Clinical Pharmacist and Master’s student in Clinical Pharmacy with research interests in pharmacovigilance, behavioral interventions in mental health, and AI applications in clinical decision support. Experience includes digital health research with Bloomsbury Health (London) and pharmacovigilance practice in patient support programs. Published work covers drug awareness among healthcare providers, postpartum depression management, and patient safety reporting. 
Clinical Pharmacist and Master’s student in Clinical Pharmacy with research interests in pharmacovigilance, behavioral interventions in mental health, and AI applications in clinical decision support. Experience includes digital health research with Bloomsbury Health (London) and pharmacovigilance practice in patient support programs. Published work covers drug awareness among healthcare providers, postpartum depression management, and patient safety reporting. What was studied?
This original research study quantified lead-migration-from-cans and other metal transfers from lacquered tinplate packaging into canned chickpeas under realistic storage conditions relevant to a heavy metal certification program. The authors measured iron (Fe), lead (Pb), cadmium (Cd), and tin (Sn) in chickpea contents over 3 months while varying storage temperature (5°C, room temperature, and 40°C), then extended the work with brand-to-brand comparisons and an evaluation of dented versus intact cans to isolate container-related drivers of metal release. Metals were determined by atomic absorption spectrometry after microwave digestion, using FAAS for Fe and Sn and GFAAS for Pb and Cd, with method performance supported by calibration strength, low quantification limits relative to common guideline limits, and spike recoveries consistent with suitability for food matrices.
Who was studied?
No human participants were studied; the “subjects” were commercially produced canned chickpeas and their packaging systems. The primary monitoring experiment used cans from a single Lebanese producer (brand A) obtained directly after sterilization (t = 0) to reduce variability from prior storage and distribution, then stored under controlled temperatures and sampled at scheduled intervals. Additional comparisons evaluated other market-available chickpea brands (a second Lebanese brand and a foreign brand) and contrasted cans with a one-year difference in production date to assess how container characteristics, headspace, and brine formulation correspond with differences in iron and lead behavior. Finally, dented cans from the same production date were compared with undamaged cans to estimate the effect of physical damage on protective coatings and corrosion-driven migration.
Most important findings
Across storage conditions, Fe and Pb were the metals of practical concern for certification screening, while Cd and Sn showed minimal change over the 3-month window; critically, lead-migration-from-cans accelerated after ~50 days, implying that short-term stability checks can miss later-stage increases.
| Critical point | Details |
|---|---|
| Iron increased rapidly then plateaued | Fe rose from ~5.5 µg/g at t=0 to a plateau near ~27 µg/g (~27 mg/kg) after ~50 days, with little temperature effect, consistent with corrosion promoted by chickpea acidity (reported pH ~5.08). |
| Lead showed delayed acceleration and temperature sensitivity | Pb migration was slow until ~50 days, then increased rapidly at ~22°C and 40°C; 5°C slowed migration. Equilibrium was not reached by 90 days, indicating potential for continued increase toward end-of-shelf-life. |
| Cadmium remained stable within observed period | Cd concentrations did not meaningfully change over 3 months (reported range roughly 0.0146–0.0252 µg/g), staying below commonly cited maximum levels for canned vegetables; however, the authors cautioned that slow migration could occur over longer storage. |
| Tin was largely undetectable short-term but present long-term | Sn stayed below detection during 3 months; a separate 18-month can showed measurable Sn (~17.8 µg/g), still far below widely used acceptability limits, supporting long-horizon verification when tinplate is used. |
| Packaging and formulation differences mattered across brands | Over a one-year production-date difference, Fe increased in Lebanese brands A and B but not meaningfully in foreign brand C; observed differences were attributed to coating quality/thickness, free internal volume (headspace), and brine composition, including citric acid presence as a corrosion enhancer. |
| Physical damage increased migration risk | Dented cans showed higher Fe (+18%) and Pb (+38%) than undamaged cans from the same production date and storage conditions, consistent with coating disruption increasing corrosion pathways. |
Key implications
For HMTC-aligned oversight, the study indicates that lead-migration-from-cans is time-dependent with a late acceleration phase, so regulatory impacts include shifting from single-point testing to storage-time profiling for tinplate foods. Certification requirements should include: defined aging intervals beyond 50 days, temperature-conditioned testing, and acceptance criteria that consider end-of-shelf-life risk rather than early-life compliance. Industry applications include improving coating continuity, minimizing headspace, and reviewing brine acidulants (e.g., citric acid) that may increase corrosion. Research gaps include longer follow-up to expiry and broader denting/handling datasets; practical recommendations are to add dent-damage screening and to pair product testing with container audits (coating specs and defect rates).
Citation
Kassouf A, Chebib H, Lebbos N, Ouaini R. Migration of iron, lead, cadmium and tin from tinplate-coated cans into chickpeas. Food Additives & Contaminants: Part A. 2013;30(11):1987-1992. doi:10.1080/19440049.2013.832399
Lead is a neurotoxic heavy metal with no safe exposure level. It contaminates food, consumer goods and drinking water, causing cognitive deficits, birth defects and cardiovascular disease. HMTC’s rigorous lead testing applies ALARA principles to protect infants and consumers and to prepare brands for tightening regulations.
Cadmium is a persistent heavy metal that accumulates in kidneys and bones. Dietary sources include cereals, cocoa, shellfish and vegetables, while smokers and industrial workers receive higher exposures. Studies link cadmium to kidney dysfunction, bone fractures and cancer.
Tin and its compounds, especially organotins, pose significant health risks ranging from neurological effects to reproductive toxicity. The HMTC program's stringent certification standards aim to minimize these risks and protect consumer health.
