PROPANE-1,2-DIOL (PROPYLENE GLYCOL) (E1520)

Propane-1,2-diol (Propylene Glycol) (E1520) is a colorless, nearly odorless, viscous liquid organic compound used as a food additive, pharmaceutical excipient, cosmetic ingredient, and industrial formulation aid.
Propane-1,2-diol (Propylene Glycol) (E1520) is widely used as a humectant, solvent, and carrier for flavourings, colorants, and other additives in food, and as an antifreeze component in industrial cooling and heating systems.
Propane-1,2-diol (Propylene Glycol) (E1520) is authorized as a food additive under E1520 in the European Union with a safe daily intake of 25 mg per kg of body weight established by EFSA, and is recognized as GRAS by the US FDA for food manufacturing.

CAS Number: 57-55-6 (racemate); 4254-15-3 (S-enantiomer)
EC Number: 200-338-0
Molecular Formula: C3H8O2
Molecular Weight: 76.09 g/mol

Synonyms: Propane-1,2-diol, Propylene Glycol, E1520, 1,2-Propanediol, 1,2-Dihydroxypropane, α-Propylene Glycol, Methyl Ethyl Glycol, Methylethylene Glycol, Methyl Glycol, PG, 1,2-PG, Propan-1,2-diol

Propane-1,2-diol (Propylene Glycol) (E1520) is a synthetic diol alcohol with the chemical formula CH3CH(OH)CH2OH, classified as an aliphatic diol due to its two alcohol groups.
Propane-1,2-diol (Propylene Glycol) (E1520) is chiral and commercial products are typically the racemate, while the S-isomer can be produced by biotechnological routes.

Propane-1,2-diol (Propylene Glycol) (E1520) is miscible with water, ethanol, acetone, and chloroform, and is a highly effective solvent for a broad range of substances including fats, oils, waxes, and resins.
Propane-1,2-diol (Propylene Glycol) (E1520) is strongly hygroscopic, meaning it attracts and binds water molecules from its surroundings, keeping food products and cosmetics moist and preventing drying out.

Propane-1,2-diol (Propylene Glycol) (E1520) is produced industrially mainly from propylene oxide derived from petroleum by non-catalytic high-temperature hydrolysis at 200 to 220 degrees C, or by catalytic hydrolysis at 150 to 180 degrees C.
Propane-1,2-diol (Propylene Glycol) (E1520) can also be obtained from glycerol, a byproduct from biodiesel production, though this route is mainly reserved for industrial-grade material.

Propane-1,2-diol (Propylene Glycol) (E1520) is approved for food use in the EU under E1520 and as E490 in cosmetics and pharmacology; it is also present as a raw material in propylene glycol alginate (E405).
Propane-1,2-diol (Propylene Glycol) (E1520) is suitable for vegetarians and vegans as it contains no animal-derived ingredients, and is gluten free.

Uses of Propane-1,2-diol (Propylene Glycol) (E1520):
Propane-1,2-diol (Propylene Glycol) (E1520) is used in the food industry as an anticaking agent, emulsifier, flavor agent, humectant, texturizer, stabilizer, solvent, antioxidant, antimicrobial agent, and thickener.
Propane-1,2-diol (Propylene Glycol) (E1520) is used in baked goods, candies, confections and frostings, frozen dairy products, desserts, beverages, salad dressings, pastries, icing, ice cream, puddings, sauces, soups, sweet foods, flavoring mixes, and popcorn.

Propane-1,2-diol (Propylene Glycol) (E1520) functions as a solvent and carrier in the preparation and dilution of flavors, fragrances, and vitamins to distribute them evenly throughout the end product.
Propane-1,2-diol (Propylene Glycol) (E1520) is an ideal solvent for food colorings due to its miscibility with a broad range of solvents, its non-volatility, and its low cost.

Propane-1,2-diol (Propylene Glycol) (E1520) is used in bread and pastry manufacturing to reduce production time, extend shelf life, and maintain moisture, preventing the aging of baked goods.
Propane-1,2-diol (Propylene Glycol) (E1520) is used as a raw material to produce propylene glycol alginate (E405), a thickener, and propylene glycol esters of fatty acids, an emulsifier.

