Custard metal content reflects its milk and egg inputs, and heating retains the metals present in those ingredients.
- Metals of concern: cadmium and lead are discussed, with chromium and nickel considered in equipment contact
- Ingredient drivers: feed and water supplying dairy cattle, the hens' feed and environment, and ingredient proportions
- Practical framing: keep prepared custard results separate from egg or milk measurements; heating does not remove metals
This page draws on evidence from UK Food Standards Agency, together with 1 peer-reviewed study. The complete citation list is at the bottom of the page.
Overview
FSA/Fera measured this ingredient or non-infant-specific food composite in Table 6 of the FS102048 survey. Exact concentration values remain in progress until Table 6 is parsed into structured ingredient rows with less-than and semi-quantitative flags preserved. Survey of metals in commercial infant foods, infant formula and non-infant specific foods
Regulatory limits that apply
Under the European Union EU Regulation 2023/915 maximum levels for contaminants in food, the maximum level for lead in liquid milk is 0.020 mg/kg (20 ppb) wet weight, one of the strictest food-category lead limits in the EU framework, reflecting the use of dairy as a major dietary staple particularly for infants and children. Custard, as a prepared dairy-based product, would fall under EU limits for processed dairy products, where the applicable lead ML depends on the product’s dairy fraction and the specific regulatory product category. For cadmium, dairy products are subject to a maximum of 0.050 mg/kg (50 ppb) under EU general food contaminant rules. Codex Alimentarius (CXS 193-1995 and revisions) sets a lead limit of 0.020 mg/kg for liquid milk. No US federal maximum level for lead or cadmium in custard or prepared dairy desserts has been finalized as of 2026.
Mitigation options
Sourcing levers
Procuring milk from dairy herds raised in regions with low soil cadmium and lead is the relevant lever, though given the low milk-to-cow transfer factors for these metals, even moderate contamination of dairy cow feed is unlikely to materially elevate custard metal content under normal commercial conditions. Egg sourcing from commercial laying flocks on formulated low-metal feed reduces any egg-origin metal contribution.
Agronomic levers
No custard-specific agronomic lever applies. For dairy-origin cadmium, see Butter and ghee and ingredients/milk when those pages are created; for egg-origin metals, see Eggs.
Processing levers
No processing-level intervention is specifically applicable for reducing heavy metals in custard beyond selecting clean-sourced inputs. Standard food safety cleaning of equipment between production runs is not a metal-control issue for this product category.
Formulation levers
No quantified data on formulation substitution effects on custard metal content is in the current corpus; section will be expanded when relevant evidence is ingested.
Testing and QC levers
Given that custard is a low-risk matrix under normal production conditions, heavy metal testing of finished custard products is lower priority than testing of higher-risk ingredient categories. Periodic cadmium and lead testing of the milk and egg inputs that feed into custard production is the most efficient testing leverage point.
Packaging and storage levers
No quantified data on packaging or storage effects on heavy metal content in custard is in the current corpus; section will be expanded when relevant evidence is ingested.
Why this commodity accumulates heavy metals
Custard is a dairy-based preparation made primarily from milk or cream, egg yolks, and sugar, cooked until thickened by egg protein coagulation. Its heavy metal risk profile is low for most analytes, reflecting the generally clean metal status of both dairy and eggs under normal commercial production conditions. Milk carries metals primarily as a function of the dairy cow’s feed and water supply: cadmium and lead are poorly transferred from feed into milk, with transfer factors typically below 0.01 (less than 1% of dietary metal appears in milk on a comparable weight basis), which is why dairy products appear at the low end of dietary metal exposure estimates. Egg yolk contributes trace metals at concentrations reflecting the hen’s feed and environment, but under commercial laying hen conditions where feed is formulated from low-metal ingredients, egg metal content is low.
