What is E213?
Complete guide to understanding E213 (Calcium Benzoate) in your food
The Quick Answer
E213 is calcium benzoate, the calcium salt of benzoic acid, used as a synthetic preservative to inhibit growth of mold, yeast, and some bacteria—particularly in acidic foods and beverages.
It’s the calcium salt version of benzoic acid preservatives (E210-E213 family), selected when calcium provision is desired or where superior solubility is needed in food formulations.
Most people consuming soft drinks, fruit juices, pickled foods, baked goods, and sauces regularly encounter E213, though it remains largely invisible—functioning as a preservative with good safety record but similar conditional concerns as sodium benzoate (potential benzene formation with vitamin C under certain conditions).
📌 Quick Facts
- Category: Synthetic Preservative, Benzoate Compound, Calcium Salt, Antimicrobial Agent
- Source: Fully synthetic—calcium salt of benzoic acid
- Found in: Soft drinks, fruit juices, baked goods, pickles, sauces, jams, beverages, soy products
- Safety: FDA GRAS approved; EFSA approved; JECFA approved; ADI 0-5 mg/kg bw for benzoate group
- Natural or Synthetic: Fully synthetic (though benzoic acid occurs naturally in trace amounts)
- Vegan/Vegetarian: Yes
- Key Concern: Like sodium/potassium benzoates, potential benzene formation when combined with vitamin C under heat/light; pH-dependent effectiveness; rare asthma/sensitivity in susceptible individuals
- Chemical Formula: Ca(C₇H₅O₂)₂; calcium salt of benzoic acid
What Exactly Is It?
E213 is calcium benzoate, the calcium salt of benzoic acid with the molecular formula Ca(C₇H₅O₂)₂ and molecular weight of 282.31 g/mol.
Calcium benzoate is created by neutralizing benzoic acid with calcium hydroxide or calcium carbonate. The compound is one of four benzoate salt preservatives (E210 benzoic acid, E211 sodium benzoate, E212 potassium benzoate, E213 calcium benzoate). The chemical structure is identical except for the calcium cation replacing sodium or potassium—making it functionally equivalent in most applications.
Physically, E213 appears as a white crystalline powder. It is soluble in water (approximately 300-400 g/L at 20°C—better soluble than other benzoates), making it suitable for aqueous food systems. The compound is heat-stable and maintains preservative activity across moderate pH ranges (pH 2-8), though most effective in acidic conditions (pH below 4.5).
Chemically, calcium benzoate functions identically to benzoic acid and sodium benzoate. Upon dissociation in acidic solutions, benzoic acid is released, which enters microbial cells and inhibits microbial growth by disrupting cellular respiration and metabolic processes.
Where You’ll Find It
E213 appears in a wide range of acidic foods and beverages:
• Soft drinks and carbonated beverages
• Fruit juices and juice drinks
• Baked goods (bread, cakes, pastries)
• Pickles and pickled vegetables
• Sauces and condiments
• Jams and jellies
• Soy milk and soy products
• Soy sauce and vinegar
• Low-sugar fruit preserves
• Olives and olive-based products
• Fish and seafood products
• Salad dressings
• Beverages (tea concentrates, low-alcoholic beverages)
• Dairy-based desserts
• Chewing gum
• Liquid dietary supplements
• Mustard and spice preparations
E213 is particularly common in beverages and baked goods where its superior solubility and stability make it preferred over other benzoate salts.
Why Do Food Companies Use It?
E213 performs one critical function, selected particularly for its solubility and calcium provision:
Antimicrobial preservation with superior solubility: E213 calcium benzoate inhibits mold, yeast, and some bacteria growth—extending shelf life in beverages and acidic foods. The compound’s superior water solubility (compared to benzoic acid E210) makes it ideal for aqueous formulations. Additionally, calcium provision appeals to manufacturers seeking product calcium enrichment or to consumers monitoring calcium intake.
Why calcium benzoate instead of sodium/potassium salts: Calcium benzoate is selected when: (1) calcium fortification is desired, (2) sodium reduction is important (unlike E211 sodium benzoate or E212 potassium benzoate), or (3) superior solubility in aqueous systems is needed. The calcium cation provides functional benefit beyond preservation.
Is It Safe?
