This comparison explores the technical and functional differences between Pale Pressed Grade (PPG) and First Pressed Degummed (FPD) castor oil. Both are high-quality products derived from the first pressing of the seed, but they serve different industrial purposes based on their refinement levels.
In the professional castor oil market, choosing between Pale Pressed Grade (PPG) and First Pressed Degummed (FPD) depends on whether your application prioritizes visual clarity and low acidity (PPG) or thermal stability and the absence of gums (FPD).
While both grades originate from the first mechanical pressing of the castor seed, their post-extraction treatments define their industrial utility.
Executive Summary
-
Pale Pressed Grade (PPG) is a highly refined oil, often referred to as “Refined Castor Oil.” It undergoes bleaching and fine filtration to achieve a light color and low acid value.
-
First Pressed Degummed (FPD) is a grade where the primary focus is the removal of plant-based gums and phospholipids. It retains the natural lubricating properties of castor oil while ensuring the oil does not “char” or leave carbon deposits under high heat.
Technical Specification Comparison Table
| Parameter | Pale Pressed Grade (PPG) | First Pressed Degummed (FPD) |
| Appearance | Clear, Very Pale Yellow | Brilliant Clear, Yellowish |
| Lovibond Color (5¼” Cell) | Max 10.0 Yellow / 1.0 Red | Max 20.0 – 30.0 Yellow / 2.0 Red |
| Gardner Color | Max 1 – 2 | Max 6 – 7 |
| Acid Value (mg KOH/g) | Max 2.0 | Max 2.0 |
| Free Fatty Acids (FFA %) | Max 1.0% | Max 1.0% |
| Moisture & Volatiles | Max 0.25% | Max 0.50% – 0.75% |
| Insoluble Impurities | Max 0.02% | Max 0.05% |
| Hydroxyl Value | 160 – 168 | 160 – 168 |
| Iodine Value | 82 – 90 | 82 – 90 |
| Saponification Value | 177 – 185 | 177 – 187 |
Key Differentiators: From A to Z
1. Processing and Purity
PPG is the result of a comprehensive refining process that includes bleaching. This removes almost all pigments and microscopic impurities. FPD, on the other hand, specifically targets “gums” (phosphatides). While FPD is very clean, it does not undergo the same intensive color-stripping (bleaching) as PPG.
2. Visual Clarity (Color)
The most immediate difference is the color. PPG is designed for applications where the oil must not alter the final color of a product (like clear plastics or white creams). FPD has a more natural yellow hue, which is perfectly acceptable for industrial lubricants and heavy machinery fluids.
3. Thermal Behavior (Degumming)
The “Degumming” in FPD is its most critical feature. When standard castor oil is heated, the gums can burn, creating carbon buildup and “varnish” on machinery parts. By removing these gums, FPD ensures that the oil remains stable and clean even in high-friction or high-heat environments.
4. Moisture and Volatiles
PPG typically has lower moisture content (Max 0.25%) compared to FPD (up to 0.75%). This makes PPG slightly more stable for chemical reactions where water molecules might interfere with the process, such as in polyurethane synthesis.
Industry Applications
Where to use Pale Pressed Grade (PPG):
-
Pharmaceuticals & Cosmetics: Used as a high-purity carrier oil for ointments, hair care, and skin lotions.
-
High-End Coatings: Ideal for clear varnishes and lacquers where transparency is vital.
-
Dielectric Fluids: Used in electrical condensers due to its purity and insulating properties.
-
Specialty Polymers: A base for manufacturing high-quality resins and plastics.
Where to use First Pressed Degummed (FPD):
-
High-Performance Lubricants: The “gold standard” for racing engines and industrial machinery where gum buildup must be avoided.
-
Hydraulic Fluids: Used in systems requiring consistent viscosity and clean operation.
-
Textile Chemicals: Functions as a high-quality wetting and finishing agent.
-
Feedstock for Derivatives: Often used as a clean starting material for producing other industrial castor derivatives.
Pros and Cons
Pale Pressed Grade (PPG)
-
Pros: Exceptional color clarity, extremely low impurities, high versatility for sensitive formulations.
-
Cons: Generally higher cost due to the intensive bleaching and refining stages.
First Pressed Degummed (FPD)
-
Pros: Excellent thermal stability, prevents carbon buildup, superior for moving parts/machinery.
-
Cons: Not suitable for products requiring a completely colorless base; slightly higher moisture than PPG.
The Verdict: Which one should you choose?
If your product is color-sensitive (like cosmetics, clear inks, or white coatings) or requires the highest chemical purity, Pale Pressed Grade (PPG) is the best choice.
If your application involves high heat, friction, or machinery (like lubricants or hydraulic systems) and you need to prevent carbon deposits and gumming, First Pressed Degummed (FPD) offers the best performance and value.
