Prop 65
California's chemical-warning law, with heavy-metal limits far stricter than federal standards.
California Proposition 65 requires warnings for products that expose consumers to listed chemicals above "safe harbor" levels. For supplements, its heavy-metal thresholds (especially for lead, at 0.5 mcg/day) are far stricter than USP <2232>.
If your product can be shipped to California - which, on Amazon, means essentially every product - Prop 65 applies. The plaintiff's bar actively buys products, tests them, and sends 60-day notices. Set your heavy metals specs to Prop 65 limits, not just USP.
Related terms
Guides that cover Prop 65
Heavy Metal Testing for Supplements: Methods, Costs, and What You're Actually Testing For
ManufacturingContract Manufacturer Testing: Why 'They Handle It' Is the Most Dangerous Phrase in Supplements
Getting StartedHow to Read a Certificate of Analysis: What the Numbers Actually Mean
SpecializedCBD Testing: Potency, THC Limits, and the Tests That Keep Your Product Legal
ComplianceProp 65 Supplement Testing: Don't Wait for the Lawsuit Letter
ManufacturingHow to Source Ingredients That Actually Pass Prop 65 Testing
ComplianceCalifornia vs. Federal Supplement Testing: Why FDA Compliance Isn't Enough
SpecializedMushroom Supplement Testing: Is It Actually Mushrooms or Just Grain Powder?
Getting StartedHow to Test Your Supplement Before Selling (First Batch Checklist)
FDA & GMPSupplement Finished Product Testing: The GMP Release Checklist
Free ResourcesFree Supplement Specification & COA Templates
Ingredient TestingAshwagandha Testing: Withanolides, Root Auth, Heavy Metals
Test MethodsGlyphosate Testing Supplements: LC-MS/MS Residue Detection, Claims
SpecializedGreens Powder Testing — Heavy Metals, Pesticides, Nutritional Panel
Test MethodsICP-MS vs AAS for Supplement Heavy Metal Testing — Which Method?
Ingredient TestingIron Supplement Testing: ICP-MS Potency, Form Verification, Disint
Getting StartedISO 17025 for Supplement Testing, Explained
SpecializedOmega-3 & Fish Oil Supplement Testing — EPA, DHA, TOTOX
Test MethodsPesticide Testing for Supplements — Multi-Residue Screen Guide
Ingredient TestingPrenatal Vitamin Testing: Folate Form, Heavy Metal Safety, Potency
Ingredient TestingProtein Powder Testing: Heavy Metals, Amino Spiking, and Real Protein Content
Ingredient TestingSea Moss Testing: Iodine Content, Heavy Metals, Species Auth
Ingredient TestingSpirulina Chlorella Testing: Microcystin, Heavy Metals, Micro
Getting StartedThird-Party Supplement Testing: Why It's Non-Negotiable
Test MethodsUSP 2232 Heavy Metals Testing Explained
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