Glycerin Specifications
Glycerin Grades Comparison
What are the differences between Crude Glycerin, Technical Grade Glycerin, and USP Grade Glycerin? What are the Glycerin Specifications? Below is a clear comparison of the three main grades, including their typical properties and uses. SRS International specializes in producing high-quality technical and USP-grade glycerin from biodiesel and oleochemical processes.
Glycerin Specifications Comparison Table
| Properties | Crude Glycerin | Technical Grade Glycerin | 99.7% USP Grade Glycerin |
|---|---|---|---|
| Glycerol Content | 40–88% | 98.0% Min | 99.70% |
| Ash | 2.0% Max | N/A | N/A |
| Moisture Content | N/A | 2.0% Max | 0.3% Max |
| Chlorides | N/A | 10 ppm Max | 10 ppm Max |
| Color | N/A | 40 Max (Pt-Co) | 10 Max (APHA) |
| Specific Gravity | N/A | 1.262 (@25°C) | 1.2612 Min |
| Sulfate | N/A | N/A | 20 ppm Max |
| Assay | N/A | N/A | 99.0–101.0% (dry basis) |
| Heavy Metals | N/A | 5 ppm Max | 5 ppm Max |
| Chlorinated Compounds | N/A | 30 ppm Max | 30 ppm Max |
| Residue on Ignition | N/A | N/A | 100 ppm Max |
| Fatty Acid & Ester | N/A | 1.00 Max | 1.000 Max |
| Water | 12.0% Max | 5.0% Max | 0.5% Max |
| pH (10% Solution) | 4.0–9.0 | 4.0–9.1 | N/A |
| DEG and Related Compounds | N/A | N/A | Pass |
| Organic Volatile Impurities | N/A | N/A | Pass |
| Organic Residue | 2.0% Max | 2.0% Max | N/A |
Crude Glycerin
Crude glycerin typically contains significant amounts of methanol, water, soaps, and salts. Its glycerol content usually ranges from 40% to 88%. Most crude glycerin is a natural by-product of biodiesel production, specifically from the transesterification process. Therefore, crude glycerin often requires further refinement to meet specific uses or standards.
Technical Grade Glycerin
In contrast, technical grade glycerin is a more refined, high-purity product. It is typically water-white, with most contaminants completely removed. Unlike crude glycerin, technical grade glycerin contains no methanol, soaps, salts, or other foreign materials. Notably, SRS International biodiesel plants, unlike many competitors, produce technical grade glycerin right from the start, ensuring a high-quality product.
USP Grade Glycerin
USP Grade Glycerin is a pharmaceutical-grade product that meets stringent US Pharmacopeia (USP 30) specifications. It is suitable for use in food, personal care, cosmetics, pharmaceuticals, and other specialty applications. This grade of glycerin is highly purified to meet the rigorous standards required in these industries.
What Classifies Glycerin as USP Grade?
FDA regulations mandate systematic record keeping by all USP glycerin manufacturers. These companies must maintain supported documentation for every shipment, including lot numbers and permits, to trace the product back to its production plant. This ensures transparency and accountability throughout the supply chain.
USP Grade Glycerin assures buyers of the product’s integrity, which cannot be achieved through physical and chemical testing alone. In contrast, Technical Grade Glycerin is not subject to such stringent governmental regulatory control. Although it is produced through similar processes, Technical Grade Glycerin does not need to meet USP or FCC requirements or comply with FDA regulations. Instead, this grade only needs to meet specifications mutually agreed upon by the buyer and seller.
In conclusion, while USP Grade Glycerin offers the assurance of compliance with rigorous standards, Technical Grade Glycerin provides more flexibility in production and distribution. Understanding these differences is essential when selecting the right grade for your needs.
Also check out, “Profitable Glycerin“