Functional Solvent Overview

• 🏭 Manufacturer: Multiple global suppliers (fragrance-grade)

• 🔎 Chemical Name: Oxydipropanol

• 🧪 Synonyms: Dipropylene glycol, DPG, Oxydipropyl alcohol

• 🧬 Chemical Formula: C₆H₁₄O₃

• 📂 CAS N°: 25265-71-8

• 📘 FEMA: Not listed (not applicable to food)

• ⚖️ MW: 134.17 g/mol

• 📝 Odor Type: Neutral

• 📈 Odor Strength: Very low

• 👃🏼 Odor Profile: Nearly odorless to faintly sweet (trace)

• ⚗️ Uses: Solvent, Fixative, Humectant

• 🧴 Appearance: Clear, colorless, viscous liquid

What is Dipropylene Glycol?

Dipropylene Glycol (DPG) is a colorless, low-volatility glycol widely used as a solvent and carrier fluid. It is typically produced as a co-product in the manufacture of propylene glycol and is available in several grades (industrial, fragrance, and high-purity).

Historical Background

The use of glycols in perfumery and personal care dates back to the early 20th century, but dipropylene glycol became commercially prominent in the 1950s alongside growing demand for stable, low-volatility solvents. As production of propylene oxide increased for polymers and antifreeze, DPG emerged as a high-performance secondary material, particularly valued in fragrance design and room-freshening applications for its low vapor pressure and broad compatibility.

Olfactory Profile & Perfumery Applications

DPG is virtually odorless, especially in high-purity grades, and does not contribute to the fragrance profile. However, its solvent behavior directly impacts the performance of volatile ingredients.

Solvent & Carrier for Fragrance Oils

In fine fragrance and air care applications, DPG is a non-reactive, stable, and low-odor solvent ideal for diluting essential oils and aromatic compounds. It improves solubility and consistency, making it indispensable for:

• Alcohol-free perfumes

• Reed diffusers

• Incense formulations

• Potpourri oils

Fixative and Evaporation Modulator

DPG slows down the evaporation of volatile aroma molecules, extending the fragrance's longevity when used in sprays or room fresheners.

3. Ingredient in Cosmetic Formulas

Thanks to its moisture-retaining and skin-compatible properties, DPG is also used in:

• Lotions

• Hair styling products

• Deodorants

• Shaving gels

Compatibility and Stability

Highly miscible with water, alcohols, and many aromatic oils, DPG acts as a bridge between hydrophilic and lipophilic substances, enhancing overall formulation stability.

Regulatory & Safety Overview

• IFRA: Not restricted (no limitation in Categories 1–12)

• CIR Review: Confirmed safe for topical use in rinse-off and leave-on products

• EU Cosmetics Regulation: Permitted with no specific concentration limits

• FEMA GRAS: Not applicable (non-food use only)

• Toxicology:

  • Low acute toxicity

  • Non-sensitizing

  • Minimal dermal and ocular irritation in cosmetic grade

Fragrance-grade DPG should not be confused with industrial-grade DPG, which may contain impurities and should not be used on skin.

Environmental Impact

• Biodegradability: Readily biodegradable under aerobic conditions

• Aquatic Toxicity: Low

• Bioaccumulation: Not expected

• Air Emissions: Low vapor pressure minimizes VOC release in standard applications

• Waste Handling: Dispose according to local chemical waste regulations; avoid environmental discharge of industrial-grade DPG

Additional Information

• Boiling Point: ~230 °C

• Flash Point: ~124 °C (closed cup)

• Density @ 20 °C: ~1.02 g/cm³

• Viscosity: Moderate to high, temperature-dependent

• Solubility:

  • Miscible with water, ethanol, glycerol, and glycols

  • Compatible with esters, aldehydes, and many perfumery raw materials

• Format Compatibility: Excellent in oil blends, sprays, roll-ons, and emulsions

• Storage Conditions: Store sealed, in a cool, dry place away from strong oxidants

Sources

• Scentspiracy-provided source

• PubChem Database – Dipropylene Glycol

• CIR Final Safety Assessment (2020)

• IFRA Standards Library (2024)

• ECHA Substance Database

• Sell, C. (2006). The Chemistry of Fragrances

• Arctander, S. (1960). Perfume and Flavor Chemicals