E213 calcium benzoate is officially approved with good safety record, but with similar conditional concerns as sodium benzoate—potential benzene formation when combined with vitamin C.
Regulatory Status:
• FDA (USA): Generally Recognized As Safe (GRAS); recognized as having same function as sodium benzoate
• EFSA (Europe): Approved as direct food additive (E213); part of benzoate group (E210-E213) with group ADI 0-5 mg/kg bw
• JECFA (WHO/FAO): Approved; ADI 0-5 mg/kg body weight (expressed as benzoic acid)
⚠️ CONDITIONAL SAFETY CONCERN—BENZENE FORMATION (SAME AS E212): The primary safety concern with E213 is identical to E212 potassium benzoate:
• Benzene formation mechanism: When calcium benzoate coexists with ascorbic acid (vitamin C) in beverages, exposure to heat and light can cause decarboxylation reaction producing benzene—a known carcinogen
• Conditions required: Simultaneous presence of: (1) calcium benzoate, (2) vitamin C, (3) heat exposure, (4) light exposure
• Regulatory stance: FDA stated benzene levels formed in beverages (0-5 ppb) “will not pose a safety concern” as they remain at or below safe drinking water limits (5 ppb)
• Consumer concern remains valid: While regulatory authorities maintain safety, theoretical possibility of benzene formation persists—particularly in products stored in warm conditions
• Avoidance strategy: Choose beverages NOT combining benzoate preservatives with vitamin C, or ensure cool/dark storage to minimize heat/light exposure
Additional safety considerations:
• At food-use levels: No documented adverse effects; safe for general population
• Benzoate sensitivity: Rare; some individuals (particularly asthmatic) may experience asthma-like symptoms or hives; extremely rare true allergies
• Infant safety: Not allowed in infant/young children products per some regulatory guidelines
• Pregnancy: No reproductive toxicity documented; safe at approved levels
• High-dose effects: Only at excessive doses (far exceeding food-use levels): gastric irritation, vomiting, liver/kidney damage
• Drug interactions with colorings: Some evidence that benzoates combined with azo colorings (E102-E110) may promote hyperactivity in susceptible children (ADHD-like symptoms)
• Effectiveness limitation: Only effective in acidic conditions (pH <4.5); ineffective in neutral/alkaline products
Benzoate Family Overview
E213 calcium benzoate is one of four benzoate preservatives (E210-E213):
• E210 (Benzoic acid): Free acid form; least soluble; antimicrobial function
• E211 (Sodium benzoate): Sodium salt; most commonly used benzoate; identical function to E213
• E212 (Potassium benzoate): Potassium salt; identical function; selected for potassium provision or sodium reduction
• E213 (Calcium benzoate): Calcium salt; superior solubility; most widely used benzoate in some applications; provides calcium
All four function identically in preservation; selection depends on desired cation and solubility requirements.
Production Method
E213 calcium benzoate is produced through simple chemical synthesis:
1. Benzoic acid is synthesized through toluene oxidation (most common industrial route): C₆H₅CH₃ + oxidation → C₆H₅COOH + H₂O
2. The benzoic acid is dissolved in water
3. Calcium hydroxide or calcium carbonate is added, neutralizing the benzoic acid: 2 C₆H₅COOH + Ca(OH)₂ → Ca(C₇H₅O₂)₂ + 2 H₂O
4. Calcium benzoate crystallizes from solution
5. The product is filtered, washed, dried, and standardized for purity
All production is fully synthetic—no natural sources exist. Food-grade E213 requires purification from industrial synthesis.
Natural vs Synthetic Version
E213 is entirely synthetic—there is no natural version.
While benzoic acid occurs naturally in trace amounts in some berries and foods, commercial E213 calcium benzoate is entirely synthetically produced. All food-grade calcium benzoate is created through chemical synthesis from petroleum-derived toluene.
