EFSA FAF Panel 2022 — Toxic elements in sulfur dioxide–sulfites food additives (E 220–228)
This EFSA scientific opinion is a follow-up re-evaluation of sulfur dioxide–sulfites (E 220–228) as food additives, adopted September 2022. Among other assessments, it includes a risk assessment of toxic elements (As, Pb, Cd, Hg) present in commercial samples of these additives, based on analytical data submitted by interested business operators (IBOs). The Panel concluded that the current EU specification limits for arsenic, lead, and mercury in these food additives should be lowered, and that a new maximum limit for cadmium should be introduced.
Key numbers
Three IBOs submitted analytical data on As, Pb, Cd, and Hg in commercial samples of E 221 (sodium sulfite), E 222 (sodium bisulfite), E 223 (sodium metabisulfite), and E 224 (potassium metabisulfite). The Panel calculated potential consumer exposure to these toxic elements by assuming presence up to the limit value and calculating pro-rata against dietary exposure to the food additives themselves.
For arsenic exposure (expressed as sodium metabisulfite E 223 scenario): at the current EU specification limit, the lower end of the range of calculated margin of exposure (MOE) values was considered insufficient. The Panel recommended lowering the arsenic specification limit based on reported limits of quantification from IBO data, applying a factor of 10.
For Pb, Hg, and Cd: the Panel concluded that their presence at the current or proposed limits would not give rise to safety concern, but recommended lowering the Pb and Hg maximum limits to reflect the lowest achievable concentrations and introducing a new Cd maximum limit — both currently absent from EU Commission Regulation (EU) No 231/2012 specifications.
The existing EU specification maximum limits at the time of opinion: As = 3 mg/kg, Pb = 10 mg/kg, Hg = 1 mg/kg; no Cd limit. The Panel recommended tighter values based on IBO-reported levels (exact proposed numerical limits are documented in Table 4 of the opinion, Section 4.2).
Methods (brief)
Analytical data on As, Pb, Cd, and Hg were submitted by three IBOs for commercial samples of E 221, E 222, E 223, and E 224. Methods were ICP-based; exact analytical methods and LOQ values are reported in Annex H of the opinion. Exposure assessment used EFSA Comprehensive European Food Consumption Database. Two calculation scenarios were applied: (a) expressed as sodium metabisulfite (E 223), considered most typical; (b) expressed as sodium bisulfite (E 222), considered a worst case due to lower SO2 yield.
Implications
Certification: sulfite food additives are used across preserved foods, wines, dried fruits, and processed products. This opinion establishes that As contamination in sulfite additives can contribute meaningfully to dietary As exposure at current specification limits, warranting tighter controls. The recommended introduction of a Cd limit is directly relevant to additive-sourcing specifications.
Courses: illustrates how food additive specifications, not just raw ingredient limits, are part of the heavy metals regulatory framework.
App: food additive ingredients (sulfites) are a contamination vector for As, Pb, Cd, Hg across preserved food categories.