The FSA/Fera FS102048 survey measured custard or equivalent dairy composite as part of its non-infant food survey Table 6, providing the primary sourcing anchor for this page Survey of metals in commercial infant foods, infant formula and non-infant specific foods. Exact values from that table await structured parsing. Custard’s composite nature (milk plus egg plus sugar plus starch) means that even if any single component carries trace metals, the dilution effect of mixing multiple low-risk ingredients reduces the per-gram metal burden in the finished product further.
Heavy metal contamination profile
This table summarizes the available occurrence evidence for each metal. A data gap means the literature was reviewed for this commodity and metal but no usable occurrence data was found. Key sources link to contributing studies.
| Analyte | Coverage | Typical (ppb) | Confidence | Key sources |
|---|---|---|---|---|
| lead (Pb) | n=1 | 0–14.8 | low | — |
| cadmium (Cd) | n=1 | 0–4.3 | low | — |
| inorganic arsenic (iAs) | n=1 | 0–11.2 | low | — |
| total arsenic (tAs) | data gap | — | — | — |
| total mercury (tHg) | n=1 | 0–1 | low | — |
| nickel (Ni) | data gap | — | — | — |
| aluminum (Al) | n=1 | 0–1734 | low | — |
| chromium (Cr) | data gap | — | — | — |
| tin (Sn) | n=1 | 0–200.6 | low | — |
| uranium (U) | data gap | — | — | — |
Routing
This ingredient is listed in the ingredient index.
Contamination Profile State
Per-analyte state — populated, in progress, or declared data gap — is carried authoritatively in the machine-readable contamination_profile frontmatter and the contamination-profile table above. Ingredient-level values belong here; finished-product values belong on the relevant product-category page.
Ranges by source, region, and variety
The only structured source for custard heavy metal levels currently integrated into this corpus is the FSA/Fera FS102048 survey, which measured metal concentrations in custard as part of a broader UK survey of non-infant foods Survey of metals in commercial infant foods, infant formula and non-infant specific foods. Exact values remain in progress pending structured table parsing. No peer-reviewed multi-region survey specifically characterizing heavy metal concentrations in custard products is in the current corpus.
Regional variation in custard metal content would be expected to follow the variation in its primary inputs: milk from dairy cattle in regions with elevated soil cadmium or lead, or where cattle consume contaminated forage, could contribute higher metals to custard than milk from low-contamination regions. Similarly, eggs from hens with unusual environmental metal exposures (for example, near mining areas, as documented in Thailand by Heavy metal contamination in eggs on poultry farms and ecological risk assessment around a gold mine area in northern Thailand for eggs generally) could contribute more metal to custard than eggs from standard commercial production systems.
Processing effects
Custard preparation involves heating the milk-egg mixture to coagulate proteins and thicken the product, then cooling. This thermal processing does not reduce heavy metal concentrations; metals in the dairy and egg inputs are retained in the set custard matrix. Sugar and starch thickeners, if used, add negligible metals.
Commercial custard production uses stainless steel equipment, which contributes negligible chromium or nickel to a neutral-pH dairy product under normal processing temperatures, unlike acidic or high-temperature industrial processes where equipment leaching is more relevant.
Ingredient-derivative risk
Custard is a finished product rather than an industrial ingredient in most contexts. In confectionery and bakery applications, custard powder or custard filling may be used as a component of pastries, trifles, or confections. Custard powder (typically starch, colouring, and flavouring with no dairy) is a different product category from dairy custard. In all cases, the metal contribution from a custard component to a composite product will be proportional to its weight fraction and the low metal concentrations of the dairy and egg inputs.
References
Works cited in this page’s text, in first-appearance order. See Sources for this page’s source inventory. Each title links to a source record with bibliographic details, reported findings, and document provenance.
- Survey of metals in commercial infant foods, infant formula and non-infant specific foodsGovernment
- Heavy metal contamination in eggs on poultry farms and ecological risk assessment around a gold mine area in northern ThailandPeer-reviewed
Sources
Update history
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