Product Overview & China Production Capacity
Propylene Glycol (PG, CAS 57-55-6, molecular formula C₃H₈O₂, MW 76.09) is a colorless, viscous liquid serving as a solvent, humectant, co-emulsifier, and preservative enhancer in pharmaceutical, food, and cosmetic formulations. China’s annual propylene glycol production capacity exceeds 2.5 million metric tons, driven by propylene oxide hydration processes at large-scale petrochemical complexes in Shandong, Jiangsu, and Zhejiang provinces. This massive production base enables USP/EP-grade supply at competitive pricing significantly below global market averages.
In pharmaceutical applications, propylene glycol solubilizes poorly water-soluble APIs, serves as a vehicle for oral, topical, and injectable formulations, and functions as a humectant in semi-solid dosage forms. It is miscible with water and most organic solvents, providing exceptional formulation versatility. Chinese producers achieve pharma-grade purity (≥99.5%) through fractional distillation with dedicated production lines segregated from industrial-grade operations.
Manufacturing Standards & Quality Assurance
Facilities operate under ISO 9001:2015, FDA registration, and kosher/halal certifications. Quality testing encompasses assay (GC), specific gravity, refractive index, acidity, water content, chloride, sulfate, heavy metals, residual ethylene glycol, and diethylene glycol content. All pharma-grade batches meet USP/NF, EP, FCC, and ChP monograph specifications with full compliance to ICH Q3C residual solvent guidelines.
Automated distillation systems with multi-column purification achieve purity levels exceeding 99.8%. In-line GC analysis monitors product composition in real time. Dedicated pharma-grade storage tanks prevent cross-contamination with industrial grades. Each batch is released only after comprehensive analytical testing and QA review.
Technical Specifications
| Parameter | Specification |
|---|---|
| CAS Number | 57-55-6 |
| Molecular Formula | C₃H₈O₂ |
| Molecular Weight | 76.09 g/mol |
| Appearance | Colorless viscous liquid |
| Assay (GC) | ≥99.5% |
| Specific Gravity (25 °C) | 1.035–1.037 |
| Water Content | ≤0.2% |
| Acidity (as Lactic Acid) | ≤0.005% |
| Heavy Metals (Pb) | ≤5 ppm |
| Pharmacopoeial Compliance | USP/NF, EP, FCC, ChP |
Packaging & Export Logistics
Propylene glycol is supplied in 215 kg steel drums, 1,000 kg IBC totes, or ISO tank containers for bulk orders. All containers meet UN transport specifications and food-contact regulatory requirements. Lead time is 5–10 business days. Shipments from Qingdao, Shanghai, Nanjing, or Ningbo under FOB, CIF, or DDP terms.
Documentation includes CoA, SDS, kosher/halal certificates, and customs paperwork. Propylene glycol is classified as non-hazardous for transport, simplifying logistics and reducing shipping costs.
China Supply Advantage
China’s integrated propylene-to-propylene glycol production chains deliver USP-grade PG at 20–35% below landed costs from Western sources. Scale advantages, modern facilities, and competitive energy costs combine to ensure pricing stability. Chinese PG producers serve the world’s leading pharmaceutical, food, and e-liquid manufacturers with proven quality consistency across millions of kilograms shipped annually. Direct manufacturer engagement provides volume discounts, flexible payment terms, and dedicated technical consultation for formulation development.