The landscape for supplements
Dietary supplements sit in a different regulatory position from baby food, and the heavy-metal picture reflects it. This page orients a brand to that landscape; it is not legal advice, and a brand should confirm its obligations with its own counsel and against the applicable authorities.
There is no federal numeric heavy-metal limit set specifically for dietary supplements. The FDA regulates supplements as a category of food, and its current good manufacturing practice requirements for supplements (21 CFR Part 111) oblige a manufacturer to establish identity, purity, strength, and composition controls, but they do not set numeric maximum levels for arsenic, cadmium, lead, or mercury. What fills that space is a consensus standard and an enforcement regime.
The USP consensus standard
The United States Pharmacopeia General Chapter <2232>, Elemental Contaminants in Dietary Supplements, is the recognized voluntary standard for the four elements of primary toxicological concern in finished supplements: arsenic, cadmium, lead, and mercury. It applies to products that label themselves as conforming to USP or NF standards, and it sets permitted-daily-exposure limits, from which a concentration limit for the finished dosage form is derived using the product’s maximum daily intake. The older USP Chapter <231> Heavy Metals, a colorimetric method, was withdrawn effective January 1, 2018, and replaced by the modern elemental-contaminant chapters, of which <2232> is the one specific to supplements. A brand that certifies or labels USP conformance is holding itself to that chapter whether or not any statute requires it.
Proposition 65 is the practical enforcement driver
For supplements sold into California, California Proposition 65 is the mechanism that most often turns a heavy-metal result into a legal event. It requires a clear warning before exposing a person to a listed chemical, including lead, cadmium, and inorganic arsenic, above the applicable safe-harbor level, and it is enforced in significant part by private parties acting in the public interest rather than only by the state. Because the safe-harbor threshold for lead is low relative to the natural background in many botanical and mineral ingredients, supplements are among the most frequently noticed product categories under Proposition 65. A supplement brand’s practical heavy-metal exposure is often a Proposition 65 question first, and a certification does not displace the warning obligation where one is triggered.
Supplements are not baby food
Dietary supplements were clarified out of the scope of California’s baby-food testing and labeling law (AB 899) in 2025, so a supplement is not subject to that statute’s monthly-testing and disclosure requirements. A supplement brand’s obligations arise under the authorities described above, not under the baby-food laws, though a product marketed for young children should be assessed carefully for where it actually falls.
What HMTc adds, and what it does not replace
The USP chapter and Proposition 65 tell a brand what bar to clear; they do not tell it how to bring a result down, how to verify a correction held, or how to turn a clean result into a claim a retailer or a consumer can check. That is the gap Heavy Metal Tested & Certified is built to close.
HMTc certifies a supplement against a published, product-specific limit on the ten-analyte panel, verified by testing rather than declared. Where a result does not meet a limit, the readiness and corrective-action pathways turn it into an investigation, a root-cause correction, and a verified retest. The result is an independently verified claim that a retailer or a buyer can check against the published register.
The boundary is firm. HMTc certification does not satisfy, replace, or discharge a brand’s obligations under Proposition 65, the FDA good-manufacturing-practice rules, or any applicable standard, and it is not a Proposition 65 safe harbor. It does not relieve a warning obligation where one is triggered. HMTc is not legal advice and does not determine a brand’s reporting, disclosure, recall, or contractual obligations. It is a way to turn testing into documented correction and a verified claim, not a substitute for compliance.
Begin by finding the standard that applies to your product. No company name is required to look one up.