EFSA FAF Panel 2022 — Heavy metals in food additive E 422 (glycerol)
The EFSA Panel on Food Additives and Flavourings assessed data submitted by interested business operators on the levels of arsenic, lead, cadmium, and mercury in 18 commercial glycerol (E 422) samples as part of a follow-up re-evaluation to update EU specifications. All 18 samples had all four toxic elements below detection limits (LOD range: As 0.02–0.43 mg/kg; Pb 0.02–0.14 mg/kg; Cd 0.02–0.1 mg/kg; Hg 0.005–0.19 mg/kg). The Panel found that at the current EU specification limits (As 3 mg/kg, Pb 2 mg/kg, Hg 1 mg/kg, Cd 1 mg/kg) potential exposure to these toxic elements from glycerol use would raise concerns, particularly for lead (MOE < 1 at maximum allowed concentration) and arsenic (insufficient MOE), and concluded that the maximum limits in EU specifications for all four elements should be lowered to reflect actual achievable commercial levels.
Key numbers
- n=18 commercial E 422 (glycerol) samples; all results below LOD for all four toxic elements
- LOD ranges: As 0.02–0.43 mg/kg; Pb 0.02–0.14 mg/kg; Cd 0.02–0.1 mg/kg; Hg 0.005–0.19 mg/kg
- Analysis by ICP-MS and/or ICP-OES
- Current EU specification limits (Commission Regulation (EU) No 231/2012): Pb 2 mg/kg, As 3 mg/kg, Cd 1 mg/kg, Hg 1 mg/kg
- At current limits, risk assessment: MOE for Pb = 0.81 at 308 mg/kg bw/day E 422 exposure (toddlers, mean); MOE < 1 is of concern
- At current limits, Hg represents 54% of TWI (toddlers mean), Cd represents 86% of TWI
- At current limits, MOE for As = 0.32–8.7 (lower bound inadequate)
- Scenarios based on highest reported LOD: Pb MOE 8.12, Hg 10.8% of TWI, Cd 8.6% of TWI, As MOE 1.9–52 (still insufficient for As)
- Panel conclusion: lower all four specification limits; As insufficient MOE persists even at reduced levels
Methods (brief)
Risk assessment based on commercial sample analytical data submitted by one interested business operator. ICP-MS and/or ICP-OES analysis; no LOQs reported. EFSA performed three exposure scenarios: (i) at current EU specification limits; (ii) at highest reported LOD; (iii) at lowest reported LOD multiplied by 10. Exposure estimates derived from re-evaluation dietary survey data across six population groups (infants, toddlers, children, adolescents, adults, elderly) using non-brand-loyal scenario; highest reference population used was toddlers (mean 308, p95 460 mg/kg bw/day E 422 from all authorized food uses).
Implications
Certification: Demonstrates that actual commercial glycerol (E 422) contains essentially no detectable heavy metals, but that the current EU specification limits are set too high relative to what is achievable and safe. Relevant for ingredient specification review when glycerol appears in certified products (e.g., protein bars, confectionery). Courses: Excellent EFSA risk assessment case study; illustrates the gap between current regulatory limits and what the achievable commercial baseline actually is for food additive impurities. App: Glycerol as a food additive is a low-contamination pathway for As, Pb, Cd, Hg at commercial quality levels; risk is at specification limit, not at actual measured levels.