Nickel

Nickel is limited because EFSA's 2020 reassessment set a chronic tolerable daily intake of 13 µg Ni/kg body weight/day on a reproductive-developmental endpoint that mean European dietary intake already exceeds, and because sensitized individuals react to oral doses far below that; contamination is largely controllable through sourcing and process control.

Why it is limited

The government and expert-body assessments that underpin limiting nickel in food, and what each concluded. The maximum levels in force apply these findings; this page is the rationale, not the certification threshold.

Toxicological basis

What the assessment bodies found when they examined nickel, and why it warrants a limit: the dietary endpoint that anchors regulation, the sensitized population it reaches at far lower doses, and the carcinogenicity that does — and does not — apply to food.

The hazard that anchors dietary regulation is reproductive and developmental. Across multi-generation rat studies the most sensitive and consistently reproduced effect of oral nickel is increased post-implantation loss, accompanied by reduced fetal weight and reduced offspring viability. EFSA's 2020 reassessment set the chronic tolerable daily intake at 13 µg Ni/kg body weight per day from a BMDL10 of 1.3 mg/kg, a value it lowered substantially from its earlier reference under revised benchmark-dose methodology. This is the endpoint governments regulate against, and it is not academic: EFSA found that mean dietary nickel exposure across European member states already exceeds the tolerable intake, with toddlers and young children the most exposed on a body-weight basis.

A second, lower-dose endpoint reaches a far larger population. Nickel is among the most common contact allergens, sensitizing an estimated 8 to 19 percent of adults and 13 to 18 percent of women, and once a person is sensitized, oral doses well below the chronic tolerable intake can provoke systemic contact dermatitis; EFSA set the acute reference at a LOAEL of 4.3 µg Ni/kg body weight for eczematous flare-ups in sensitized volunteers. Systemic Nickel Allergy Syndrome, which affects roughly one in five nickel-allergic patients, extends the picture beyond the skin: controlled and open-label low-nickel-diet trials report symptom improvement in nickel-sensitized patients with chronic dermatitis, irritable bowel syndrome, refractory reflux, recurrent aphthous stomatitis, and endometriosis-associated gastrointestinal symptoms, and a nickel-free diet has been shown to nearly double Helicobacter pylori eradication when added to standard therapy. The evidence ranges from double-blind oral-challenge studies to small pilots; its breadth is the point, because it means dietary nickel is a clinically active exposure for a population much wider than the reproductive endpoint alone describes.

Nickel is also a carcinogen, and being precise about how is a matter of credibility. The US National Toxicology Program lists nickel compounds as known human carcinogens and metallic nickel as reasonably anticipated to be one, and IARC classifies nickel compounds in Group 1. The tumour sites — lung and nasal-sinus — were established in occupational cohorts inhaling nickel dust and fume, not in people eating nickel; typical dietary nickel intake has not been associated with cancer. The program states that plainly rather than blur an inhalation hazard into a food-safety claim the record does not support.

These are not the finding of a single body. EFSA, the US Agency for Toxic Substances and Disease Registry (which derives route- and duration-specific minimal risk levels), the National Toxicology Program, and IARC independently characterise nickel's reproductive, sensitization, and carcinogenic hazards, and they converge. California adds a further mark of concern: its Proposition 65 programme lists soluble nickel compounds as reproductive and developmental toxicants and nickel compounds as carcinogens, yet — as a right-to-know statute that sets no food standard — it adopts no oral safe-harbour and no dietary limit, so the operative dietary reference defaults to EFSA's tolerable intake while the United States sets no maximum level in food at all. That convergence of hazard findings, together with EFSA's exposure exceedance, is what moved the European Union to adopt its first binding nickel maximum levels in food in 2024. The science came first; the limits followed, and where they have not yet followed, the gap is visible.

Occurrence & exposure

How much nickel food actually carries, and how close everyday dietary exposure runs to the health-based guidance value. This is the empirical basis for carrying nickel in the panel, drawn from a national total diet study; the complete occurrence corpus is on the Heavy Metal Index.

Nickel by food group — BfR MEAL Study (Germany, 2022), 840 food pools. Values are µg/kg (ppb), upper-bound, ready-to-eat basis: the group mean and the single highest item measured. These are population occurrence values, not safety thresholds.

Dietary nickel intake against the EFSA tolerable daily intake of 13 µg/kg body weight per day. BfR MEAL Study, upper-bound; the share of the tolerable intake reached by the median (P50) and high (P95) consumer.

Grains and grain products are the single largest contributor to children's nickel intake, followed by sugar and confectionery, dairy, and dedicated infant and toddler foods — every one a category the program certifies. Cocoa, nuts, seeds and soy carry the highest concentrations per kilogram, so a product built on those ingredients inherits nickel as a leading concern.

The exposure sits exactly where the program works. Child dietary nickel already reaches the majority of the tolerable intake, a measurable fraction of young children exceed it, and the foods driving that intake are child-food staples rather than exotic exposures. That is the empirical case for quantifying nickel in every certified lot rather than treating it as a trace afterthought.

German Federal Institute for Risk Assessment (BfR), Communication 033/2022 — a government total diet study of 840 nationwide food pools (evidence tier A). EFSA's 2020 pan-European reassessment reaches the same conclusion: mean dietary nickel exposure across Member States exceeds the tolerable intake, children most of all. The full occurrence corpus is on the Heavy Metal Index.

How it is regulated

The binding maximum level in force for infant and child foods is the EU's, adopted under Method v2.0 (government-limit default) as the strictest sovereign limit by lookup. The EU is effectively the only jurisdiction that regulates nickel in food (limits introduced by Reg (EU) 2024/1987 amending 2023/915, Annex 3.6): liquid infant formula 100, non-soy formula powder 250, soy-isolate formula powder 400, baby food except juices 500, cereals 800, and processed cereal-based baby food / pseudocereals and millet 3000 µg/kg (see cert /regulations/eu-2023-915). No US/FDA, Codex, UK, Canada, China, India, Brazil or AU/NZ nickel food ML exists, so the EU value governs across the program and, where no government regulates the exact product, a disclosed read-across from the nearest EU value is applied rather than an invented number. For teething and finger snacks the EU processed-cereal-based value (3000 µg/kg) binds; the law's own formulation split (250 cow-milk vs 400 soy powder) is adopted verbatim per Method v2.0 rather than derived. Do not restate the full derivation table — see the cert standards pages and /regulations/ for the side-by-side.

How the HMTc program treats it

Nickel is a Tier 2 analyte in the HMTc program (with Al, Sn, Cr), not a Tier 1 zero-tolerance toxic. Under Method v2.0 the government limit is adopted directly for Tier 2 metals (occurrence pooling is reserved for Tier 1 toxics and no-ML cells), and Tier 2 analytes carry the program's 150% transitional allowance under the Status A–E framework (Status B = public transitional certification), giving brands a defined runway to reach the government floor. The certification species is Total elemental nickel; nickel carries NO speciation trigger — unlike arsenic (iAs), mercury (MeHg/tHg) and chromium (reflex Cr-VI speciation above 100 ppb). The regulatory hard-stop still applies: any actual legal-limit violation blocks certification regardless of HMTc status. The program frames nickel as largely controllable through ingredient sourcing and process control.

Literature baseline

The complete peer-reviewed and regulatory literature for nickel is maintained independently at the Heavy Metal Index. That reference reports what the literature says; this certification site applies it. The two are kept editorially separate by design.