The lead, cadmium and PFAS in your chocolate, and the industry's fix: grow it in a lab

Dark chocolate has a heavy metal problem, chocolate wrappers have a "forever chemical" problem, and the industry's biggest response to both isn't a cleanup — it's a bioreactor. Mondelez, the company behind Cadbury and Oreo, is now growing cocoa butter from plant cells instead of cocoa beans. Here is what the actual lab results say, what happened to the lawsuits, and why "lab-grown" cocoa butter wouldn't even fix the problem it's being pitched against.

The Consumer Reports numbers

In December 2022, Consumer Reports tested 28 dark chocolate bars for lead and cadmium. Every single one contained both metals. Twenty-three of the 28 exceeded California's Maximum Allowable Dose Level (MADL) — the "safe harbor" threshold under the state's Prop 65 law — for at least one of the two metals, and five exceeded it for both.

Lindt's Excellence line was named specifically:

Other brands that ran high in the same test included Theo, Trader Joe's Dark Chocolate Lover's, and Green & Black's. Brands that tested lowest included Mast and Taza.

The lawsuit that didn't survive

Those numbers did produce a class action: Harkavy v. Lindt & Sprüngli (North America) Inc., filed January 10, 2023 in the U.S. District Court for the Northern District of California (Case No. 3:23-cv-00121). The plaintiff voluntarily dismissed it without prejudice on February 27, 2023 — meaning it could technically be refiled, but nothing has replaced it as of this writing. A dismissed lawsuit doesn't erase a lab result; it just means no court ever ruled on whether Lindt owed anyone anything for it.

A wider, newer study says it's actually improving

A separate peer-reviewed analysis in Frontiers in Nutrition looked at 72 cocoa products tested across four collection years — 2014, 2016, 2019, and 2022. Across the full set: 43% of products exceeded the Prop 65 lead limit and 35% exceeded the cadmium limit, while arsenic was essentially a non-issue at 0% over its limit. The trend line matters here — later years showed measurably lower lead and arsenic levels than the 2014 baseline, a statistically significant improvement. The study's most counterintuitive finding: products labeled "organic" tested significantly higher for both cadmium and lead than non-organic ones, the opposite of what the label implies.

Why dark chocolate specifically? Cadmium gets pulled up from soil by the cacao plant itself, and lead settles onto beans during drying and processing. Both concentrate almost entirely in the nonfat cocoa solids — the "chocolate liquor" — not in the cocoa butter. That distinction matters further down.

Hershey's separate problem: the wrapper, not the bar

Hershey is fighting a different fight. On October 29, 2024, Jonathan Parish filed a proposed class action in the U.S. District Court for the Middle District of Pennsylvania (Case No. 1:24-cv-01868), alleging independent lab testing found organic fluorine — the standard marker for PFAS, "forever chemicals" — in the wrappers of eight products: Hershey's Milk Chocolate bars, Hershey's Cookies 'n' Creme bars, Hershey's Kisses, Reese's Peanut Butter Cups, Reese's Pieces, Almond Joy, Mounds, and Kit Kat. A second, related case, Beekman v. The Hershey Company, was filed December 24, 2024 in New York under that state's consumer protection statutes.

Hershey moved to dismiss both on June 27, 2025, arguing the claims were "a house of cards" and that it had banned PFAS from its packaging "for well over a decade." Both cases remain pending — no ruling, no settlement, as of this writing. PFAS in food packaging is also now under direct FDA pressure: July 1, 2025 was the cutoff date after which manufacturers could no longer use up existing stockpiles of PFAS-based grease-proofing agents in new packaging.

The industry's answer: skip the bean

While that plays out in court, Mondelez has been quietly funding a way around the cocoa supply chain altogether. Celleste Bio, an Israeli biotech startup, grows cocoa butter from cultured plant cells in bioreactors rather than pressing it from beans. Mondelez first invested in the company in 2022, then joined a $4.5 million seed round led by Supply Change Capital to scale the process. In October 2025, the two announced a breakthrough: Celleste Bio's cell-cultured cocoa butter is now "bio-identical" to bean-derived cocoa butter at chocolate-manufacturing grade, with Mondelez putting in $15 million and acting as a design and strategy partner rather than just an investor.

The scale-up plan is specific: Celleste says it's moving from roughly 10 liters of output in the lab to 1,000 liters within a year, and past 10,000 liters at commercial scale by 2027 — the same year the company is targeting for lab-grown chocolate to reach store shelves in real volume. Longer-term, Celleste has stated a goal of 50,000 tons a year by 2035, which it frames as roughly 5% of the 2 million tons of cocoa butter the global chocolate industry uses annually. The timing lines up with cocoa itself: futures spiked past $12,000 a ton in December 2024 amid West African crop shortfalls — the actual business problem Mondelez is hedging against, not the lead and cadmium headlines.

Why lab-grown cocoa butter wouldn't fix the metals problem anyway

This is the part that doesn't show up in the press releases: heavy metals in chocolate concentrate in the nonfat cocoa solids, not the cocoa butter, because cadmium and lead aren't fat-soluble contaminants — they stay with the solids the fat is pressed away from. So even if Celleste Bio's cell-cultured cocoa butter fully replaces bean-derived cocoa butter at commercial scale, a chocolate bar still needs actual cocoa solids (or chocolate liquor) to taste like chocolate and carry its flavanols — and that's exactly where the Consumer Reports numbers and the Prop 65 exceedances live. Lab-grown cocoa butter is a hedge against a volatile, climate-squeezed cocoa supply chain. It is not, on the facts here, a fix for what the lawsuits and lab tests are actually about.

None of this — the metal levels, the wrapper testing, or which cocoa butter went into a given bar — is printed anywhere on the wrapper. Scan a chocolate bar in the Tallow app before you buy it and it flags known heavy-metal, PFAS, and additive risk behind the ingredient list, with a plain 0–100 score based on your own standards.

Maddox Schmidlkofer is the founder of Tallow.