Overview
The EFSA ANS Panel re-evaluated the safety of stannous chloride (E 512; CAS 10025-69-1 for the dihydrate) for continued authorization as a food additive in the EU. E 512 is authorized in only one EU food category (04.2.3: canned or bottled fruits and vegetables), specifically for white asparagus only, at a maximum permitted level (MPL) of 25 mg tin (Sn) per kg. The Panel concluded that E 512 is of no safety concern at current authorized use and use levels, using a dose-based comparison to the JECFA PMTDI for inorganic tin as the reference rather than establishing a new ADI. The evaluation assessed only stannous chloride (Sn2+, inorganic tin(II)); organotin compounds were explicitly excluded from scope.
Key numbers
Reference values for inorganic tin (from prior evaluations, adopted in this opinion):
| Reference | Value | Species | Basis |
|---|---|---|---|
| JECFA PMTDI (1988) | 2 mg/kg bw/day | inorganic Sn, contaminant | Based on gastric irritancy threshold of ~200 mg/kg in food |
| JECFA PTWI (1988) | 14 mg/kg bw/week | inorganic Sn, contaminant | Same basis; 7 x PMTDI |
| NOAEL (90-day rat study) | 63 mg/kg bw/day | stannous chloride | Reduction in body weight gain and haemoglobin; species and study reference not specified beyond “90-day study” in the visible summary |
| Human bolus threshold | 40 mg Sn per bolus dose | stannous chloride | Gastric irritation reported; concentration in food equivalent approximately 200 mg/kg (basis of JECFA 1982 PMTDI) |
| EFSA NDA 2006 | No tolerable upper intake level (UL) established | inorganic Sn | Data insufficient |
Authorized use of E 512 in EU:
| Food category | Product | MPL (mg Sn/kg) |
|---|---|---|
| 04.2.3 | White asparagus (canned or bottled) | 25 |
No other food categories are authorized for E 512 use in the EU. No actual use data were submitted by industry to this re-evaluation (no products labelled as containing E 512 were found in Mintel GNPD database searches from January 2013 to April 2018 in EU and Norwegian markets).
MPL-based dietary exposure estimates for E 512 (conservative maximum; E 512 assumed to equal 25 mg Sn/kg in all consumption of food category 04.2.3):
| Population group | Mean exposure (µg Sn/kg bw/day) | P95 exposure (µg Sn/kg bw/day) |
|---|---|---|
| Toddlers (12-35 months) | below 1.3 | 0.0 to 11.2 (varies by country) |
| Children (3-9 years) | below 1.3 | 0.0 to 11.2 (varies by country) |
| Adolescents (10-17 years) | below 1.3 | 0.0 to 11.2 (varies by country) |
| Adults (18-64 years) | below 1.3 | 0.0 to 11.2 (varies by country) |
| Elderly (65+ years) | below 1.3 | 0.0 to 11.2 (varies by country) |
The Panel concluded that even this conservative MPL-based scenario generates mean exposures well below the JECFA PMTDI of 2,000 µg/kg bw/day (by a factor of more than 1,000), and P95 exposures well below the PMTDI even at the highest national P95 value of 11.2 µg Sn/kg bw/day. The exposure from E 512 use in white asparagus is stated as not of safety concern.
Evidence Fitness
Strong occurrence evidence for the regulatory framework governing E 512 (stannous chloride as food additive) and for the reference toxicological values used by EFSA and JECFA for inorganic tin. The exposure estimates are MPL-based worst-case modelling from regulatory authorization data, not measured food concentrations. The NOAEL and human bolus threshold are from prior evaluations adopted by the Panel without re-derivation. This source is authoritative for the EU regulatory authorization of stannous chloride and for the JECFA PMTDI/PTWI reference values.
Methods
Exposure modelling used the EFSA Comprehensive European Food Consumption Database, Tier 2 deterministic modelling with MPL-based concentrations (25 mg Sn/kg applied to all consumption of food category 04.2.3). Actual use survey: Mintel GNPD database searches from January 2013 to April 2018 in EU and Norwegian markets found no products labelled as containing E 512.
Scope is explicitly limited to stannous chloride (inorganic tin, Sn2+). Organotin compounds are not addressed. The evaluation covers E 512 as a food additive (technological function: color stabilizer in white asparagus) rather than as a contaminant from tinplate migration.
Implications
- Certification: confirms JECFA PMTDI of 2 mg/kg bw/day and PTWI of 14 mg/kg bw/week as the operative regulatory reference values for inorganic tin; confirms no EU-wide concern about E 512 use at MPL levels. The human bolus irritancy threshold (40 mg Sn, equivalent to approximately 200 mg/kg in food) is the key dose-response anchor for acute gastrointestinal effects.
- Courses: illustrates the distinction between inorganic tin as food additive (white asparagus only, low-volume use) versus inorganic tin as food contaminant from tinplate migration (the dominant dietary tin pathway).
- App: E 512 use in white asparagus is minimal; the additive contribution to dietary tin is negligible relative to tin migration from tinplate canned food.
- Microbiome: not addressed in this opinion.
Provenance notes
Open access under CC BY-ND license (EFSA standard). Retrieved from PMC as PMC7009391. EFSA Journal opinion, DOI 10.2903/j.efsa.2018.5295.
Related evidence
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