Guide
How should lead-free and NSF marks be applied to small machined water parts when there is no room for them?
Lead-free and NSF marks are the registered trademarks of third-party certification bodies, usually paired with identifier text naming a test standard, that show a drinking-water product has been tested to the lead-free requirement. General information, not legal advice: this guide covers how the marks are placed and written on a drawing, and it leaves the question of which standard a product needs to its manufacturer and the certification body.
By Saola Manufacturing engineering team · Published · Updated
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Where do lead-free marks normally go on a product?
According to the EPA guide, the certifier's mark is typically on the front or back of the packaging or engraved on the product itself, with identifier text placed to its left, right, above or below. The mark is the certification body's registered trademark, so it is applied to the artwork the body approves.
The same EPA guide counts eight ANSI-accredited third-party certification bodies for the lead-free requirement: ALS Global, CSA Group, IAPMO R&T, ICC-ES, Intertek, NSF, UL Solutions and WQA. Each has its own marks and its own identifier text rules, and the guide includes photographs of an engraved mark on a product and of marks on packaging.
For a machined part this means the mark is not something a drawing invents. The brand owner chooses the certification body, receives approved artwork and marking rules from it, and passes those to the supplier; the supplier's task is to apply them as written.
How do you read the identifier text next to a mark?
The identifier text names the standard the product was tested to: NSF/ANSI/CAN 372 means lead content, and NSF/ANSI/CAN 61 also means leachate testing. A mark on a part with only the 61 text can still be fully compliant, so the listing is the proof, not the text alone.
The EPA guide explains that since October 2017 NSF/ANSI/CAN 61 has required compliance with 372 for products that are not exempted, while earlier products may show 61-G or Annex G, a retired predecessor. Some certification bodies still require the 372 text on the product. If a product shows only the 61 text, the guide recommends checking the data sheet or the certification body's online listing directory.
For drawing purposes the useful rule is to copy the identifier text exactly as the certification body gives it, and never to shorten it to fit a small face.
| Identifier text | What it indicates | Note from the EPA guide |
|---|---|---|
| NSF/ANSI/CAN 372 | Meets the weighted average lead limit of 0.25 percent on wetted surfaces | Lead content only; solder and flux are held to a lower limit |
| NSF/ANSI/CAN 61 | Meets the lead limit and the leachate requirements for contaminants | Includes 372 compliance for non-exempt products since October 2017 |
| NSF/ANSI/CAN 61 and 372 | Both of the above | Some certification bodies still require the 372 text |
| NSF/ANSI 61-G or Annex G | Lead-content check of the retired annex | May still appear on older products; included with 61 |
| LLC or Low Lead Content (CSA Group) | Signifies compliance with NSF/ANSI/CAN 372 | Certifier-specific wording |
| Text-only mark (ALS Global) | Used for products with size or design limitation | Certifier-specific; ask the body |
What if the part is too small to carry a mark?
The EPA guide notes that some products and packaging may not bear the mark for reasons that include lack of space on small packaging or parts, and that contacting the manufacturer is then the best way to confirm lead-free status. For a stem or nozzle, the proof moves to the carton, the label, the data sheet and the listing.
Do not shrink the mark until it cannot be read. Each certification body sets its own rules for what may appear and in what form, and the EPA table shows one body with a text-only mark for products with size or design limitations. That is a certifier-specific option, so the right question for the brand owner is whether the body allows a text-only mark, a mark on the individual bag or carton, or marking on the assembly that the part goes into.
Small turned parts such as stems, nozzles and small fittings are the usual case. A reasonable plan is to put the identifier on the packaging and the paperwork, keep traceability on the part by lot, and leave the engraved mark to the larger parts of the assembly. The guide on lead-free brass for NSF 61 and 372 covers the alloy side and who holds the certification when parts are made overseas.
Who holds the listing, the brand owner or the machine shop?
EPA requires manufacturers or importers to certify that their products meet the lead-free requirement, and the listing names a manufacturer and a manufacturing facility. In the common arrangement the brand that sells the finished product holds the listing, and the machine shop supplies parts to the listed material and drawing.
