E1518 TRIACETIN

E1518 Triacetin is a synthetic food additive and industrial chemical, the triester formed from glycerol and acetic acid, which serves as a flavor solvent and carrier, humectant, plasticizer and emulsifier across the food, pharmaceutical, cosmetic, tobacco and industrial sectors.
E1518 Triacetin, known in the trade as glyceryl triacetate or glycerol triacetate, is prepared when all three hydroxyl groups of glycerol are esterified with acetic acid or acetic anhydride; the result is a clear, colorless, oily and viscous liquid with a barely noticeable fruity aroma and a gentle sweetness that becomes bitter once the concentration passes 0.05%.
E1518 Triacetin is authorized as a food additive in the European Union under Regulation (EC) No 1333/2008 with the E number E1518, is regarded as generally recognized as safe (GRAS) by the US FDA under 21 CFR 184.1901, and holds Codex Alimentarius INS number 1518 and JECFA number 920, which together support its established safety profile for food, pharmaceutical and cosmetic use.

CAS Number: 102-76-1
EC Number (EINECS): 203-051-9
Molecular Formula: C9H14O6
Molecular Weight: 218.205 g/mol

Synonyms: Triacetin, Glyceryl Triacetate, Glycerol Triacetate, Glycerin Triacetate, Triacetylglycerol, 1,2,3-Triacetoxypropane, 1,2,3-Propanetriol Triacetate, Propane-1,2,3-triyl Triacetate, 1,2,3-Triacetylglycerol, Triacetine, Glycerol Trisacetate, GTA, GTC, E1518, A1518 (Australian code), CAS 102-76-1

E1518 Triacetin differs chemically from monoacetin (E1516, glyceryl monoacetate) and diacetin (E1517, glyceryl diacetate) because it is the only one of the three in which every hydroxyl group of glycerol has been acetylated.
E1518 Triacetin was first prepared in 1854 by the French chemist Marcellin Berthelot from glycerol and acetic acid, commercial production started in the 1920s for use as a plasticizer and solvent, and it has been listed in the SCOGS (Select Committee on GRAS Substances) database since 1975.

E1518 Triacetin belongs to the high production volume chemicals reviewed by the OECD, with an estimated global output of 10,000–50,000 tonnes a year, of which Japan contributes about 5,000 tonnes, underlining its role as an industrial commodity.
E1518 Triacetin is not classified as a hazardous substance or mixture under the GHS/CLP Regulation (EC) No 1272/2008 or as dangerous under Directive 67/548/EEC, which points to a generally favorable safety and regulatory profile for industrial and consumer uses.

E1518 Triacetin is found in nature only in minute quantities, for instance in papaya, while the material sold commercially is made synthetically and, in standard grade, carries under 0.1% diacetin and 0.01% monoacetin as impurities.
E1518 Triacetin acts as a slow-release ester prodrug of the short-chain fatty acid acetate: pancreatic and gastric lipases cleave it into glycerol and three molecules of acetate, and it has been studied for possible use in parenteral nutrition, in the management of irritable bowel syndrome and as a dietary supplement.

Uses of E1518 Triacetin:
E1518 Triacetin is used in the food industry as a solvent and carrier for fat-soluble and water-soluble flavorings and colorants in chewing gum, confectionery, baked goods, beverages and coating or glazing formulations, spreading them evenly without changing their technological function.
E1518 Triacetin keeps products such as chewing gum, baked goods, sausage casings, jams, jellies and marmalades from drying out, since it is hygroscopic and holds onto moisture, which preserves texture and extends shelf life.

E1518 Triacetin is used as a plasticizer and softener in chewing gum base, giving the gum matrix its flexibility and chewiness, and in edible coatings, casings and confectionery where the texture needs to be softened.
E1518 Triacetin helps oil and water phases combine in dairy desserts, salad dressings, dairy products and other food systems, thereby improving the stability of the finished product.

E1518 Triacetin is used widely in pharmaceutical formulations as a humectant, plasticizer and solvent, for example in oral capsule shells, controlled-release film coatings, topical ointments, cough syrups, elixirs, expectorants, lozenges and transdermal patches.
E1518 Triacetin regulates the release of active substances in delivery systems such as push-pull osmotic pumps and biodegradable phospholipid gels, which have been developed for site-specific delivery of drugs like paclitaxel in cancer therapy.