Propane-1,2-diol (Propylene Glycol) (E1520) is used in animal feed as a humectant to attract and hold water, keep feed moist and fresh, and enable use in zero-temperature conditions by reducing the freezing point of water.
Propane-1,2-diol (Propylene Glycol) (E1520) is used in cosmetics and personal care products including deodorants, makeup, shampoo, lotion, hair products, soap, toothpaste, wipes, creams, and serums as a humectant, skin conditioner, solvent, and viscosity controller.

Propane-1,2-diol (Propylene Glycol) (E1520) is used in pharmaceuticals as a solvent and carrier for oral, injectable, and topical formulations, and as an excipient in capsule preparations, artificial tears, and inhalation products including e-cigarette liquids.
Propane-1,2-diol (Propylene Glycol) (E1520) is used as an aircraft de-icing and anti-icing fluid, automotive antifreeze, marine antifreeze, coolant for engine cooling systems, and for winterizing plumbing systems in vacant structures.

Propane-1,2-diol (Propylene Glycol) (E1520) is used as a chemical feedstock for the production of unsaturated polyester resins, epoxy resins, polyurethane resins, and water-based acrylic architectural paints.
Propane-1,2-diol (Propylene Glycol) (E1520) is used in heat-transfer fluids and antifreezes for ventilation, heating, air-conditioning, food-processing cooling systems, and heat-exchange equipment.

Propane-1,2-diol (Propylene Glycol) (E1520) is used for creating theatrical smoke and fog in special effects for film and live entertainment by aerosolizing a mixture of propylene glycol and water.
Propane-1,2-diol (Propylene Glycol) (E1520) is used as a wetting agent in baby wipes, for trapping and preserving insects as a DNA preservative, as a surfactant in photography, as an ingredient in couplants for ultrasonic testing, and as an additive in PCR reactions.

Benefits or Advantages of Propane-1,2-diol (Propylene Glycol) (E1520):
Propane-1,2-diol (Propylene Glycol) (E1520) is authorized as safe for food use by both the FDA and EFSA and is recognized as GRAS for food manufacturing.
Propane-1,2-diol (Propylene Glycol) (E1520) is versatile across multiple sectors including food, pharmaceutical, cosmetic, and industrial applications, providing humectancy, solvency, and carrier functions in a single ingredient.

Propane-1,2-diol (Propylene Glycol) (E1520) has excellent humectant properties that help retain moisture in foods, cosmetics, and pharmaceutical preparations, extending shelf life and preventing drying.
Propane-1,2-diol (Propylene Glycol) (E1520) is miscible with water and a broad range of organic solvents, making it an extremely effective carrier and solvent for flavors, fragrances, colorants, and active ingredients.

Propane-1,2-diol (Propylene Glycol) (E1520) has a low freezing point of -59 degrees C, making it highly effective as an antifreeze component in automotive, aviation, and industrial cooling applications.
Propane-1,2-diol (Propylene Glycol) (E1520) is readily biodegradable and is a safer substitute for ethylene glycol antifreeze due to its lower environmental and toxicological profile.

Propane-1,2-diol (Propylene Glycol) (E1520) is suitable for all religious diets, vegetarians, and vegans.
Propane-1,2-diol (Propylene Glycol) (E1520) is gluten free and contains no known allergens.

Features of Propane-1,2-diol (Propylene Glycol) (E1520):
Propane-1,2-diol (Propylene Glycol) (E1520) is a colorless, hygroscopic, viscous liquid that is nearly odorless and has a slightly sweet faint taste.
Propane-1,2-diol (Propylene Glycol) (E1520) is completely miscible with water, ethanol, diethyl ether, acetone, and chloroform.

Propane-1,2-diol (Propylene Glycol) (E1520) has a high boiling point of approximately 188 degrees C and a low melting point of approximately -59 degrees C.
Propane-1,2-diol (Propylene Glycol) (E1520) has a very low vapor pressure of 0.08 mmHg at 20 degrees C, making it non-volatile under normal conditions.

