Does brass that is exempt from the lead-free drinking-water rule still need a Proposition 65 lead warning?

Is Proposition 65 the same thing as the federal lead-free rule?

No. The federal rule limits lead in drinking-water plumbing products, while Proposition 65 is a California law that requires a warning, or a change to the product, when it exposes people to a listed chemical such as lead.

The federal rule is a product definition: a weighted average of 0.25 percent lead on wetted surfaces, with exemptions for nonpotable and named products, per 42 U.S.C. 300g-6. Our guide to the federal exemptions covers which parts fall outside it. Nothing in that exemption speaks to California’s separate warning law.

Proposition 65 works differently. The California Attorney General’s Proposition 65 page gives its formal name, the Safe Drinking Water and Toxic Enforcement Act of 1986, and refers to its warning requirement in Health and Safety Code section 25249.6. The same page says a private party suing in the public interest must notify the Attorney General of the lawsuit and its outcome, and the page describes electronic filing of 60-day notices, settlements and judgments. A settlement binds its own parties and sets terms only for the products it names.

A 2011 judgment over brass hose products is a useful reminder. It defines its covered products as brass accessories, connectors, fittings and fasteners that are not the subject of California Health and Safety Code section 116875, the state’s own rule for brass plumbing pipes and fittings, and it draws no inference about those excluded products (2011 consent judgment). The warning regime and the drinking-water regime have always been treated as distinct.

What does that mean on a drawing and a mill certificate?

A drawing can state the alloy and a lead limit, and a mill certificate can report the bar chemistry, but neither says anything about lead on the finished surface. If a buyer needs the surface result, it has to be a separate test on the finished part.

The alloy test in the 2026 document is on the bar: no intentionally added lead and no more than 0.009 percent by weight, analyzed by EPA 3050B and 6020A or equivalent (see the judgment text). To check that on a certificate, the lead line must report a value at a resolution fine enough to sit against 90 ppm. A report that gives lead only as the alloy specification maximum, or in coarse steps, cannot show it. The 2011 judgment asks for the same discipline: it treats a test result as good-faith evidence when the method can quantify below its own 300 ppm threshold (see the 2011 text).

The surface test is different in kind. It is sampled with a named protocol, NIOSH 9100, over the entire surface area of the product. That result reflects what the finished part carries after machining, cleaning, any plating and handling, so a clean bar does not guarantee it. This is our reading of the document, not a statement about how any laboratory or court would treat a given part.

A drawing note that fits this is short: the alloy by ASTM designation and UNS number, the words “no intentionally added lead”, and the lead limit that the buyer has chosen to meet, each with the test method named. Drawings should not copy a limit from a settlement unless the buyer’s counsel has decided it applies to that product.

Who carries the warning duty when a supplier makes the part?

In the 2026 document the warning duty sits with the defendant that sells the products into California, which must also tell downstream customers what the warning needs to say. A turning supplier is not a party to it, but is the one asked for the alloy and test evidence.

The 2026 judgment requires the defendant to supply warnings with products sold to California customers and, for third-party websites it does not control, to tell downstream customers that the products must be accompanied by a warning, per the text of the judgment. It also states that products already in the stream of commerce before the effective date are treated differently. That shows how a duty passes down a distribution chain: by notice from the party that is bound.

For a buyer who sources machined brass parts from Vietnam or anywhere else, the working consequence is documentation. The product owner decides whether the part will ship with a warning, in a reformulated version, or not at all into California, and then needs the supplier to hold the alloy fixed and report it by lot.