E1518 Triacetin is used as the main plasticizer and bonding agent for cellulose acetate fiber filters in cigarette manufacturing, which makes it one of its largest industrial applications worldwide.
E1518 Triacetin plasticizes cellulose acetate, polyvinyl alcohol (PVOH), starch and other cellulose-based plastics and resins, and in doing so improves their flexibility, processability, tensile behavior and biodegradability.

E1518 Triacetin is used as a fuel additive and antiknock agent for gasoline and to improve the low-temperature viscosity of biodiesel blends.
E1518 Triacetin acts as a solvent in printing inks, wall coatings for buildings, cosmetics such as nail polish and skin care products, perfumery and leather tanning, and as a core sand binder in foundries.

E1518 Triacetin is used in membrane preparation as a greener substitute for highly toxic diluents, in line with the 12 Principles of Green Chemistry on less hazardous chemical synthesis.
E1518 Triacetin provides antifungal action in pharmaceutical preparations and fixes flavor as well as dissolving it in oleoresins and alcohol-free flavor concentrates.

Benefits or Advantages of E1518 Triacetin:
E1518 Triacetin is broken down in the body by pancreatic and gastric lipases into glycerol and acetic acid, both natural metabolic compounds, and it is therefore regarded as safe to consume, with an oral LD50 of 3 g/kg in rats that indicates low acute toxicity.
E1518 Triacetin rests on a broad regulatory footing: the US FDA recognizes it as GRAS, JECFA has assigned an ADI of "not specified" and GHS/CLP does not classify it as hazardous, so it can be used in food, pharmaceuticals and cosmetics in many jurisdictions.

E1518 Triacetin has a high flash point of 138°C (closed cup) and an autoignition temperature of 430°C, which provides good fire safety in manufacturing and processing at the temperatures typical of the food and pharmaceutical industries.
E1518 Triacetin fits the requirements of all religious groups, vegetarians and vegans provided it is made from synthetic or plant-derived glycerol, and short-term repeated-inhalation studies in animals have found it non-toxic.

E1518 Triacetin supplies acetate to the gut and the body as a prodrug and may raise levels of the butyrate-producing gut bacterium Faecalibacterium prausnitzii, which suggests a possible alternative to dietary fiber for irritable bowel syndrome patients who cannot tolerate fiber because of gas and bloating.
E1518 Triacetin has been proposed as a food energy source for artificial food regeneration systems on long space missions, and the evidence indicates that taking more than half of dietary energy from E1518 Triacetin would be safe.

Features of E1518 Triacetin:
E1518 Triacetin is a colorless to very pale yellow, oily and viscous liquid at room temperature, with a very faint, slightly fatty and fruity smell, a mildly sweet taste below 500 ppm that turns bitter above 0.05%, and a density of about 1.155–1.160 g/cm³ at 20°C.
E1518 Triacetin solidifies only at about -78°C and boils near 259°C at 760 mmHg, so it stays liquid across a very wide temperature span; its viscosity is roughly 17–23 mPa·s at 20–25°C and its refractive index n25/D is 1.430–1.431.

E1518 Triacetin is slightly soluble in water (6.1 g/100 mL), fully miscible with ethanol, acetone, benzene, diethyl ether, ethyl acetate and chloroform, and partly miscible with fats, and its logP of 0.25–0.35 points to low lipophilicity and moderate hydrophilicity.
E1518 Triacetin evaporates hardly at all, with a vapor pressure below 0.01 mmHg at 25°C (1 Pa at 37.6°C), so volatility is negligible in ordinary handling and the inhalation risk is minimal.