Propane-1,2-diol (Propylene Glycol) (E1520) is available in pharmaceutical grade (purity ≥99.8%, USP/EP standard), food grade (purity ≥99.5%, FCC standard), and industrial grade (purity ≥99.0%).

Chemical Properties of Propane-1,2-diol (Propylene Glycol) (E1520):
Propane-1,2-diol (Propylene Glycol) (E1520) is an aliphatic diol with two hydroxyl groups, classified as a glycol, giving it both hydrophilic and reactive characteristics.
Propane-1,2-diol (Propylene Glycol) (E1520) is metabolized in the human body mainly into pyruvic acid, lactic acid, and acetic acid, which are normal metabolic intermediates processed through standard energy pathways.

Propane-1,2-diol (Propylene Glycol) (E1520) is stable under normal storage conditions but may react with strong oxidizing agents, strong acids, acid chlorides, and acid anhydrides.
Propane-1,2-diol (Propylene Glycol) (E1520) is combustible at elevated temperatures, with a flash point of approximately 99 degrees C and an autoignition temperature of approximately 415 degrees C (779 degrees F).

Propane-1,2-diol (Propylene Glycol) (E1520) has a dielectric constant of 32.0, a LogP of -0.92, a surface tension of 35.44 mN/m at 298.15 K, and a predicted pKa of 14.49.

Production and Chemical Reactions of Propane-1,2-diol (Propylene Glycol) (E1520):
Propane-1,2-diol (Propylene Glycol) (E1520) is industrially produced mainly by the hydration of propylene oxide derived from petroleum, using either a non-catalytic high-temperature process at 200 to 220 degrees C or a catalytic method at 150 to 180 degrees C in the presence of ion exchange resin or sulfuric acid.
Propane-1,2-diol (Propylene Glycol) (E1520) can also be produced by reacting propylene with chlorinated water to form 1-chloro-2-propanol followed by hydrolysis with sodium carbonate, or by glycerin hydrogenolysis using vegetable-derived glycerin and hydrogen with a catalyst.

Propane-1,2-diol (Propylene Glycol) (E1520) final industrial products contain approximately 20% propylene glycol, 1.5% dipropylene glycol, and small amounts of other polypropylene glycols before further purification to 99.5% or greater purity.
Propane-1,2-diol (Propylene Glycol) (E1520) reacts with propylene oxide to give oligomers and polymers used to produce polyurethanes, and reacts with maleic anhydride and isophthalic acid to produce unsaturated polyester resins.

Propane-1,2-diol (Propylene Glycol) (E1520) quality control checks parameters such as purity, moisture (≤0.2%), color (APHA ≤10), density (1.036 to 1.040 g/cm3), refractive index (1.431 to 1.433), heavy metals (≤5 ppm), and pH (5% solution 6.0 to 8.0).

Material Safety Data Sheet (MSDS) of Propane-1,2-diol (Propylene Glycol) (E1520):

Handling of Propane-1,2-diol (Propylene Glycol) (E1520):
Propane-1,2-diol (Propylene Glycol) (E1520) should be handled in accordance with good industrial hygiene and safety practices.
Propane-1,2-diol (Propylene Glycol) (E1520) handling requires avoiding breathing mist, vapor, or aerosol, and avoiding prolonged or repeated contact with skin and eyes.

Propane-1,2-diol (Propylene Glycol) (E1520) should be used in a well-ventilated area, and local exhaust ventilation is recommended if mist, vapor, aerosol, or spray formation may occur.
Propane-1,2-diol (Propylene Glycol) (E1520) handling requires washing hands thoroughly after handling and before eating, drinking, or smoking.

SDS of Propane-1,2-diol (Propylene Glycol) (E1520):

Stability and Reactivity of Propane-1,2-diol (Propylene Glycol) (E1520):

Chemical stability:
Propane-1,2-diol (Propylene Glycol) (E1520) is stable under normal recommended storage and handling conditions.

