JECFA 64th Meeting (2005) — Cadmium Maximum-Level Impact Assessment and Inorganic Tin Re-evaluation (WHO TRS 930)

The sixty-fourth meeting of the Joint FAO/WHO Expert Committee on Food Additives (Rome, 8-17 February 2005) addressed six agenda compounds, of which two are within scope for Heavy Metal Index: cadmium (Section 3.2, an impact assessment of different proposed Codex maximum levels rather than a re-derivation of the underlying tolerable intake) and inorganic tin (Section 3.4, a re-evaluation of acute and chronic toxicity in the context of canned-food maximum levels). The 64th meeting did not change the cadmium provisional tolerable weekly intake of 7 µg/kg body weight per week (subsequently withdrawn at the 73rd meeting in 2010), nor the inorganic tin PTWI of 14 mg/kg body weight per week (established at the 33rd meeting in 1988). The Committee concluded that an acute reference dose for inorganic tin was inappropriate because gastrointestinal irritation depends on tin concentration and chemical nature in the product rather than on body-weight dose. The non-HMI agenda items (acrylamide, ethyl carbamate, polybrominated diphenyl ethers, polycyclic aromatic hydrocarbons) are out of scope and are not summarized below.

Key numbers

Cadmium — baseline occurrence used in the impact assessment

Cadmium — impact of different maximum levels on mean concentration and intake (Table 6, abbreviated)

Cadmium — intake findings

Inorganic tin — chronic tolerable intake (unchanged at this meeting)

Inorganic tin — acute symptomatic thresholds reaffirmed at this meeting

Inorganic tin — occurrence and dietary intake

Methods (brief)

For cadmium, the Committee carried out a maximum-level impact assessment rather than a new tolerable-intake derivation. For each of seven commodity groups (rice, wheat grain, potatoes, stem/root vegetables, leafy vegetables, other vegetables, and molluscs), a baseline mean cadmium concentration was calculated from all submitted concentration data. The mean was then recalculated after truncating values above each of three candidate maximum levels (proposed, one level higher, and one level lower than proposed), and the percentage reduction from the baseline mean was calculated. The number and percentage of total data points exceeding the ML were also calculated for each candidate. Baseline intakes were estimated from the GEMS/Food regional diets combined with average baseline concentrations of cadmium derived from the new raw data, and intakes were recalculated based on the mean concentration of cadmium after each ML had been applied. For rice and molluscs, the substantial differences across data subsets (rice by region, molluscs by subcategory) required separate evaluations for the relevant subsets: rice was evaluated using European-only data (low estimates) and all-data combined (high estimates); molluscs were evaluated using oyster-only data (low estimates) and all-mollusc data (high estimates). A separate probabilistic intake assessment for cadmium in rice using national data from Japan, considering four different MLs, was also submitted and produced similar conclusions.

For inorganic tin, the Committee’s task was a re-examination of the basis for establishing an acute reference dose, prompted by CCFAC requests at its Thirty-first and Thirty-fifth sessions in connection with proposed draft maximum levels of 200 mg/kg in canned beverages and 250 mg/kg in canned foods other than beverages. The 64th meeting reviewed published acute case series and human controlled-feeding studies on inorganic tin in canned foods and beverages, including a newly available study (Annex 1 reference 24) that spiked tomato juice with tin(II) chloride and dosed human volunteers, plus complementary work on tomato soup with packaging-migrated tin. The Committee considered both the acute symptomatic-threshold question and the basis for the prior chronic PTWI, concluded that the data did not support setting an ARfD because the relevant exposure metric is product concentration rather than body-weight dose, retained the PTWI of 14 mg/kg b.w./week unchanged, and noted that a reassessment of the toxicokinetics and effects of long-term exposure to inorganic tin at concentrations below acute-effect levels would be desirable.

Implications

• Certification: For cadmium, this monograph documents the 64th meeting’s reaffirmation of the 7 µg/kg b.w./week PTWI and the conclusion that the proposed Codex maximum levels would have a very small effect on overall cadmium intake (about 1% of PTWI). It is the primary published source for the impact-assessment percentile arithmetic that informed Codex maximum-level discussions in the 2005-2010 window. The PTWI itself was withdrawn at the 73rd meeting and replaced with the PTMI of 25 µg/kg b.w./month documented in JECFA 73rd; HMTc calibration documentation should treat this 64th-meeting report as the impact-assessment-of-record for the pre-2010 PTWI regime, not as the operative tolerable-intake reference. For inorganic tin, this monograph is the 64th-meeting reaffirmation of the week and of the acute symptomatic thresholds (>150 mg/kg in canned beverages, >250 mg/kg in canned foods); HMTc tin thresholds for canned-product rows should cite both the 33rd-meeting primary derivation and this 64th-meeting reaffirmation.
• Courses: Useful for teaching the distinction between an impact assessment (here, how a particular ML choice changes mean concentration and intake) and a tolerable-intake derivation (the 73rd meeting for cadmium, the 33rd meeting for tin). Also a clean example of why an ARfD is not always appropriate: when acute effects are governed by product-concentration thresholds rather than mg/kg-body-weight dose, the standard ARfD framework does not capture the relevant exposure metric.
• App: Provides defensible occurrence anchors for cadmium in molluscs (oysters mean 1.38 mg/kg, mussels 0.43 mg/kg, other bivalves/cephalopods 0.20 mg/kg) and for the order-of-magnitude difference between Japanese and other-country rice (0.061 vs 0.017 mg/kg). The tin guidance to avoid storing food and beverages in opened tinplated cans is consumer-actionable advice grounded in this monograph.

Provenance notes

License CC-BY-NC-SA-3.0-IGO per WHO standard publication terms. Redistribution permitted non-commercially with attribution and under the same or equivalent license. Heavy Metal Index extracts numerical findings and Committee conclusions as facts and paraphrases narrative content; no verbatim passages of substantial length are reproduced.

The PDF as held in raw/ (SHA-256 fb94852b5c3cc476c779d2378cc7610ca6f9e025d483ebb9c14b6b08875cbbb7) is the official WHO publication (ISBN 92 4 120930 5, ISSN 0512-3054), published by WHO Geneva in 2006 and printed in Singapore. Cover and title-page typography identify “WHO Technical Report Series 930” and the meeting as “Sixty-fourth report of the Joint FAO/WHO Expert Committee on Food Additives.” The Contents lists six agenda compounds: acrylamide, cadmium (impact assessment of different maximum limits), ethyl carbamate, inorganic tin, polybrominated diphenyl ethers, and polycyclic aromatic hydrocarbons.

The 64th-meeting report (TRS 930) is the high-level summary document for the meeting. The detailed toxicological monographs for each agenda compound are published as the companion volume, WHO Food Additives Series 55 (2006), which is a separate primary document not included in this source page. Where this page references “Annex 1 reference 24” for the newly available tomato-juice tin study, the underlying primary paper is the FAS 55 inorganic-tin monograph reference and would need to be ingested separately if its primary data are needed.

Wiki pages this source may touch

• cadmium
• tin
• tin-inorganic
• jecfa-cadmium-ptmi
• codex-cadmium-mls
• codex-cxs-193-1995-tin-canned-foods
• rice
• wheat
• potatoes
• root-vegetables
• leafy-vegetables
• vegetables
• molluscs
• bivalve-molluscs
• canned-foods-general
• canned-tomatoes
• fruit-juices-non-apple

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