One retail unit of a 40% zinc oxide maximum-strength diaper rash paste contained 4657.1 ppb lead and 473.1 ppb cadmium as received, by ICP-MS at an independent laboratory. Arsenic and mercury were below the reporting values. This is the highest lead result among the four single-product laboratory reports in this collection.
Key numbers
Laboratory report: Purity Laboratories, Inc.; case 2508207; received 08/14/2025, tested and completed 08/20/2025. The sample was described to the laboratory as “Max Strength Diaper Rash Paste Lot# 2025-182”. The advocate’s annotation identifies a 40% zinc oxide skin protectant marketed for moderate to serious diaper rash.
| Analyte | Result (ppb, as received) | Note |
|---|---|---|
| Arsenic | < 10.00 | below reporting value; not speciated |
| Cadmium | 473.1 | detected |
| Lead | 4657.1 | detected |
| Mercury | < 5.00 | below reporting value; not speciated |
The article describes the result as “over 4,000 ppb Lead”, which matches the report. It compares the result with the Washington State Toxic-Free Cosmetics Act figure of one part per million (1,000 ppb) and says the state agency may decline to act because the product is sold with medical properties.
Methods (brief)
ICP-MS. No sample mass, digestion, calibration, recovery, detection limit or accreditation is printed. Results apply to the sample as received. Arsenic and mercury are totals.
Evidence fitness
The report supports one as-received result for this unit. It does not support statements about other lots, the brand, the category, absorbed dose, or legality.
Limitations
This is a single advocate-selected sample with no quality-control data. The ’<’ entries are reporting values. The article’s regulatory comparison is the author’s and draws on an instrument that is not in this collection.
Related evidence
- Diaper Cream, ZnO-Based
- Consumer-advocacy comparison chart of lead, cadmium, mercury and arsenic in eleven diaper creams (updated January 2026)
- Lead
- Cadmium
Update history
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