NSF/ANSI/CAN 60 — Drinking Water Treatment Chemicals: Health Effects — is the standard that answers one question: when a treatment chemical is dosed into drinking water at its maximum use level, do the contaminants it contributes stay below levels considered safe for lifetime consumption? It is a health-effects standard, not a performance or quality grade, and in many jurisdictions a current listing to it is a condition for using a chemical in potable water treatment. This article explains what the standard covers, how products are evaluated, what a maximum use level actually means for procurement, and how a buyer verifies a supplier's listing.
What the standard covers — and what it does not
The standard applies to chemicals added to drinking water on purpose: coagulants such as ferric chloride and polyaluminium chloride, disinfectants such as sodium hypochlorite, pH adjusters such as sodium hydroxide and sulfuric acid, corrosion and scale control chemicals, and polymers used as flocculant aids. What it evaluates is the contribution of contaminants — not performance. A listing says nothing about how well a coagulant will clarify your water, what dose you will need, or how the product handles; those remain engineering questions settled by jar testing and plant trials. Nor is it a general workplace-safety mark: handling hazards are addressed by the product's SDS, not by the listing.
How a product is evaluated
Evaluation starts with full disclosure: the manufacturer submits the product formulation, every raw material and its source, and the manufacturing process. Toxicologists identify which contaminants could plausibly be present — for a mineral coagulant, chiefly trace heavy metals arriving with the raw materials. Laboratory testing then doses the product into test water at its maximum use level and measures what actually ends up in the water. Each contaminant is compared against a maximum allowable level derived from drinking water limits such as EPA maximum contaminant levels and WHO guideline values, typically applying an allocation factor of around 10% so that a single treatment chemical cannot consume the entire allowance. Listing is maintained through periodic retesting and facility audits, and changes in formulation or raw material sourcing trigger re-evaluation.
Maximum use level: the number that matters
Every listing carries a maximum use level (MUL) — the highest dose, in mg/L of product, at which the health-effects evaluation was performed. Dosing above the MUL takes the application outside the evaluated envelope, so the listing no longer supports it. That makes the MUL a genuine procurement parameter: your intended maximum dose, including worst-case raw water events, must fit under the listed MUL of the specific product you buy. In CHIMI ART's case, our ferric chloride is listed under NSF/ANSI/CAN 60 with a listed maximum use level of 100 mg/L. Typical clarification doses for surface water sit well below such ceilings, but the working dose for any specific water is set by jar testing, not by the listing.
What testing focuses on for coagulants
- Trace heavy metals in the mineral raw materials — arsenic, lead, mercury, cadmium, and chromium are the recurring names
- Process contaminants introduced during manufacturing
- Unreacted monomer content in polymer products — acrylamide in polyacrylamide flocculants is the classic case
- Anything formulation-specific that the toxicological review flags for the product's chemistry
How to verify a supplier's listing
- Search the official NSF listing directory by company name — do not rely on a logo printed in a brochure
- Match the trade name and the production facility exactly; listings are product- and site-specific
- Check the listed maximum use level against your plant's intended maximum dose
- Require the current listing extract in tender submissions and keep it in the compliance file
- Re-verify at contract renewal or re-tender — listings can lapse or change scope
Common misconceptions
Three misunderstandings cause most procurement errors. First, a listing is not a performance claim — two listed coagulants can behave very differently on the same raw water, which is why jar testing remains the selection tool. Second, related quality marks are not interchangeable: food-grade labels, certificates of analysis, and quality-management-system approvals each say something real, but none of them is an NSF/ANSI/CAN 60 listing, and tender language should name the standard explicitly if that is what is required. Third, a listing belongs to a specific product from a specific production site — a chemically identical product from another source is not covered by someone else's listing.
Where the standard fits in procurement and dosing
For utilities and consultants, referencing NSF/ANSI/CAN 60 in a specification is a compact way to impose a vetted health-effects requirement without writing a toxicology annex, and many drinking water tenders in export markets do exactly that. For plants under local regulation, the standard complements national requirements rather than replacing them — always confirm with your health authority which approvals apply to your intake. A practical specification names the standard, requires a current listing for the offered product and its production site, and states the plant's maximum intended dose so compliance with the listed maximum use level can be checked line by line.
A listing sets the health-effects ceiling; jar testing sets the working dose. To evaluate a coagulant properly, run comparative jar tests on your own raw water across a realistic dose range, and confirm that the selected product and dose respect the listed maximum use level with margin. CHIMI ART's technical team can provide the listing documentation for our ferric chloride, support comparative jar testing, and help translate the results into a dosing specification — contact us with your water analysis to get started.