JECFA — Provisional Tolerable Monthly Intake for Cadmium, 25 µg/kg b.w./month
The Joint FAO/WHO Expert Committee on Food Additives established a provisional tolerable monthly intake for cadmium of 25 µg per kilogram body weight per month at its 73rd meeting in 2010 (JECFA 73rd 2010), with the associated 73rd-meeting report published in 2011 as WHO Technical Report Series No. 960. The PTMI is the international health-based reference value for dietary cadmium exposure, chosen on a monthly rather than weekly averaging window specifically to reflect cadmium’s long biological half-life (10 to 30 years in kidney and liver) (JECFA 73rd 2010). It is the reference value against which Codex Alimentarius maximum levels for cadmium are aligned (Codex CCCF17 2024), and against which dietary exposure assessments are routinely expressed as percent-of-PTMI (JECFA 91st 2022).
The 73rd meeting monograph (WHO Food Additives Series No. 64) is the primary published derivation document and is in the corpus (JECFA 73rd 2010). The 91st meeting monograph (WHO Food Additives Series No. 82, 2022) carries the value forward and explicitly attributes it to the 73rd meeting (JECFA 91st 2022).
PTMI value
PTMI parameters from JECFA 73rd 2010 and JECFA 91st 2022:
| Parameter | Value |
|---|---|
| PTMI | 25 µg Cd/kg body weight per month |
| Establishing meeting | JECFA 73rd, 2010 (cadmium addendum published 2011 in WHO Food Additives Series No. 64) |
| Re-examined and carried forward | JECFA 91st meeting, November 2020 (published 2022 as WHO Food Additives Series No. 82) |
| Primary document citing the value to this wiki | 73rd meeting cadmium addendum and 91st meeting monograph |
Approximate weekly-equivalent conversion, for cross-reference to weekly-denominated values such as the EFSA TWI:
| Conversion | Value |
|---|---|
| PTMI expressed as weekly equivalent (25 ÷ (30 ÷ 7)) | approximately 5.83 µg Cd/kg b.w./week |
The weekly-equivalent figure is a derived convenience, not a JECFA-stated value. JECFA’s formal guidance is monthly; the weekly number is provided for comparability only (JECFA 91st 2022).
Critical endpoint
Renal tubular dysfunction biomarkered by urinary β2-microglobulin (JECFA 73rd 2010). The 73rd meeting adopted a biomarker-anchored approach similar in spirit to EFSA’s contemporary methodology, but with different critical-study selection and methodological treatment that produced a numerically higher reference value than the EFSA CONTAM TWI (JECFA 73rd 2010; EFSA Cd 2009). The critical urinary cadmium breakpoint was 5.24 µg Cd/g creatinine and the dietary intake corresponding to the breakpoint at the lower-bound 5th population percentile was 0.8 µg Cd/kg b.w./day, approximately 25 µg/kg b.w./month (JECFA 73rd 2010).
Why monthly rather than weekly
The monograph explicitly attributes the monthly averaging window to cadmium’s long biological half-life (JECFA 73rd 2010). Shorter averaging windows (weekly, daily) implicitly assume that exposure-response dynamics operate on the shorter timescale; for cadmium, with kidney-cortex residency measured in years to decades, a monthly window aligns the regulatory averaging period more closely with the underlying biology. This choice is itself a load-bearing methodological difference with EFSA, which rounds a derived 2.52 µg/kg b.w./week to a 2.5 TWI (EFSA Cd 2009); a weekly expression of the JECFA PTMI (roughly 5.83 µg/kg b.w./week) is approximately 2.3 times the EFSA TWI (JECFA 91st 2022). See synthesis for the full treatment of the EFSA-JECFA divergence.
Dietary exposure relative to the PTMI (from the 91st meeting assessment)
The 91st meeting monograph summarized dietary exposure across reviewed countries as a percentage of the PTMI. National adult mean dietary cadmium exposure from all foods ranged between 9 and 48 percent of the PTMI, corresponding to 2.2 to 12 µg/kg b.w./month (JECFA 91st 2022). European children up to 12 years averaged 47 percent of the PTMI (11.9 µg/kg b.w./month) (JECFA 91st 2022). High-percentile child exposures in Australia and the USA (age 0.5 to 12) reached 82 to 88 percent of the PTMI, or 20.4 to 22.0 µg/kg b.w./month (JECFA 91st 2022). When the 91st meeting’s updated cocoa-product contributions were added to total dietary intake, children in the 0.5 to 12 age range could reach 96 percent of the PTMI (23.9 µg/kg b.w./month), essentially saturating the reference value from dietary sources alone (JECFA 91st 2022).
