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A stainless-steel saucepan, cast-iron skillet and copper-colored pot illustrating fellows2025 metal cookware lead exposure research context.

Evaluating metal cookware as a source of lead exposure

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Overview

Fellows and colleagues screened 44 metal cookware items purchased from US online retailers or donated by Afghan-heritage families using X-ray fluorescence and a novel acetic acid leaching method. The study builds on a prior round of 40 aluminum cookware pieces and finds that all 15 aluminum items tested exceeded the FDA Interim Reference Level (IRL) for children of 2.2 micrograms per day. Indian hindalium/indolium alloy cookware contained hundreds to thousands of parts per million lead as an intentional alloy component; brass items showed the highest leachate concentrations. All 17 stainless steel items tested yielded lead leachate below the child IRL. The paper establishes commercially available aluminum and brass cookware as a recognized but inadequately regulated source of lead exposure that directly affects food consumed by children.

Key numbers

XRF screening (Table 1, ppm median and range, selected items):

  • Kadai (Indian fry pan/wok, Pot 51): median lead (Pb) 5049 ppm, range 128 to 47,191 ppm
  • Appam pan (Indian frying pan, Pot 54): median Pb 716 ppm, range 603 to 794 ppm
  • Afghan pressure cooker (Pot 93): median Pb 538 ppm, range 0 to 48,183 ppm
  • Afghan pressure cooker (Pot 94): median Pb 605 ppm, range 0 to 64,852 ppm
  • Brass tope (Pot 100): median Pb 3611 ppm, range 2859 to 4585 ppm
  • Caldero, Colombian food-grade aluminum alloy (Pot 57): median Pb 8 ppm (greater than 50% of measurements below LOD; value = 8th percentile)
  • US stock pots (Pots 80 to 84, 87): median Pb 0 to 11 ppm (mostly below LOD)
  • Stainless steel items (n=17): all Pb “much lower levels” than aluminum items; no child IRL exceedances reported

Lead leachate doses (Table 1, boiling 5% acetic acid 15 min and 24 h, 250 mL):

  • Appam pan (Pot 54): 15-min dose 3.6 micrograms/250 mL; 24-h dose 232 micrograms/250 mL (exceeds child IRL of 2.2 micrograms/day by approximately 1,400-fold at 24 h)
  • Kadai (Pot 51): 15-min dose 192 micrograms/250 mL; 24-h dose 335 micrograms/250 mL
  • Kadai (Pot 55): 15-min dose 6.13 micrograms/250 mL; 24-h dose 263 micrograms/250 mL
  • Brass tope (Pot 100): 15-min dose 1430 micrograms/250 mL; 24-h dose 2700 micrograms/250 mL
  • Afghan pressure cooker (Pot 93): 15-min dose 48.5 micrograms/250 mL; 24-h dose 990 micrograms/250 mL
  • Caldero (Pot 57): 15-min dose 0.23 micrograms/250 mL; 24-h dose 4.63 micrograms/250 mL
  • US stock pot (Pot 83): 15-min dose 0.0355 micrograms/250 mL; 24-h dose 0.175 micrograms/250 mL

Population-level finding: 27 of 40 aluminum cookware items in the prior study round exceeded the FDA child IRL of 2.2 micrograms/day. All 15 aluminum items in this round exceeded it.

Regulatory benchmarks: FDA IRL for children 2.2 micrograms/day; FDA IRL for adults 8.8 micrograms/day; CDC blood lead reference value for children 3.5 micrograms/dL.

Methods (brief)

XRF screening used portable X-ray fluorescence (model not stated) on the cookware surface. Leaching used a novel method: 250 mL of 5% acetic acid was brought to boiling in the cookware for 15 minutes, then the leachate was collected; a separate 24-hour soak was also run. Lead concentrations in leachates were measured by an unspecified trace-metal method (methods section not fully transcribed). The 5% acetic acid at boiling temperature represents an acidic food scenario. Stainless steel was tested only by XRF and leachate comparison; full tabular data for stainless steel leachate concentrations are not reported in the paper beyond the qualitative statement that all were below the child IRL. CRM and recovery details are not reported.

Implications

Certification: This source provides direct evidence that commercially available metal cookware, including items sold on major US online retail platforms, can leach lead into food at concentrations exceeding the FDA child IRL by orders of magnitude. The finding is directly relevant to any certification category involving food preparation vessels used in households with young children, though this paper documents adult cookware, not child-sized items. Food prepared in these pans is a child exposure pathway.

Courses: Demonstrates the gap between XRF screening (surface bulk content) and actual food migration, and how alloy type (hindalium/indolium vs food-grade aluminum vs stainless steel) drives exposure magnitude. The appam pan example (1,400-fold child IRL exceedance) is a vivid teaching illustration.

App: Supports a product-context signal that aluminum and brass cookware of Indian, Afghan, or unverified South/Central American origin may carry elevated lead and should be a priority for XRF testing before household use.

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