What is E1518?

Complete guide to understanding E1518 (Glycerol Triacetate/Triacetin) in your food

The Quick Answer

E1518 is glycerol triacetate (also called triacetin or triacetyl glycerol)—a synthetic ester obtained by acetylation of glycerol’s three hydroxyl groups. It’s an oily liquid used in food as a humectant (moisture retainer), plasticizer (texture softener), flavor carrier/solvent, and stabilizer.

It’s used in food primarily to retain moisture, carry and distribute flavorings, improve texture, extend shelf life, and soften products—found in chewing gum (primary use), baked goods, candies, confectionery, flavored beverages, and other processed foods.

E1518 is FDA GRAS approved and authorized in the EU for specific applications (as carrier for flavorings up to 3 g/kg; unlimited in chewing gum). It’s safe at approved food use levels with no documented adverse effects.

What Exactly Is It?

E1518 is glycerol triacetate (C₉H₁₄O₆), a synthetic ester created by acetylation of glycerol—attaching three acetate groups to glycerol’s three hydroxyl groups. It’s a colorless, oily, viscous liquid with a faint characteristic odor.

Think of it as glycerol (a naturally sweet, viscous liquid) with three acetate “coats” added to it. This chemical modification creates a compound with different properties: more lipophilic (fat-loving), better solvency for flavorings, and enhanced plasticizing properties.

Key characteristic: The acetate groups make triacetin an excellent solvent for lipophilic (fat-soluble) flavorings and fragrances, while its glycerol core provides hygroscopic (water-absorbing) properties—making it useful for both flavor carrier and moisture retention.

Chemical composition:

• Molecular formula: C₉H₁₄O₆
• IUPAC name: 1,2,3-Propanetriol triacetate
• CAS Number: 102-76-1
• Molecular weight: 218.21 g/mol
• Density: 1.154-1.158 g/cm³
• Melting point: −78°C (very low—remains liquid at cold temperatures)
• Boiling point: 258-259°C (very high—useful for solvent applications)
• pH: 5.0-6.0 at 50 g/L in water

How it’s made:

E1518 is produced by acetylating glycerol with acetic acid or acetic anhydride:

• Basic process: Glycerol (C₃H₈O₃) + 3 Acetic acid (CH₃COOH) → Triacetin (C₉H₁₄O₆) + 3 Water (H₂O)
• Catalyst: Reaction typically uses acid catalyst or enzymes
• Alternative method: Glycerol reacted with acetic anhydride (more efficient)
• Glycerol source: Can be petroleum-derived or vegetable-derived (from biodiesel production or food processing)

Natural components: Both building blocks (glycerol and acetic acid) occur naturally. Glycerol is a sweet, viscous liquid found in fats. Acetic acid is the main component of vinegar. However, the final triacetin is synthetically manufactured.

Where You’ll Find It

E1518 appears in a specialized range of food and industrial products:

• Chewing gum (PRIMARY USE) – plasticizer for texture, keeps gum soft and chewable
• Baked goods and pastries – humectant for moisture retention, prevents staling
• Candy and confectionery – texture improvement, moisture retention
• Chocolate products – texture softening, flavor carrier
• Flavorings and flavor compounds (as solvent/carrier for fragrant oils)
• Sweetened beverages and soft drinks – flavor carrier
• Liqueurs and alcoholic beverages – flavor carrier and enhancer
• Cosmetics – humectant, plasticizer, solvent (widespread use)
• Pharmaceuticals – excipient in capsules, tablets, liquids (humectant, plasticizer, solvent)
• Food packaging – plasticizer in food-contact plastics
• Cigarette filters – plasticizer for maintaining texture and moisture

Regulatory use scope: EU Authorization—E1518 authorized as carrier for other food additives (flavorings) up to 3 g/kg maximum; unlimited in chewing gum. FDA GRAS status—Generally Recognized As Safe for use in human food at all permitted levels.

Primary food application: E1518 is most iconic in chewing gum, where it functions as the plasticizer that keeps gum soft, flexible, and chewable without being sticky or hardening.

Why Do Food Companies Use It?

E1518’s primary function is serving as a plasticizer and humectant—softening products while retaining moisture.

Food manufacturers use triacetin for multiple strategic advantages:

• Plasticizer (in chewing gum): Keeps gum soft, flexible, and chewable; prevents hardening
• Humectant: Absorbs and retains moisture; prevents drying out of baked goods
• Flavor carrier/solvent: Dissolves and carries lipophilic (fat-soluble) flavorings and fragrances; enables even distribution
• Shelf life extension: Moisture retention slows staling and degradation
• Texture improvement: Softens products; improves palatability and mouthfeel
• Stabilizer: Maintains product consistency and texture during storage
• Emulsifier: Improves mixing of incompatible ingredients
• Antifungal preservation: Fungistatic properties through release of acetic acid
• Processing aid: Improves manufacturing efficiency; enables uniform incorporation of difficult-to-dissolve ingredients
• Sweetness perception: Can enhance sweetness perception of other ingredients
• Cost efficiency: Effective at low concentrations; reduces need for other additives
• Regulatory universality: Approved worldwide with recognized safety status
• High boiling point: Doesn’t volatilize during processing; remains stable

Unique advantage in chewing gum: E1518 is nearly irreplaceable in chewing gum manufacturing—no other single compound provides the specific combination of plasticizing effect, flavor solubility, and texture preservation that triacetin offers.