Comparison with Related Preservatives
E213 calcium benzoate occupies a position among benzoate and sorbate preservatives:
• E210 (Benzoic acid): Same function; free acid form; less soluble
• E211 (Sodium benzoate): Identical function; most common benzoate; sodium content
• E212 (Potassium benzoate): Identical function; potassium provision; less soluble than E213
• E213 (Calcium benzoate): Identical function; most soluble benzoate; calcium provision; most widely used
• E200 (Sorbic acid): Different chemical; broader spectrum; effective at wider pH range
• E202 (Potassium sorbate): Sorbate equivalent; broader antimicrobial spectrum; more pH-independent
• E234 (Nisin): Natural bacteriocin; different mechanism; more expensive
• E235 (Natamycin): Natural antifungal; surface application; antifungal focus
E213’s primary advantage over other benzoates is superior solubility; its limitation is pH dependence (effective only pH <4.5).
Calcium Benzoate vs Other Benzoates—Market Leadership
E213 calcium benzoate is the most widely used benzoate preservative:
Superior solubility in water compared to E212 (potassium benzoate) and E210 (benzoic acid) makes E213 the preferred choice for aqueous formulations. Additionally, calcium provision appeals to manufacturers and consumers, giving E213 competitive advantage over E211 (sodium benzoate) in applications where sodium reduction or calcium fortification is important.
Environmental and Sustainability
E213 calcium benzoate production from petroleum-derived toluene carries environmental costs. The compound is readily biodegradable and poses minimal environmental toxicity once in ecosystems. Environmental impact is comparable to other synthetic benzoates—moderate concern in context of industrial manufacturing.
Natural Alternatives
Want to avoid E213? Alternatives for beverage and acidic food preservation include:
• E200 (Sorbic acid): Broader spectrum; effective at wider pH range; natural or synthetic
• E202 (Potassium sorbate): Sorbate equivalent; broader effectiveness; documented gut microbiome effects
• E234 (Nisin): Natural bacteriocin; antibacterial; excellent safety
• E235 (Natamycin): Natural antifungal; surface treatment; excellent safety
• Acetic acid/vinegar: Natural preservative; different sensory profile
• Citric acid: Natural acidulant; provides acidity for preservation
• Lactic acid: Natural fermentation byproduct; acidulant/preservative
• Essential oils: Natural antimicrobials; variable efficacy; sensory impact
• No chemical preservative: Accept shorter shelf life; faster distribution
Consumer Actions to Minimize E213 Exposure/Concern
For consumers concerned about E213 or benzene formation:
• Avoid beverages combining E213 (or other benzoates E211, E212) with vitamin C
• Check labels: if calcium benzoate AND ascorbic acid both listed, avoid or ensure cool/dark storage
• Choose beverages preserved with sorbates (E200-E202) instead
• Select natural-preserved products (citric acid, essential oils)
• Prefer short-shelf-life products with minimal preservatives
• Store beverages in cool, dark conditions to minimize any theoretical benzene formation
• Reduce overall soft drink consumption (general health benefit independent of E213)
The Bottom Line
E213 (calcium benzoate) is a fully synthetic preservative approved by FDA, EFSA, and JECFA with good safety record at food-use levels, but with the same conditional concern as E212—potential benzene formation when combined with vitamin C under heat/light exposure.
E213 is the calcium salt of benzoic acid, functioning identically to sodium benzoate (E211) and potassium benzoate (E212). It inhibits mold, yeast, and some bacteria growth—effective primarily in acidic foods and beverages (pH below 4.5). The compound’s superior solubility compared to other benzoate salts makes it the most widely used benzoate preservative.
The primary regulatory and consumer concern is identical to E212 potassium benzoate—potential benzene formation when coexisting with vitamin C in beverages exposed to heat and light. FDA maintains that benzene levels (0-5 ppb) remain below safe drinking water standards, but the theoretical possibility has driven industry awareness and consumer preference for alternatives.
E213’s key functional advantage is superior solubility—making it ideal for aqueous food systems. Its key functional limitation is pH dependence—effective only in acidic conditions (pH below 4.5), unsuitable for neutral/alkaline products. This has driven some adoption of broader-spectrum sorbates.
The calcium provision is a secondary benefit—distinguishing E213 from sodium benzoate (E211), appealing to manufacturers and consumers monitoring sodium intake or seeking calcium enrichment.
For consumers, E213 represents a widely used preservative with documented safety at approved levels but with one specific avoidance strategy: do not consume beverages combining benzoate preservatives with vitamin C that will experience warm storage. Alternatively, choosing beverages preserved with sorbates or natural preservatives eliminates this specific theoretical concern.