Heavy Metals in Food Ingredients: A Plain-English Guide for Brand Owners and Procurement Teams in 2026

Heavy metals like lead, cadmium, arsenic, and mercury occur naturally in soil and water, so trace amounts show up in many food ingredients. For a brand, the goal is not zero, which is impossible, but knowing the sources, the rules, and the right questions to ask suppliers.

Cocoa is the clearest cautionary tale, and a useful place to learn the basics.

How Heavy Metals Get Into Food Ingredients

Regulators focus on four metals: lead, cadmium, arsenic, and mercury. All occur in the earth's crust, so plants and water pick them up to some degree. Risk depends on the amount and the total diet, not the mere presence of a trace. Common entry routes include:

• Soil uptake as crops grow, especially for cadmium and arsenic.

• Surface contamination during open-air drying, processing, or handling is a common route for lead.

• Water exposure in irrigated and paddy-grown crops, which raises arsenic levels in ingredients like rice.

Because the source varies by metal and crop, mitigation differs, too. Supplier practices matter as much as the raw material.

Why Lead and Cadmium in Cocoa Made Headlines

Cocoa shows how the same ingredient can carry two metals by two different routes. Cacao trees take up cadmium from the soil as they grow, while lead tends to settle on the beans during open-air drying, according to reporting on the research. The two metals, therefore, call for different controls.

A Consumer Reports analysis found that roughly a third of sampled chocolate products carried lead or cadmium above California's reference levels, as summarized in a US International Trade Commission briefing. Notably, some products tested low, showing that careful sourcing can reduce the levels.

Which Food Ingredients Carry the Highest Heavy Metal Risk

Cocoa gets the headlines, but several other categories deserve the same scrutiny. High-risk ingredients include:

• Spices, especially turmeric and chili powders, flagged for lead contamination from color-boosting adulteration.

• Rice and rice-based ingredients carry higher arsenic because the plant absorbs it readily from paddy water.

• Root crops and leafy greens, which pick up whatever the soil holds, making origin and soil management critical.

• Protein powders and supplements, where concentration during processing can amplify trace levels.

Procurement teams should treat any ingredient from these categories as higher-priority for testing and supplier verification.

How Brand Owners Should Manage Heavy Metals

A brand cannot remove every trace, but it can manage exposure and meet the rules. Two regulatory frameworks set the baseline:

• California Proposition 65 can require a warning label when lead or cadmium exposure passes set thresholds.

• The FDA's Closer to Zero plan, launched in 2021, aims to lower lead, cadmium, arsenic, and mercury in foods over time, with early focus on products for babies and children.

Start by asking suppliers the right questions:

• Does the supplier test for heavy metals, how often, and against which limits?

• Can the supplier provide a Certificate of Analysis (COA) showing metal results for each lot?

• What origin and processing controls are in place to keep levels low?

Pay closer attention to higher-risk ingredients such as cocoa powder, spices, and root crops.

How to Read a Heavy Metal Certificate of Analysis

A COA listing heavy metal results is only useful if a brand knows what the numbers mean. Focus on these details when reviewing a report:

• Units are typically parts per million (ppm) or parts per billion (ppb), with ppb being the finer scale.

• Metals tested should include, at a minimum, lead, cadmium, arsenic, and mercury.

• Limits compared should match the standard that applies to the product, whether a Prop 65 threshold, an FDA action level, or the brand's own internal target.

A result below the limit passes. A result near the limit warrants a conversation with the supplier about lot-to-lot trends and whether processing controls can bring it lower.

How to Build a Heavy Metal Testing Program

A one-time COA is a snapshot, not a system. A brand selling into regulated channels needs ongoing monitoring. Set frequency based on risk:

• High-risk ingredients like cocoa, spices, and rice deserve testing on every lot or at a minimum every new crop year.

• Medium-risk inputs such as root crops and leafy greens move to quarterly or seasonal testing.

• Lower-risk ingredients can rely on periodic spot checks with an annual review.

Use an accredited third-party lab, keep all results on file, and set internal action levels tighter than the regulatory floor so there is room to act before a violation.

What to Do After Finding Heavy Metals in Your Supply Chain

Identifying a problem is only the first step. What happens next determines whether it becomes a crisis or a controlled correction:

• Quarantine the affected lot and pull it from production until the scope is clear.

• Notify the supplier of the test results and request a root-cause investigation and corrective action plan.

• Assess finished product already in distribution to determine whether a recall or label update is needed.

• Evaluate alternative origins or suppliers for the ingredient if the issue is systemic rather than a one-off.

• Document everything, since regulators and retail buyers will ask for the paper trail.

Swift action protects both the consumer and the brand's credibility with retailers and regulators.

Wrap-up

Heavy metals are a normal part of the food supply, not a sign of a bad ingredient. A brand protects itself by understanding the sources, following Prop 65 and Closer to Zero, testing regularly, and acting fast when a result runs high.

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Frequently Asked Questions

What are heavy metals, and how do they end up in food ingredients?

Heavy metals such as lead, cadmium, arsenic, and mercury are naturally occurring elements in soil and water. Plants absorb some through their roots, and others settle on ingredients during drying or handling.

Why has lead in cocoa become a major news story?

Testing found that roughly a third of chocolate products carried lead or cadmium above California's reference levels. Cacao takes up cadmium from soil and picks up lead during open-air drying, making cocoa the clearest example.

What is California Prop 65, and does my brand need to comply with it?

Proposition 65 is a California law requiring a warning label when a product exposes consumers to listed substances above set thresholds. A brand selling into California should assess exposure and consult counsel, since enforcement is specific.

What basic questions should a brand owner ask suppliers about heavy metals?

Ask whether the supplier tests for lead, cadmium, arsenic, and mercury, how frequently, and against which limits. Request a COA with metal results and ask about origin and processing controls.

Is it possible to source ingredients with zero heavy metals?

No, because these metals occur naturally in soil and water, so trace levels exist in nearly all crops. The realistic goal is keeping levels as low as practical through good sourcing, processing controls, and regular testing.

How does the FDA's Closer to Zero plan affect food brands?

Closer to Zero aims to lower dietary exposure to lead, cadmium, arsenic, and mercury over time, starting with foods for babies and young children. Brands should build testing and supplier controls now to stay ahead of tightening expectations.