What is E512?
Complete guide to understanding stannous chloride in your food
The Quick Answer
E512 is stannous chloride (tin(II) chloride), used as a color-retention agent and preservative in canned asparagus.
It’s one of the most restrictively used food additives—approved only for a single food product in the European Union.
Most consumers will rarely or never encounter it, as it’s limited to canned asparagus in glass containers.
📌 Quick Facts
- Category: Color Retention Agent & Preservative
- Found in: Canned asparagus (in glass containers) only
- Safety: EFSA-approved, no safety concern identified
- Approved by: EFSA, JECFA (NOT FDA in USA)
- Key Fact: Extremely limited use—only one approved food category
What Exactly Is E512?
E512 is stannous chloride (SnCl₂), also known as tin(II) chloride or tin dichloride.
It’s a colorless or white crystalline solid with a slight odor of hydrochloric acid. The compound is very soluble in water and exists in two forms: anhydrous (no water) and dihydrate (containing two water molecules).
Stannous chloride is synthetically produced and contains tin—a naturally occurring element found in foods, particularly from canning.
In technical terms, it’s a reducing agent and antioxidant used to prevent browning and preserve color in food, particularly asparagus during canning.
Where You’ll Find E512
E512 has the most restrictive approved use of any food additive—it’s limited to ONE specific product:
– Canned asparagus packed in glass containers (maximum 15-20 ppm as tin)
That’s it. No other foods are approved for E512 use in the European Union.
Because of this extreme restriction, most consumers will never consume E512. It’s one of the rarest food additives in commerce.
⚠️ CRITICAL DISTINCTION: Pure stannous chloride in concentrated form is hazardous in industrial settings. However, E512 in food is used at 15-20 ppm (parts per million) in asparagus—millions of times more dilute. The hazards of concentrated tin chloride do NOT apply to food additive use.
How E512 Works in Food
E512 serves two critical functions in canned asparagus:
First, as a color-retention agent: During canning, asparagus can oxidize and discolor, turning brown or gray. Stannous chloride reacts with oxygen before the food can react with it, preventing browning and preserving the characteristic green color of fresh asparagus.
Second, as a preservative: By preventing oxidation, E512 also prevents the formation of undesirable odors and off-flavors that result from oxidative degradation. This extends product quality during storage.
Why Do Food Companies Use E512?
E512 solves a specific aesthetic and quality problem in canned asparagus.
Consumers expect canned asparagus to look fresh and green. Without a color-retention agent like E512, the high-heat canning process inevitably causes oxidative browning. E512 prevents this, making the product more appealing and maintaining consumer expectations for quality.
However, given the extremely narrow use and the fact that EFSA noted “no reply on actual use level…was provided by any interested party” in recent evaluations, E512 may be rarely or never used in modern food production.
Is It Safe?
Regulatory authorities confirm E512 is safe for its approved use.
The EFSA’s comprehensive 2018 re-evaluation explicitly concluded: “The Panel concluded that stannous chloride (E 512) is of no safety concern in this current authorised use and use levels.”
This approval comes with important context: exposure at actual food use levels is far below any level causing adverse effects.
✓ Safety Confirmed: The EFSA found actual exposure from E512 use is below 1.3 μg tin/kg body weight per day—thousands of times below the level that would cause gastrointestinal irritation (40 mg tin).
The EFSA’s 2018 Comprehensive Safety Re-evaluation
The European Food Safety Authority’s thorough 2018 assessment provides authoritative reassurance.
Key findings:
– Mean exposure: BELOW 1.3 μg tin/kg body weight per day (all age groups)
– 95th percentile exposure: 0.0 to 11.2 μg tin/kg bw/day
– No concern with genotoxicity (genetic damage)
– No concern with carcinogenicity (cancer)
– Low absorption from gastrointestinal tract
– Safety verdict: “No safety concern in current authorised use and use levels”
The safety margin is enormous. Actual food exposure is thousands of times below levels associated with any demonstrated adverse effect.
Understanding Tin Safety
Tin is a naturally occurring element found in foods—particularly from canned foods.
Tin from canned foods can be present at 150-250 mg/kg—regulatory limits specifically set to prevent gastrointestinal irritation. These limits are hundreds of times higher than E512 use levels.
JECFA established a Provisional Tolerable Weekly Intake (PTWI) of 14 mg/kg body weight for tin—an exceptionally conservative limit. Food additive use of E512 represents only a tiny fraction of total dietary tin exposure and is far below this limit.
Gastrointestinal Irritation—The Only Identified Concern
The sole identified adverse effect of tin at high doses is gastrointestinal irritation.
In humans, gastrointestinal irritation (nausea, abdominal cramps, vomiting, diarrhea) occurs only after a bolus dose of 40 mg tin. This is an acute effect at high concentrations—not from chronic low-level food exposure.
At actual food additive use levels (below 1.3 μg/kg bw per day), this effect is completely absent. The exposure is thousands of times lower.
Occupational Hazards—Not Relevant to Food Use
In industrial settings, concentrated stannous chloride can cause hazards—but these don’t apply to food.
Concentrated pure stannous chloride in occupational settings can cause:
– Skin and eye irritation/burns
– Respiratory tract irritation
– Pulmonary damage at extreme exposures
However, these hazards are for industrial workers handling concentrated powder or solution. Food-grade E512 is used at 15-20 parts per million in asparagus—a completely different scenario. The hazards of concentrated tin chloride do NOT apply to food additive use.
Why Such Restrictive Use?
E512’s extremely narrow approval (only canned asparagus in glass) reflects a conservative regulatory approach.
Rather than limiting E512 based on safety (which EFSA confirms is excellent), the restriction appears to be precautionary and practical. Glass containers are specified likely because tin can leach into acidic foods from metal containers, but this is a separate concern from direct additive use.
Actual Use Status
An important practical note: E512 may not be used at all in modern food production.
In its 2018 re-evaluation, EFSA noted that “no reply on the actual use level of stannous chloride (E 512) as a food additive…was provided by any interested party.” This suggests manufacturers may not be using E512, even though it remains technically approved.
If E512 isn’t being used in food, the question of its safety becomes entirely theoretical.
Manufacturing
E512 is synthetically produced through controlled chemical synthesis.
Tin and chlorine are combined in precise controlled conditions to create stannous chloride. Food-grade material must meet strict purity and specification standards.
Regulatory Status by Region
E512 approval varies by region:
– European Union: Approved only for canned asparagus in glass (25 mg Sn/kg maximum)
– United States (FDA): NOT approved
– JECFA (International): Approved with historical PMTDI of 2 mg/kg bw
The fact that it’s not approved in the USA but is in the EU reflects different regulatory philosophies and different assessment timelines.
Vegan, Vegetarian, and Allergen Status
E512 is suitable for:
– Vegan diets ✓
– Vegetarian diets ✓
– Gluten-free diets ✓
Tin is a mineral element with no animal products or byproducts involved in production.
The Bottom Line
E512 (stannous chloride) is a color-retention agent approved only for canned asparagus in glass containers in the European Union.
The EFSA’s 2018 re-evaluation explicitly confirmed “no safety concern in current authorised use and use levels.”
Actual exposure from approved use is below 1.3 μg tin/kg body weight per day—thousands of times below any level demonstrating adverse effects.
Most importantly, E512 may not be used at all in modern food production, despite remaining technically approved. EFSA found industry provided no data on actual use in recent evaluations.
Most consumers will never encounter E512 because it’s limited to a single food product in a single region (EU canned asparagus in glass).
As always, food labels must declare E512 when used, enabling informed consumer choice.