Chemical Properties of E1518 Triacetin:
E1518 Triacetin is the triester of glycerol (propane-1,2,3-triol) and acetic acid, in which all three hydroxyl groups carry acetyl groups (-OCOCH₃); its structural formula is C₃H₅(OCOCH₃)₃, its molecular formula is C₉H₁₄O₆ and its molecular weight is 218.205 g/mol.
E1518 Triacetin is characterized thermodynamically by a standard enthalpy of formation ΔfH°298 of -1330.8 kJ/mol, a standard enthalpy of combustion ΔcH°298 of 4211.6 kJ/mol, an enthalpy of vaporization of 85.74 kJ/mol, a heat capacity of 389 J·mol⁻¹·K⁻¹ and a standard molar entropy S°298 of 458.3 J·mol⁻¹·K⁻¹.

E1518 Triacetin is chemically stable under ordinary conditions and across a pH range of 5.0–7.0; it can react with strong oxidizing agents, may react with metals and can damage rayon fabric on contact.
E1518 Triacetin breaks down stepwise in acidic or alkaline media into diacetin, monoacetin, glycerol and acetic acid, while in the body the main route is enzymatic hydrolysis by pancreatic and gastric lipases.

Production of E1518 Triacetin:
E1518 Triacetin is manufactured industrially by reacting glycerol with acetic anhydride: 3(CH₃CO)₂O + C₃H₅(OH)₃ → C₃H₅(OCOCH₃)₃ + 3CH₃COOH, or by esterifying glycerol with glacial acetic acid at elevated temperature in the presence of an acid catalyst such as sulfuric acid or potassium hydrogen sulfate.
E1518 Triacetin can be obtained in 99% yield using catalytic sodium hydroxide with microwave irradiation, or in the same yield using a silica-supported cobalt(II) Salen catalyst at 50°C in 55 minutes, and a further route reacts oxygen with allyl acetate and acetic acid in the liquid phase over a bromide salt catalyst.

E1518 Triacetin is produced in a closed reaction system; the commercial product contains less than 0.1% diacetin and 0.01% monoacetin as impurities and is offered in food grade (purity ≥99.5%), foundry grade (purity ≥99%) and pharmaceutical grade (Ph Eur, BP, ChP, USP) specifications.
E1518 Triacetin is supplied for large-scale industrial use in 240 kg drums, 1,150 kg IBC containers and 22–25 tonne ISO tanks.

Stability and Reactivity of E1518 Triacetin:

Chemical stability:
E1518 Triacetin is stable under ordinary conditions and in the pH range of 5.0–7.0.

Reactivity:
E1518 Triacetin may react with strong oxidizing agents and is incompatible with metals.
E1518 Triacetin hydrolyzes under strongly acidic or alkaline conditions.

Conditions to avoid:
E1518 Triacetin should be kept away from strong oxidizing agents.
E1518 Triacetin should be kept away from metals.

E1518 Triacetin should not be exposed to strongly acidic or strongly alkaline conditions.
E1518 Triacetin should not be heated above its flash point (138°C).

Incompatible materials:
E1518 Triacetin is incompatible with strong oxidizing agents.
E1518 Triacetin is incompatible with reactive metals.

E1518 Triacetin is incompatible with concentrated strong acids.
E1518 Triacetin is incompatible with concentrated strong alkalis.

Hazardous decomposition products:
E1518 Triacetin may release carbon monoxide (CO).
E1518 Triacetin may release carbon dioxide (CO2).

E1518 Triacetin may release acetic acid vapors (on thermal decomposition or in a fire).
E1518 Triacetin may release irritating organic fumes.

Handling and Storage of E1518 Triacetin:

Handling:
E1518 Triacetin should be handled according to good industrial hygiene and safety practice.
E1518 Triacetin vapors or mist should not be inhaled; ensure adequate ventilation.
E1518 Triacetin should be kept off the eyes, skin and clothing.

E1518 Triacetin handling should be followed by thorough hand washing, and always before eating, drinking or smoking.
E1518 Triacetin handling areas must be free of eating, drinking and smoking.

Storage:
E1518 Triacetin containers should be kept tightly closed.
E1518 Triacetin should be stored in a cool, dry, well-ventilated place below 30°C.

E1518 Triacetin should be stored away from strong oxidizers, metals and heat sources.
E1518 Triacetin should be protected from direct sunlight.

E1518 Triacetin has a shelf life of 12 months in its original sealed packaging.
E1518 Triacetin is packaged in 240 kg drums, 1,150 kg IBC tanks and 22–25 tonne ISO tanks.