Adult high-percentile dietary exposures across Europe, Lebanon, and the USA ranged from 6.9 to 12.1 µg/kg b.w./month (28 to 48 percent of PTMI) (JECFA 91st 2022). Major commodity contributors to total mean dietary cadmium exposure across the GEMS/Food regional diets were consistent across prior and current JECFA assessments: rice, wheat, root vegetables, tuber vegetables, leafy vegetables, other vegetables, and molluscs, together accounting for 40 to 85 percent of total mean exposure depending on regional diet (JECFA 91st 2022).
Cocoa and chocolate: the 91st meeting’s new finding
Prior JECFA assessments (including the 77th meeting 2013 cocoa-specific assessment) had not identified cocoa products as major contributors to dietary cadmium (JECFA 91st 2022). The 91st meeting, responding to a request from the 13th session of the Codex Committee on Contaminants in Foods, incorporated expanded 2019 occurrence data for cadmium in cocoa and cocoa-derived products (JECFA 91st 2022). The new data showed higher mean cadmium concentrations in cocoa products than the 77th meeting had recognized, driven in part by a wider geographical range of submitted data. Mean dietary exposure from cocoa products across the 17 GEMS/Food cluster diets (assuming 60 kg body weight) ranges from 0.005 to 0.39 µg/kg b.w./month (0.2 to 1.6 percent of PTMI) (JECFA 91st 2022). The highest high-percentile exposure (P97.5) from cocoa products alone was 12 µg/kg b.w./month, observed in European children aged 7 to 11 consuming cocoa powder specifically (JECFA 91st 2022). Combined with whole-diet exposure estimates, the 91st meeting’s cocoa-inclusive assessment produces total dietary exposures reaching 96 percent of the PTMI in children aged 0.5 to 12, a new finding with direct implications for cocoa supply-chain regulation and for the Codex CCCF process (JECFA 91st 2022).
Relationship to Codex Alimentarius maximum levels
The JECFA PTMI provides the health-based guidance value against which Codex maximum levels are evaluated for health protectiveness (JECFA 91st 2022); feasibility considerations from the Codex Committee on Contaminants in Foods and from national competent authorities determine the specific maximum levels adopted for individual commodity matrices (Codex CCCF17 2024). The 91st meeting’s cocoa exposure finding was prepared specifically to inform the 13th session of CCCF on cadmium in chocolate and cocoa products (JECFA 91st 2022). See codex-cadmium-mls for the matrix-specific Codex maximum levels.
Comparison to other reference values
| Body / Jurisdiction | Value | Basis | Source |
|---|---|---|---|
| JECFA (international, 73rd meeting 2010) | 25 µg/kg b.w./month (≈ 5.83 /week equivalent) | Biomarker-anchored, monthly window for long half-life | JECFA 73rd 2010 |
| EFSA CONTAM (EU, 2009) | 2.5 µg/kg b.w./week | BMDL5-based, urinary B2M biomarker, kinetic back-translation | EFSA Cd 2009 |
| US EPA IRIS (1989, operative) | 1 × 10⁻³ mg/kg/day (food); 5 × 10⁻⁴ mg/kg/day (water) | Significant proteinuria, composite UF 10 | EPA IRIS Cd 1989 |
| US California OEHHA Prop 65 | 4.1 µg/day (oral MADL, developmental toxicity) | Ali 1986 rat developmental study, 1000x statutory safety factor | OEHHA 2001 |
| US ATSDR chronic oral MRL (2012) | 0.1 µg Cd/kg/day | UCDL10 0.5 µg/g creatinine; UF 3 | ATSDR 2012 |
The factor-of-approximately-2.3 gap between the JECFA PTMI (weekly-equivalent 5.83 µg/kg b.w./week) and the EFSA TWI (2.5 µg/kg b.w./week) is substantial and derives from the two bodies’ different methodological choices on overlapping primary literature (JECFA 91st 2022; EFSA Cd 2009). See synthesis for the explicit treatment of this divergence.
Sources
- JECFA 73rd 2010 — JECFA 73rd meeting, 2010 (published 2011). Cadmium addendum, WHO Food Additives Series No. 64 (primary derivation document for the PTMI).
- JECFA 91st 2022 — JECFA 91st meeting, 2020 (published 2022). Cadmium: dietary exposure assessment (WHO Food Additives Series No. 82).
Pending: WHO Technical Report Series No. 960 (2011) summary report companion to the 73rd meeting.