Which Certifications Test for Lead? Limits Compared
Third-party certifications test for lead, but their limits vary dramatically. NSF allows 20x more lead than California Prop 65. See where tested products fall relative to each certification's lead limits.
Certification Lead Limits
| Certification | Lead Limit | vs Prop 65 | Products Passing |
|---|---|---|---|
| California Prop 65 | 0.5 µg/day | 1x (benchmark) | 9/15 tested |
| NSF Certified for Sport | ≤10 µg/day | 20x higher | 15/15 tested |
| Informed Sport/Choice | Not specified | Unknown | — |
🇺🇸 United States • 23 Products (incl. NSF-only)
Lead content per serving. Lower = safer
SupplementMath.com
Lower values = safer. Bars are color-coded by concern level.
Where Products Fall by Standard
California Prop 65 (0.5 µg/day limit)
9
Would Pass
6
Would Fail
120
Not Tested
Products above this limit would require warning labels in California.
NSF Certified for Sport (10 µg/day limit)
15
Would Pass
0
Would Fail
120
Not Tested
NSF allows 20x more lead than Prop 65 — "passing" products may still contain significant lead.
Key Takeaways
Certification ≠ Low Lead
NSF certification does not guarantee low lead. NSF allows 20x more lead than Prop 65. Many certified products would require warning labels in California.
Prop 65 is the Strictest Standard
California's Proposition 65 sets 0.5 µg/day for lead — the strictest limit in the United States and our benchmark for "low concern" products.
Most Products Are Untested
120 of 135 products in our database have no independent lead testing data.
Recommendation
If lead is your primary concern: Look for products below 0.5 µg/serving. Don't assume certification means low lead — check the actual test data.
If athlete certification is your priority: NSF or Informed Sport is valuable for banned substance testing, but be aware their lead limits are higher than Prop 65.
Data Sources: Consumer Reports 2025, Labdoor, Clean Label Project. Certification lead limits are obtained from publicly available standards and organization documentation.