Reactivity:
Propane-1,2-diol (Propylene Glycol) (E1520) has low reactivity under normal use conditions.
It may react with strong oxidizing agents, strong acids, acid chlorides, acid anhydrides, and highly reactive chemicals.

Conditions to avoid:
Excessive heat.
Open flames and sparks.
Hot surfaces.
Direct sunlight.
Prolonged exposure to air or moisture.

Incompatible materials:
Strong oxidizing agents.
Strong acids.
Strong bases.
Acid chlorides.
Acid anhydrides.
Reactive halogenated compounds.

Hazardous decomposition products:
Carbon monoxide (CO).
Carbon dioxide (CO2).
Aldehydes and irritating organic vapors.
Irritating smoke.

Handling and Storage of Propane-1,2-diol (Propylene Glycol) (E1520):

Handling:
Handle in accordance with good industrial hygiene and safety practices.
Avoid breathing mist, vapor, or aerosol.
Avoid prolonged or repeated contact with skin and eyes.

Storage:
Store in a cool, dry, and well-ventilated area.
Keep containers tightly closed when not in use.
Store at +5 degrees C to +30 degrees C.
Store away from heat, ignition sources, oxidizing agents, and incompatible chemicals.
Keep in original, properly labeled containers suitable for glycols and organic liquids.

First Aid Measures of Propane-1,2-diol (Propylene Glycol) (E1520):

Inhalation:
Move the person to fresh air and keep comfortable for breathing.
Under normal conditions, inhalation of vapors is not expected to present a significant hazard.
If mist or aerosol exposure causes respiratory discomfort, seek medical attention.

Skin contact:
Wash affected skin with plenty of water and soap.
Remove contaminated clothing and wash before reuse.
Seek medical advice if redness, irritation, or signs of allergic reaction develop.

Eye contact:
Rinse eyes carefully with plenty of water for several minutes.
Remove contact lenses if present and easy to do.
Seek medical attention if irritation persists.

Ingestion:
Rinse mouth with water.
Do not induce vomiting unless instructed by medical personnel.
If a large amount is swallowed or symptoms occur, seek medical attention.

Notes for physician:
Treat symptomatically.
No specific antidote is required.

Firefighting Measures of Propane-1,2-diol (Propylene Glycol) (E1520):

Suitable extinguishing media:
Water spray.
Alcohol-resistant foam.
Dry chemical powder.
Carbon dioxide (CO2).

Unsuitable extinguishing media:
Do not use a strong direct water jet as it may spread burning liquid.

Specific hazards:
Propane-1,2-diol (Propylene Glycol) (E1520) is combustible at elevated temperatures.
Combustion may produce carbon monoxide, carbon dioxide, aldehydes, irritating smoke, and harmful organic vapors.

Protective equipment for firefighters:
Wear full protective clothing and self-contained breathing apparatus (SCBA).
Cool exposed containers with water spray from a safe distance.

Firefighting advice:
Prevent contaminated firefighting water from entering drains, soil, or waterways.

Accidental Release Measures of Propane-1,2-diol (Propylene Glycol) (E1520):

Personal precautions:
Ensure adequate ventilation.
Avoid breathing mist, vapor, or aerosol.
Remove ignition sources if safe to do so.
Use appropriate personal protective equipment.

Environmental precautions:
Prevent large quantities from entering drains, surface water, groundwater, and soil.
Large releases may increase biochemical oxygen demand and reduce dissolved oxygen in water.

Cleanup methods:
Contain the spill with inert absorbent materials such as sand, earth, or vermiculite.
Collect absorbed material into suitable labeled waste containers.
Clean contaminated surfaces with water and detergent.
Dispose of waste according to local, regional, and national regulations.

Exposure Controls / Personal Protective Equipment of Propane-1,2-diol (Propylene Glycol) (E1520):

Engineering controls:
Provide adequate general ventilation.
Use local exhaust ventilation where mist, vapor, aerosol, or spray formation is possible.
Emergency eyewash stations and safety showers should be available where the product is handled in large quantities.

