The Science Behind the Lawsuit
Peer-reviewed studies from UC Berkeley and Columbia University detected heavy metals in all 30 tampon samples tested — including Tampax products. Here is what the research actually found.
Toxicological Risk: Why Lead in Tampons Is Different
Route of exposure matters. When lead is ingested through food or water, it passes through the gastrointestinal tract where absorption is limited — typically 10–15% in adults. The liver then filters additional circulating lead. By contrast, transmucosal absorption (through mucous membranes like vaginal tissue) can bypass hepatic first-pass metabolism entirely.
Vaginal permeability. The vaginal epithelium is significantly more permeable than keratinized skin. Studies on vaginal drug delivery (used medically for hormone therapies and antifungals) demonstrate rapid absorption into systemic circulation — the same pathway that makes tampons a concern for metal transfer.
Lead's neurotoxicity. The CDC and WHO recognize that there is no safe level of lead exposure. Lead disrupts heme synthesis, crosses the blood-brain barrier, and causes irreversible neurological damage. In adults, chronic low-level exposure is associated with hypertension, cognitive decline, and reproductive harm. In the context of menstruation — a monthly, repeated exposure over decades — cumulative risk is the central argument in all active lawsuits.
Cadmium and arsenic co-exposure. The 2024 study found cadmium (a known human carcinogen classified Group 1 by IARC) and arsenic simultaneously with lead. Cadmium accumulates in the kidneys with a biological half-life of 10–30 years. Combined heavy metal exposure may produce additive or synergistic toxicity beyond any single metal.
FDA's Leaching Study: What It Means for the Cases
The FDA launched a formal investigation in October 2024 and is currently conducting in vitro leaching experiments — simulating the conditions of tampon use to measure whether metals actually migrate from the tampon matrix into simulated vaginal fluid at physiologically relevant concentrations.
This distinction is legally critical: the plaintiffs argue that presence of metals constitutes a defect and a failure to warn. P&G argues that presence does not equal transfer. The FDA's leaching data — expected in 2026 — is likely to be decisive in class certification hearings for both Otkina and Sanchez.
If the FDA confirms meaningful leaching, it would constitute strong independent corroboration of plaintiffs' core claim and significantly increase settlement pressure on P&G.
The 2024 Study — Environment International
Published August 2024 | Researchers from UC Berkeley & Columbia University Mailman School of Public Health
Researchers tested 30 tampons from 14 different brands, including Tampax. They analyzed concentrations of 16 metals and metalloids.
Key finding: 100% of samples contained measurable concentrations of at least 12 toxic metals, including lead, arsenic, cadmium, and chromium.
Notable paradox: Non-organic tampons had higher lead concentrations, while organic tampons tested higher for arsenic — meaning "organic" labeling does not guarantee safety from all heavy metals.
The Vaginal Permeability Problem
The central scientific argument in all active lawsuits rests on a critical biological fact: vaginal tissue is significantly more permeable than regular skin.
This means toxic metals like lead and cadmium may bypass the liver's normal filtration process and enter the bloodstream directly — unlike metals ingested through food or water. This is why researchers and plaintiff attorneys argue that even trace levels in tampons are more dangerous than similar levels in, say, tap water.
P&G's Defense Position
OEKO-TEX Certification: P&G states that Tampax tampons hold OEKO-TEX Standard 100 certification, which tests for over 1,000 harmful substances.
"Naturally Occurring" Argument: P&G argues that trace metal levels found are comparable to what naturally occurs in soil, food, and drinking water.
Court Challenge: In the PFAS case (dismissed July 2025), a California judge ruled plaintiffs' testing methodology was flawed — though this does not affect the newer lead contamination cases.
FDA Investigation Status (2026)
The FDA launched a formal investigation in October 2024 following the initial study. As of May 2026, the agency is conducting "leaching" experiments to determine whether metals actually transfer from tampons into the bloodstream during use. Results are expected to be a major factor in the litigation.
Primary Sources & Citations
- [1]Ragusa A. et al. (2024). Metals in tampons: an exploratory study. Environment International, 190. DOI: 10.1016/j.envint.2024.108890
- [2]UC Berkeley School of Public Health — Tampon Study Press Release (Aug 2024)
- [3]Columbia University Mailman School of Public Health — Research Summary
- [4]FDA — Tampon Safety & Consumer Information (Updated 2024)
- [5]EPA Drinking Water Lead Action Level — 15 ppb (40 CFR Part 141)
- [6]OEKO-TEX Standard 100 Certification — P&G Tampax listing