First Aid Measures of E1518 Triacetin:

Inhalation:
After inhalation of E1518 Triacetin vapor or mist, move the person into fresh air.
E1518 Triacetin exposure with stopped breathing calls for artificial respiration.
E1518 Triacetin exposure that causes respiratory irritation calls for medical advice.

Skin contact:
After skin contact with E1518 Triacetin, wash with soap and plenty of water.
E1518 Triacetin contact that causes skin irritation calls for medical advice.

Eye contact:
After eye contact with E1518 Triacetin, rinse at once and thoroughly with plenty of water for at least 15 minutes, keeping the eyelids open.
E1518 Triacetin eye contact calls for medical attention if irritation continues.

Ingestion:
After ingestion of E1518 Triacetin, rinse the mouth with water.
E1518 Triacetin ingestion should not be followed by induced vomiting unless medical personnel advise it.
E1518 Triacetin ingestion calls for medical advice; the oral LD50 in rats is 3 g/kg, which indicates low acute toxicity.

Firefighting Measures of E1518 Triacetin:

Suitable extinguishing media:
E1518 Triacetin fires can be fought with water spray, foam, dry chemical powder or carbon dioxide.

Specific hazards:
E1518 Triacetin is a combustible liquid with a flash point of 138°C (280°F) and an autoignition temperature of 430°C (806°F).
E1518 Triacetin has explosive limits of 1.05% (lower, at 189°F) and 7.73% (upper, at 215°F).
E1518 Triacetin may produce carbon monoxide, carbon dioxide, acetic acid vapors and irritating organic fumes on thermal decomposition or combustion.

Protective equipment for firefighters:
E1518 Triacetin fires require firefighters to wear self-contained breathing apparatus (SCBA) and full protective clothing.

Firefighting instructions:
E1518 Triacetin containers exposed to fire should be cooled with water spray.
E1518 Triacetin firefighting run-off should be kept out of drains and waterways.

Accidental Release Measures of E1518 Triacetin:

Personal precautions:
E1518 Triacetin should be kept off the eyes and skin, and spilled E1518 Triacetin creates a slipping hazard.
E1518 Triacetin spill response calls for suitable personal protective equipment.

Environmental precautions:
E1518 Triacetin must be kept out of drains and waterways; its aquatic toxicity is low (fish LC50, 96 h: >100–165 mg/L; Daphnia EC50, 48 h: ~380–811 mg/L; algae EC50, 72 h: >1,000 mg/L).

Methods for cleaning up:
E1518 Triacetin spills should be contained with an inert absorbent such as sand or vermiculite.
E1518 Triacetin waste should be collected in properly labeled containers and disposed of according to local regulations.
E1518 Triacetin residues on contaminated surfaces should be washed off with water after collection.

Exposure Controls / Personal Protective Equipment of E1518 Triacetin:

Engineering controls:
E1518 Triacetin operations should have adequate ventilation, with local exhaust ventilation where mist or vapor may form.

Eye protection:
E1518 Triacetin handling calls for safety glasses or chemical splash goggles where splashing is possible.

Hand protection:
E1518 Triacetin prolonged or repeated skin contact calls for chemical-resistant gloves.

Skin and body protection:
E1518 Triacetin handling calls for suitable protective clothing to prevent prolonged skin contact.

Respiratory protection:
E1518 Triacetin normally needs no respiratory protection under ambient conditions because of its very low vapor pressure.
E1518 Triacetin mist or vapor generated during heating or spraying calls for a suitable respirator.

Hygiene measures:
E1518 Triacetin handling should be followed by thorough hand washing, and always before eating, drinking or smoking.