Respiratory protection:
Not normally required under standard handling conditions with adequate ventilation.
Use an approved respirator suitable for organic vapors and particulates if mist, aerosol, or high vapor concentrations may occur.

Eye protection:
Wear safety glasses with side shields or chemical safety goggles.
Use face protection when splashing is possible.

Hand protection:
Wear nitrile rubber, butyl rubber, or other chemically resistant gloves when prolonged or repeated contact may occur.

Skin and body protection:
Wear suitable protective clothing or apron when handling large quantities or when splashing may occur.

Hygiene measures:
Do not eat, drink, or smoke while handling the product.
Wash hands and exposed skin thoroughly after use.
Remove contaminated clothing and wash before reuse.

Identifiers of Propane-1,2-diol (Propylene Glycol) (E1520):
E Number: E1520
INS Number: 1520
CAS No.: 57-55-6 (racemate)
EC No.: 200-338-0
FEMA Number: 2940
UNII: 6DC9Q167V3
RTECS Number: TY2000000
JECFA Number: 925
ECHA InfoCard: 100.000.307
CompTox Dashboard (EPA): DTXSID0021206
InChIKey: DNIAPMSPPWPWGF-UHFFFAOYSA-N
Function: Humectant, solvent, carrier, emulsifier, antifreeze component, pharmaceutical excipient

Properties of Propane-1,2-diol (Propylene Glycol) (E1520):
Physical state: Liquid
Appearance: Clear, colorless viscous liquid
Odor: Odorless or very slight alcoholic odor
Color: APHA ≤10
Density: 1.036 g/mL at 25 degrees C; specific gravity 1.038 (20/20°C)
Melting point: Approximately -59 to -60 degrees C
Boiling point: Approximately 187 to 188.2 degrees C
Flash point: Approximately 99 degrees C (closed cup); 225 degrees F (open cup)
Autoignition temperature: 779 degrees F (415 degrees C)
Explosive limits: 2.4 to 17.4% (V)
Vapor pressure: 0.08 mmHg at 20 degrees C
Vapor density: 2.62 (vs air)
Refractive index: n20/D 1.432
Optical rotation: -0.11° (C=1.00 g/100 mL, CHCl3)
Viscosity: 0.042 Pa·s
pH: 6 to 8 (100 g/L, H2O, 20 degrees C)
Dielectric constant: 32.0
LogP: -0.92
Surface tension: 35.44 mN/m at 298.15 K
pKa: 14.49 ± 0.20 (predicted)
Solubility in water: Miscible
Solubility in ethanol: Miscible
Solubility in diethyl ether: Miscible
Solubility in acetone: Miscible
Solubility in chloroform: Miscible
Hygroscopic: Yes

Specifications of Propane-1,2-diol (Propylene Glycol) (E1520):
Chemical name: Propane-1,2-diol (Propylene Glycol)
Purity (Pharmaceutical grade): ≥99.8% (USP/EP)
Purity (Food grade): ≥99.5% (FCC)
Purity (Industrial grade): ≥99.0%
Moisture: ≤0.2%
Color (APHA): ≤10
Density: 1.036 to 1.040 g/cm3 at 20 degrees C
Refractive index: 1.431 to 1.433
Heavy metals: ≤5 ppm
pH (5% solution): 6.0 to 8.0
FDA maximum limits in food: 2.0% general food; 2.5% frozen dairy products; 5.0% alcoholic beverages; 5.0% nuts; 24% confections and frostings; 97% seasonings and flavorings
Storage conditions: Store at +5 to +30 degrees C in tightly closed containers

Names of Propane-1,2-diol (Propylene Glycol) (E1520):
Propane-1,2-diol
Propylene Glycol
E1520
INS 1520
1,2-Propanediol
1,2-Dihydroxypropane
α-Propylene Glycol
Methyl Ethyl Glycol
Methylethylene Glycol
Methyl Glycol
PG
1,2-PG
Propan-1,2-diol