Propylene Glycol USP Grade

Product Overview

Propylene Glycol USP Grade is a colorless, odorless, hygroscopic liquid with a low toxicity profile, widely used as a solvent and humectant in pharmaceutical, cosmetic, and industrial applications. Its chemical formula is C₃H₈O₂, and it exists as a diol that provides excellent miscibility with water and organic solvents. The product meets USP-NF Monograph standards, ensuring traceability to recognized pharmacopeial specifications and consistent quality across production lots. With a typical assay of 99.9 wt% and stringent control of impurities such as chlorides, nitrates, and heavy metals, this propanediol supports demanding formulation requirements while maintaining process reliability.

USP Grade Propylene Glycol is engineered for stability under standard storage and handling conditions, offering a controlled vapor pressure profile and a low residue on ignition. It is compatible with HDPE and glass containers, and its low odor and low vapor emissions make it suitable for sensitive environments. The product is commonly used as a solvent, humectant, and plasticizer in cosmetic and pharmaceutical formulations, as well as a component in HPLC mobile phases and antifreeze systems where non-toxicity and regulatory compliance are essential.

Key Properties

• Property Name: Assay (wt%), Value: 99.5–100.5 (typical 99.9)
• Chemical Formula: C₃H₈O₂
• Molecular Weight: 76.09 g/mol
• Boiling Point: 188.2°C
• Specific Gravity (20°C): 1.033–1.039 (typical 1.036)
• Specific Gravity (25°C): 1.034–1.040 (typical 1.036)
• Residue on Ignition (wt% max): 0.005 (typical 0.001)
• Chloride (ppm max): 20 (typical 5)
• Nitrate (ppm max): 10 (typical 3)
• Ammonium (ppm max): 1 (typical 0.2)
• Sulfate (ppm max): 15 (typical 5)
• Water (wt% max): 0.5 (typical 0.1)
• Arsenic (ppm max): 0.01 (typical 0.005)
• Heavy Metals (as Pb, ppm max): 0.2 (typical 0.05)
• Iron (ppm max): 0.2 (typical 0.05)
• Copper (ppm max): 0.1 (typical 0.02)
• Cadmium/Manganese/Nickel/Lead/Zinc/Chromium/Cobalt/Calcium/Magnesium/Potassium/Sodium (ppm max): various, per ICP-OES with typicals well below limits
• Flash Point: 97°C

Common Applications

• HPLC Mobile Phase: Used as a primary or co-solvent component in reversed-phase chromatography for reliable separation of organic compounds in analytical workflows.
• Humectant in Food Products: Acts as a moisture-retaining agent, helping to preserve texture and prevent crystallization in formulated foods.
• Solvent for Pharmaceuticals: Serves as a pharmaceutically acceptable solvent in drug formulations and manufacturing processes.
• Antifreeze Agent: Non-toxic antifreeze and de-icing agent for industrial cooling systems where lower toxicity is advantageous.
• Cosmetic Ingredient: Employed as a moisturizer and solvent in skincare, haircare, and cosmetic formulations to improve texture and product stability.

Safety Precautions

Handle Propylene Glycol USP Grade in a well-ventilated area, away from heat, sparks, and open flames. Store in cool, dry conditions in materials compatible with glycols, such as HDPE or glass. Use appropriate PPE including chemical-resistant gloves and safety goggles during handling to prevent skin and eye contact, and ensure proper ventilation to minimize inhalation exposure. The material is stored and conveyed in accordance with USP specifications and relevant regulatory guidelines.

In case of exposure, follow standard first aid procedures: for eyes, rinse cautiously with water for several minutes; for skin, wash with soap and water and seek medical advice if irritation occurs; if inhaled, move to fresh air; if ingested, rinse mouth and seek medical attention if symptoms occur. This product is not regulated as a hazardous material for transport under typical consumer-industrial use, but SDS guidance should be consulted for detailed emergency procedures and spill response. Always reference the Safety Data Sheet prior to use and follow institutional safety policies.

Benefits

✔ High Purity USP Grade – Meets USP-NF monograph requirements with tight impurity control for pharmaceutical and analytical use.
✔ Excellent Solvent and Humectant Properties – Broad miscibility with water and organics supports diverse formulations and analytical methods.
✔ Low Toxicity and Regulatory Compliance – Non-toxic profile suitable for pharmaceutical and cosmetic applications with recognized standards.
✔ Stable Storage Profile – Low vapor pressure and controlled residue on ignition enable reliable shelf-life and process reliability.