Why is nickel limited in food? The certification rationale

In brief

Nickel is limited in food because exposure has already overtaken the guidance value. When EFSA reassessed nickel in 2020 it set a chronic tolerable daily intake of 13 µg/kg body weight per day, and found that average European dietary intake already exceeds it, with the most-exposed young children exceeding it by more. A separate acute concern applies to the substantial fraction of people who are nickel-sensitized, who can react to oral doses far below the chronic value. Because nickel enters food mainly through plant uptake and is controllable through sourcing and process control, a certification limit that adopts the strictest government ceiling and holds the cleaner part of the market to it is a workable lever.

The health basis for limiting nickel

Nickel’s dietary regulation rests on two distinct endpoints. For chronic exposure, EFSA’s 2020 CONTAM opinion established a tolerable daily intake of 13 µg nickel/kg body weight per day, anchored on a BMDL10 of 1.3 mg/kg body weight per day for increased post-implantation loss in animal studies — a reproductive and developmental endpoint. The finding that made this a live regulatory concern is the exposure comparison: mean dietary intake in Europe already exceeds the tolerable intake, and the most-exposed young children exceed it further. For acute exposure, EFSA identified eczematous flare-up reactions in nickel-sensitized people — systemic contact dermatitis — as the critical effect, with a reference point (a LOAEL of 4.3 µg/kg body weight) far below the chronic value, which matters because nickel sensitization is common.

Nickel compounds are also classified by IARC as Group 1 and by the US National Toxicology Program as known human carcinogens, on inhalation evidence for lung and nasal cancer — a route distinct from the dietary endpoints. The full agency record is on the nickel analyte reference.

Who the exposure reaches

Two populations are most affected. The first is young children, whose intake per unit of body weight is highest and who therefore sit furthest above the tolerable intake on the chronic endpoint. The second is the large group of nickel-sensitized individuals, for whom an oral dose well under the chronic guidance value can trigger a systemic dermatitis flare. Because a program certifying infant and child foods is aimed squarely at the first group, and because the plant staples that carry nickel recur through a child’s diet, keeping the number down is a direct benefit to the eaters the standard is written for.

Where nickel shows up in food

Nickel enters food chiefly through plant uptake, so it concentrates in plant staples: legumes and pulses, whole grains and oats, nuts, soy, and cocoa and chocolate. These are exactly the ingredients that anchor many infant and child foods and plant-forward diets, which is why nickel exposure tracks the diet’s reliance on them. A secondary route is leaching from nickel-bearing stainless steel during cooking and processing, which can add to the food’s own load.

The per-category occurrence figures and the derivation behind each limit are on the standards register; the complete occurrence corpus is on the Heavy Metal Index.

Why a certification limit is warranted

When mean intake already exceeds the tolerable value, the useful response is not another safe-dose claim but a push on the controllable sources — and nickel is largely controllable through sourcing and process control. The EU set its first binding nickel maximum levels in food in 2024, a risk-management response to the EFSA exceedance finding, with category limits ranging from 0.10 mg/kg for liquid infant formula to higher values for cereals and seaweed.

HMTc treats nickel as a Tier-2 metal: it adopts the strictest existing government maximum level directly, computing an occurrence value only where no government sets one, and applies the program’s 150% transitional allowance so a category can move onto the standard on a defined path to the firm limit. A regulatory hard-stop blocks certification of any product over an applicable legal limit. How the limit is derived is set out under how limits are derived.

Findings that bear on Nickel

Program analyses that trace how nickel enters specific foods. Each covers a finding from the independent Heavy Metal Index and applies it to the certification question; the underlying occurrence record is on the Index.

Frequently asked questions

Evidence and sources

This page synthesises three surfaces that carry the underlying evidence, and links to them rather than re-hosting them:

The Heavy Metal Index is an independent literature reference; this certification site cites it one way and applies its evidence to the certification question. The Index never cites back — that is what keeps it a disinterested source.

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