Is It Safe?

E1518 is safe at approved food use levels and has been extensively approved by regulatory authorities.

Regulatory approval:

• FDA approved: Generally Recognized As Safe (GRAS) for use in human food; included in SCOGS database since 1975
• EU authorized: Approved as food additive E1518 for specific uses (flavorings carrier up to 3 g/kg; unlimited in chewing gum)
• JECFA recognized: Recognized as safe food additive
• Food Standards Australia New Zealand: Approved
• International approval: Approved by regulatory bodies worldwide

Safety profile:

• No acute toxicity: No documented toxicity at food use levels
• No chronic toxicity: Long-term exposure at approved levels shows no harm
• No documented adverse effects: No adverse health effects documented in any population
• No carcinogenicity: No evidence of cancer-causing potential
• No reproductive/developmental effects: Safe for pregnancy and breastfeeding
• No genotoxicity: No evidence of genetic damage
• Metabolism: Metabolized to glycerol and acetic acid, both normal dietary components
• Rapid metabolism: Efficiently broken down and excreted
• No bioaccumulation: Does not accumulate in tissues
• Long history of safe use: FDA GRAS status since 1975 (50+ years of food use)
• Pharmaceutical use: Approved as pharmaceutical excipient in medications and supplements
• Cosmetic use: Long-established history in cosmetics (demonstrates safety profile)
• Inhalation safety: FDA confirms non-toxic when used properly; prolonged inhalation of vapors should be avoided (typical precaution)

SCOGS Assessment (1975): The FDA Select Committee On GRAS Substances (SCOGS) reviewed triacetin in 1975 and concluded it was safe. This assessment has never been contradicted or revised.

Natural vs Synthetic Version

E1518 is synthetically produced but derived from natural-origin components:

Source and production:

• Glycerol source: Petroleum-derived or vegetable-derived (from biodiesel production, food processing, soap manufacturing)
• Acetic acid source: Petroleum-derived or fermentation-derived (from vinegar fermentation)
• Synthesis: Chemical acetylation of glycerol with acetic acid or acetic anhydride
• Final product: Chemically identical regardless of source

Perceived “naturalness”: While both building blocks can be natural-origin, the final triacetin is synthetically manufactured. However, when produced from vegetable-derived glycerol and fermentation-derived acetic acid, it could be considered “bio-based” or “natural-origin”—though this distinction is uncommon in food-grade triacetin.

Vegetarian/vegan/dietary status:

• Vegan: Yes—when glycerol source is plant-based (vegetable oils, biodiesel). Always vegan regardless of source (no animal products in chemical synthesis).
• Vegetarian: Yes
• Kosher: Yes (when produced from vegetable-derived sources)
• Halal: Yes (when produced from halal-compliant sources)
• Gluten-free: Yes
• Dairy-free: Yes

Natural Alternatives

Want to avoid E1518 or looking for alternative humectants and plasticizers?

Some alternatives include:

• Glycerin (E422) – Natural humectant; less effective as plasticizer; common alternative
• Propylene glycol (E1520) – Synthetic humectant and solvent
• Sorbitol (E420) – Sugar alcohol; humectant; sweetener
• Xylitol (E967) – Sugar alcohol; humectant; sweetener
• Honey – Natural humectant; retains moisture
• Corn syrup – Natural humectant; less effective
• Vegetable oils – For flavor carriers (different properties)
• Beeswax – For chewing gum texture (traditional alternative)
• Gum bases – For chewing gum without synthetic plasticizers
• Simply accept texture changes: Products will dry out faster, harden, or become less soft without humectant/plasticizer

Comparison to Related Compound E1517

E1518 vs E1517 (Glycerol Diacetate): Both are acetylated glycerol derivatives. E1517 has two acetate groups; E1518 has three. E1518 is more hydrophobic and more plasticizing than E1517. E1518 is more commonly used.

The Bottom Line

E1518 (glycerol triacetate/triacetin) is a synthetic humectant and plasticizer used primarily to soften products, retain moisture, and carry flavorings—most famously in chewing gum, but also in baked goods, candies, and other processed foods.

It’s approved by the FDA, EU, JECFA, and regulatory bodies worldwide as a safe food additive.

Key advantages: E1518 is safe at food use levels. FDA GRAS approval (since 1975, 50+ years) demonstrates regulatory confidence. No documented adverse effects. Metabolized to glycerol and acetic acid (normal diet components). Extensive pharmaceutical and cosmetic use confirms safety. EU authorization for specific applications reflects safety assessment.

For consumers: E1518 is safe when encountered in food products. While synthetic, it’s explicitly approved by all major regulatory authorities. If preferring natural alternatives, glycerin (E422) offers similar humectant properties, though with less plasticizing effect.

Primary application: E1518 is irreplaceable in chewing gum manufacturing—providing the soft, flexible texture that consumers expect. It’s also invaluable in baked goods for moisture retention and shelf life extension.

Historical perspective: The 50+ year history of FDA GRAS approval (since 1975) without any safety revisions or concerns demonstrates regulatory confidence in E1518’s safety profile.