Purchasing Guide
Dow vs SK vs Shell Propylene Glycol: 2025–2026 COA Comparison
A Detailed Comparison Based on Original Manufacturer COAs
Henan Tongshang has conducted a detailed analysis based on the latest original manufacturer Certificate of Analysis (COA) documents from 2026.
By comparing the key quality indicators of Dow Propylene Glycol, SK Propylene Glycol, and Shell Propylene Glycol, buyers can better understand the differences between these three popular propylene glycol brands and make a more suitable purchasing decision.
1. Basic Information Comparison
| Item | Dow Propylene Glycol | SK Propylene Glycol | Shell Propylene Glycol |
|---|---|---|---|
| Origin | Thailand Plant | South Korea | Huizhou, China (CNOOC and Shell Petrochemicals Co., Ltd.) |
| Batch No. | C815Q23A11 | KI8111PU2D | MPGZC02T12 |
| Production Date | 2026/02/03 | 2025/08/11 | 2026/02/02 |
| Expiry Date | 2028/02/03 | 2027/08/10 | 2028/02/02 |
| Standards | USP / EP / FCC / JP (Pharmaceutical Grade) | USP / EP / IP | USP / CP / GB29216 (Food Grade) |
Note: Dow and Shell are 2026 production batches, while SK is a 2025 batch. All products are within their valid shelf life.
2. Key Quality Indicators Comparison
| Test Item | Unit | General Standard | Dow Result | SK Result | Shell Result | Analysis |
|---|---|---|---|---|---|---|
| Propylene Glycol Purity | % | ≥99.8 | 99.99 | 99.99 | >99.90 | All three products achieve excellent purity |
| Monoethylene Glycol (EG) | % | ≤0.1 | <0.0080 | 0 | <0.0005 | Shell demonstrates extremely strict internal control |
| Diethylene Glycol (DEG) | % | ≤0.1 | <0.0080 | 0 | <0.0005 | Shell demonstrates excellent impurity control |
| Water Content | % | ≤0.2 | 0.004 | 0.004 | Meets standard | All three have extremely low moisture content |
| Color (APHA) | – | ≤10 | 2 | 2.0 | 2 | All are highly transparent |
| Chloride | ppm | ≤1 | <1.0 | <0.1 | 0.01 | Shell shows the lowest chloride content |
| Sulfate | ppm | ≤20 | <20 | <1.0 | Meets standard | SK shows excellent sulfate control |
| Residue on Ignition | ppm | ≤50 | 2 | 6.0 | <10 | Dow shows the lowest residue level |
| Iron | ppm | ≤0.5 | 0.02 | 0.02 | 0.004 | Shell shows the lowest iron content |
| Heavy Metals | ppm | ≤5 | <5.0 | <1.0 | <5 | SK demonstrates strict heavy metal control |
| Lead | ppm | ≤1 | <1.0 | <1.0 | <0.020 | Shell shows extremely low lead content |
| Acidity | ml | ≤0.2 | Pass | 0.02 | 0.01 | Shell shows the lowest acidity value |
3. Understanding the Key Indicators
1. EG / DEG (Ethylene Glycol / Diethylene Glycol)
These are among the most important safety-related impurities in propylene glycol.
Lower EG and DEG content means:
- Higher product safety
- Better compliance for food, cosmetic, and pharmaceutical applications
- Lower risk during export inspections
2. Water Content
Lower moisture content helps:
- Maintain product stability
- Reduce potential quality changes during storage
- Improve suitability for sensitive formulations
3. Lead and Heavy Metals
These indicators are especially important for:
- Pharmaceutical applications
- High-end cosmetics
- Export products
Lower levels provide better compliance with strict regulatory requirements.
4. Color Value
Lower APHA color value means:
- Better transparency
- Better appearance in cosmetics
- Better suitability for clear formulations and high-end products
4. Overall Comparison Summary
| Comparison Item | Result |
|---|---|
| Purity Performance | All three exceed 99.9%, with no significant difference |
| Impurity Control | Shell shows excellent control, followed by SK and Dow |
| Safety Indicators | Shell performs particularly well in lead and trace impurity control |
| Batch Freshness | Dow and Shell are 2026 batches; SK is 2025 batch |
| Compliance | All meet USP and food-grade related requirements |
5. How to Choose the Right Propylene Glycol?
1. Recommended Choice: Shell Propylene Glycol
Suitable for:
- High-end food applications
- Export cosmetics
- Pharmaceutical-related applications
- Customers requiring fresh production batches
Advantages:
- Strict internal quality control
- Excellent control of trace impurities
- Low lead content
- Fast delivery with China warehouse inventory
- Competitive supply capability
2. For Imported Brand Preference: SK Propylene Glycol
Suitable for:
- Customers requiring imported raw materials
- High-end export applications
Advantages:
- Korean original manufacturer supply
- Excellent EG/DEG control
- Strict sulfate and heavy metal management
- Transparent quality documentation
3. For Global Brand Recognition: Dow Propylene Glycol
Suitable for:
- General food applications
- Cosmetic manufacturing
- Customers requiring international brand recognition
Advantages:
- Globally recognized brand
- Stable international supply chain
- Pharmaceutical-grade certifications
- Widely accepted in international markets
Conclusion
Dow, SK, and Shell propylene glycol are all high-quality products that meet food-grade and USP-related requirements.
The best choice depends on your specific application requirements, quality standards, import preference, and supply conditions.
Henan Tongshang specializes in imported chemical raw material supply, including:
- Propylene Glycol
- Glycerin
- Vaccine Adjuvants
- Polyethylene Glycol (PEG)
For original COA documents, latest quotations, samples, and product information, please contact Henan Tongshang.