Identifiers of E1518 Triacetin:
E Number: E1518
INS Number: 1518
FEMA Number: 2007
JECFA Number: 920
CAS Number: 102-76-1
EC Number (EINECS): 203-051-9
Molecular Formula: C9H14O6
Molecular Weight: 218.205 g/mol
PubChem CID: 5541
ChEBI: CHEBI:9661
ChEMBL: ChEMBL1489254
ChemSpider: 13835706
KEGG: D00384
RTECS: AK3675000
UNII: XHX3C3X673
CompTox (EPA): DTXSID3026691
ECHA InfoCard: 100.002.775
Beilstein/REAXYS: 1792353
MDL Number: MFCD00008716

HS Code: 2915.39.30
Vapor density (air=1): 7.52
NFPA: Health 1 / Flammability 1 / Reactivity 0
GHS Classification: Not classified as hazardous (CLP Regulation (EC) No 1272/2008)
GHS Signal Word: None
GHS Hazard Statements: None
US FDA: GRAS (21 CFR 184.1901); listed in the SCOGS database since 1975
EU Status: Approved food additive E1518 under Regulation (EC) No 1333/2008
REACH: Registered; no classified hazards (ECHA)
OECD HPV: Assessed; global production 10,000–50,000 tonnes/year
Dietary restrictions: Suitable for all religious groups, vegetarians and vegans (when plant-origin or synthetic)
Natural occurrence: Reported in papaya

Properties of E1518 Triacetin:
Physical state (20°C): Liquid
Appearance: Colorless to very pale yellow oily liquid
Odor: Very faint, slightly fatty, fruity
Taste: Mildly sweet below 500 ppm; bitter above 0.05%
Melting point: -78°C (-108°F)
Boiling point: 258–260°C at 760 mmHg
Flash point: 138°C (280°F, closed cup)
Autoignition temperature: 430°C (806°F)

Explosive limits: 1.05% (lower) / 7.73% (upper)
Density (20°C): 1.155–1.160 g/cm³
Density (25°C): ~1.150–1.158 g/cm³
Refractive index (n25/D): 1.429–1.431
Viscosity (20–25°C): 17–23 mPa·s
Vapor pressure (25°C): <0.01 mmHg (1 Pa at 37.6°C)
Vapor density (air=1): 7.52
Solubility in water (25°C): 6.1 g/100 mL
Solubility in ethanol: Miscible
Solubility in acetone: Very soluble
Solubility in benzene: Soluble
Solubility in diethyl ether: Soluble
logP (octanol/water): 0.25–0.35
pH (5% solution, 20°C): 5.0–7.0
Heat capacity: 389 J·mol⁻¹·K⁻¹

Enthalpy of formation (ΔfH°298): -1330.8 kJ/mol
Enthalpy of combustion (ΔcH°298): 4211.6 kJ/mol
Enthalpy of vaporization: 85.74 kJ/mol
Thermal decomposition: begins above 200°C
GHS Classification: Not classified

Specifications of E1518 Triacetin:

Food Grade:
Appearance: Colorless transparent liquid
Purity: ≥99.5%
Color (Pt-Co): ≤15
Water: ≤0.05%
Acidity (mg KOH/g): ≤0.005
Refractive index (25°C/D): 1.430–1.435
Relative density (25/25°C): 1.154–1.164
Heavy metals (as Pb): ≤5 ppm
Arsenic: ≤1 ppm

Foundry Grade:
Appearance: Colorless transparent liquid
Purity: ≥99.0%
Color (Pt-Co): ≤30
Water: ≤0.05%
Acidity (mg KOH/g): ≤0.01
Refractive index (25°C/D): 1.430–1.435
Relative density (25/25°C): 1.154–1.164
Heavy metals (as Pb): ≤5 ppm
Arsenic: ≤3 ppm

Pharmaceutical Grade: Complies with Ph Eur, BP, ChP, USP
Storage: Cool, dry, well-ventilated; keep sealed; away from oxidizers; max 30°C
Shelf life: 12 months in original sealed packaging
Packaging: 240 kg drum / 1,150 kg IBC / 22–25 tonne ISO tank

Names of E1518 Triacetin:
E1518
Triacetin
Glyceryl Triacetate
Glycerol Triacetate
Glycerin Triacetate
Triacetylglycerol
Triacetine
1,2,3-Triacetoxypropane
1,2,3-Propanetriol Triacetate
Propane-1,2,3-triyl Triacetate
1,2,3-Triacetylglycerol
Triacetyl Glycerin
Glycerol Trisacetate
GTA
GTC
A1518 (Australian food additive code)
INS 1518
FEMA 2007
CAS 102-76-1