The EPA questions and answers on the final rule states that EPA is requiring that manufacturers or importers certify that their products meet the new requirements. The NSF listing page for NSF/ANSI/CAN 372 shows what a listing contains: the manufacturer name and address, the manufacturing facility, the product category and model, and footnotes that limit size ranges or configurations.
This is general information, not legal advice, and the arrangement varies by product. A turned stem sold alone as a spare is a product of its own; a stem built into a valve is usually covered by the valve's listing. Settle which case applies in the supply agreement, and ask the certification body two questions before production moves: whether the listing names the facility that machines the part, and whether adding a facility needs an update.
A machine shop must never apply a mark it has not been authorized to use. The mark is a trademark of the certification body, which is another reason the brand owner supplies the approved artwork.
What should a drawing note for marking say?
Say what is marked, where, by which method and from which approved artwork, and state that no mark may touch a sealing surface or thread. A marking note without an artwork reference invites a supplier to improvise the mark.
A workable pair of notes follows. For the part: "Mark [brand-supplied text or artwork, revision] on [named non-sealing face] by [engraving or other method named by the brand]; legibility to be confirmed on the first article; no marking on sealing surfaces, threads or wetted bores." For the packaging: "Individual bag or carton label to carry the certification body's mark and identifier text from approved artwork revision [letter]; label to be checked at packing."
Keep four rules in the note. Name the artwork and its revision, so there is a reference to check against. Name the face, so the mark does not land on a seal land or a thread. Name the method and who approves it, because laser or other engraving may be done through a partner plant Saola manages, outside the turning step, and each quote states the production site. State what happens when the face is too small: either the packaging carries the mark or the brand owner decides.
The turning itself is routine work at the lead plant; see CNC turning for the part families it covers. If a lot is later found with missing marks, treat it as a nonconformance against the note, as described in the guide on non-conformance reports.
How do you check a lead-free listing before you accept the parts?
Open the certification body's product directory and match the company, the manufacturing facility, the product and the size range against your purchase order. The NSF page itself advises contacting NSF to confirm the status of any listing.
The EPA guide gives the directory address for each of the eight certification bodies, and the NSF listing page describes what to look for: the manufacturer and facility, the product or model, and the footnotes. It also uses symbols to flag lead-content status; for example, a [G] symbol means the product meets NSF/ANSI/CAN 372, and an [LL] symbol marks products meeting the lead-free definitions of several states and of the federal act. The page says that the mark must appear on the product, its packaging or its documentation, and it carries a fraud alert advising readers to check text against NSF's official link.
A practical acceptance routine has four lines. Match the part number or family to a listing entry. Match the machining facility to the facility on the listing. Check that the size range and configuration fall inside the footnote. Record the listing date and the lot with the incoming inspection. The guide on incoming inspection of machined parts shows how to fold that record into a normal receiving check.
Frequently asked
Does a lead-free mark have to be engraved on the part?
No. The EPA guide says the mark is typically on the packaging or engraved on the product, and that some products and packaging may not bear it for lack of space. The listing, the label and the documents then carry the proof.
Can a machine shop add the NSF mark to a part it makes?
Not on its own authority. The mark is a registered trademark of the certification body, so the brand owner supplies approved artwork and the supplier applies it as written.
What does 61-G or Annex G on an old part mean?
The EPA guide describes Annex G as retired, with the text still found on some products; it indicated the lead-free requirement and is listed together with NSF/ANSI/CAN 61.
Is a mark enough to prove a part is compliant?
The mark and identifier text are the first sign, but the EPA guide recommends checking the data sheet or the certification body's directory when only the 61 text appears. The listing is the proof.
Where do I check that a supplier's plant is covered?
In the certification body's listing, which names the manufacturer and the manufacturing facility. If the machining plant is not named, ask the brand owner and the certification body before you order.
Sources
- How to Identify Lead Free Certification Marks for Pipes, Fittings, Fixtures, Solder, and Flux (EPA/600/F-13/153d), US EPA, revised June 2024
- NSF/ANSI/CAN 372, drinking water system components, lead content listings, NSF International, accessed October 2026
- Questions and answers about the final lead free rule, US EPA, accessed October 2026
- 42 U.S.C. 300g-6, prohibition on use of lead pipes, solder and flux, Legal Information Institute, Cornell Law School, accessed October 2026