barrier applied to a substrate by electro, chemical deposition or via mechanical adhesion (paint).
2.2 liner: A barrier component which is mechanically attached and sealed to prevent water contact with another component. (Example: a tubular or cast brass spout with a thermoplastic sleeve inserted inside and sealed with an O-ring or other sealing material, such that water does not come into contact with the brass spout material.)
3 General requirements
Solders and fluxes shall have a lead content less than or equal to 0.2%. All other products shall have a weighted average lead content less than or equal to 0.25% based on the average of their wetted surface areas.
3.1 All components ≤ 0.25%
If each component of a product has a wetted surface with a lead content of not more than 0.25%, then the product is considered compliant and no further evaluation is required.
3.2 Any components > 0.25%
If any wetted components of a product have a surface area with a lead content of more than 0.25% lead,then the weighted average lead content shall be calculated according to Section 4 to determine compliance.
3.3 Restriction on the use of lead containing materials
There shall be no lead added as an intentional ingredient in any product, component, material, or their coatings submitted for evaluation to this standard with the exception of brass or bronze meeting the definition of “lead free” under the specific provisions of the Safe Drinking Water Act 5 of the United States.
4 Weighted average lead content calculation
The weighted average lead content of the product shall be calculated using the surface area and lead content information established under Section 4.1. For internal NPT (pipe) threads, engagement of male components into female threads will assume that 25% of the length of the female thread remains exposed as wetted surface area. All of the wetted surfaces are to be included in the weighted average lead content calculation, not just those surfaces that contain lead. The results of the weighted average lead calculation shall be rounded to two decimal places prior to determination of compliance.
5 Percentage lead content of water contact surfaces
The maximum lead content of the material specification used to produce wetted components shall be used to determine compliance with this standard. When the actual percent of lead in the chemical composition of individual components is to be determined, the procedures in Section 7 shall be followed.
5.1 Liners
When lead-bearing surfaces have been excluded from water contact by use of a rigid liner (e.g., plastic sleeve) sealed with a permanent barrier, the lead content of the liner shall be used.
5.2 Coatings
When coatings are used, the lead content of the coated substrate shall be used in the calculation of weighted average lead content.
5.3 Lead removal technologies
For components where the wetted surface areas have been treated with a lead removal technology, the percent lead composition shall be based on the material used to manufacture the component prior to application of the surface treatment.